<?xml version="1.0" encoding="us-ascii"?>
<!-- DFIN ActiveDisclosure(SM) XBRL Schema Document - http://www.dfinsolutions.com/ -->
<!-- Creation Date      : 2020-03-16T17:05:35.2971701+00:00 -->
<!-- Version            : 5.0.1.369 -->
<!-- Package ID         : 44c2be6693294e819f14e16d965a07bd -->
<!-- Copyright (c) 2020 Donnelley Financial Solutions, Inc. All Rights Reserved. -->
<xsd:schema xmlns:nonnum="http://www.xbrl.org/dtr/type/non-numeric" xmlns:num="http://www.xbrl.org/dtr/type/numeric" xmlns:sic="http://xbrl.sec.gov/sic/2011-01-31" xmlns:stpr="http://xbrl.sec.gov/stpr/2018-01-31" xmlns:naics="http://xbrl.sec.gov/naics/2017-01-31" xmlns:srt-types="http://fasb.org/srt-types/2019-01-31" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:srt="http://fasb.org/srt/2019-01-31" xmlns:us-gaap="http://fasb.org/us-gaap/2019-01-31" xmlns:dei="http://xbrl.sec.gov/dei/2019-01-31" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:country="http://xbrl.sec.gov/country/2017-01-31" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:currency="http://xbrl.sec.gov/currency/2019-01-31" xmlns:avro="http://www.avrobio.com/20191231" xmlns:us-types="http://fasb.org/us-types/2019-01-31" xmlns:exch="http://xbrl.sec.gov/exch/2019-01-31" attributeFormDefault="unqualified" elementFormDefault="qualified" targetNamespace="http://www.avrobio.com/20191231" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <xsd:import schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd" namespace="http://www.xbrl.org/2003/instance" />
  <xsd:import schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" namespace="http://www.xbrl.org/2003/linkbase" />
  <xsd:import schemaLocation="http://www.xbrl.org/2005/xbrldt-2005.xsd" namespace="http://xbrl.org/2005/xbrldt" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/country/2017/country-2017-01-31.xsd" namespace="http://xbrl.sec.gov/country/2017-01-31" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/currency/2019/currency-2019-01-31.xsd" namespace="http://xbrl.sec.gov/currency/2019-01-31" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd" namespace="http://xbrl.sec.gov/dei/2019-01-31" />
  <xsd:import schemaLocation="http://www.xbrl.org/dtr/type/nonNumeric-2009-12-16.xsd" namespace="http://www.xbrl.org/dtr/type/non-numeric" />
  <xsd:import schemaLocation="http://www.xbrl.org/dtr/type/numeric-2009-12-16.xsd" namespace="http://www.xbrl.org/dtr/type/numeric" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/exch/2019/exch-2019-01-31.xsd" namespace="http://xbrl.sec.gov/exch/2019-01-31" />
  <xsd:import schemaLocation="http://www.xbrl.org/lrr/arcrole/factExplanatory-2009-12-16.xsd" namespace="http://www.xbrl.org/2009/arcrole/fact-explanatoryFact" />
  <xsd:import schemaLocation="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd" namespace="http://www.xbrl.org/2009/role/negated" />
  <xsd:import schemaLocation="http://www.xbrl.org/lrr/role/net-2009-12-16.xsd" namespace="http://www.xbrl.org/2009/role/net" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/naics/2017/naics-2017-01-31.xsd" namespace="http://xbrl.sec.gov/naics/2017-01-31" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/sic/2011/sic-2011-01-31.xsd" namespace="http://xbrl.sec.gov/sic/2011-01-31" />
  <xsd:import schemaLocation="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd" namespace="http://fasb.org/srt/2019-01-31" />
  <xsd:import schemaLocation="http://xbrl.fasb.org/srt/2019/elts/srt-roles-2019-01-31.xsd" namespace="http://fasb.org/srt-roles/2019-01-31" />
  <xsd:import schemaLocation="http://xbrl.fasb.org/srt/2019/elts/srt-types-2019-01-31.xsd" namespace="http://fasb.org/srt-types/2019-01-31" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/stpr/2018/stpr-2018-01-31.xsd" namespace="http://xbrl.sec.gov/stpr/2018-01-31" />
  <xsd:import schemaLocation="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd" namespace="http://fasb.org/us-gaap/2019-01-31" />
  <xsd:import schemaLocation="http://xbrl.fasb.org/us-gaap/2019/elts/us-roles-2019-01-31.xsd" namespace="http://fasb.org/us-roles/2019-01-31" />
  <xsd:import schemaLocation="http://xbrl.fasb.org/us-gaap/2019/elts/us-types-2019-01-31.xsd" namespace="http://fasb.org/us-types/2019-01-31" />
  <xsd:annotation>
    <xsd:appinfo>
      <link:roleType id="TemplateLink" roleURI="http://www.avrobio.com/20191231/role/TemplateLink" xmlns:link="http://www.xbrl.org/2003/linkbase">
        <link:definition>00000 - Document - Template Link</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="avro-20191231_cal.xml" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" xlink:title="Calculation Links, all" xlink:type="simple" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" />
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="avro-20191231_def.xml" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:title="Definition Links, all" xlink:type="simple" />
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="avro-20191231_lab.xml" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:title="Label Links, all" xlink:type="simple" />
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="avro-20191231_pre.xml" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:title="Presentation Links, all" xlink:type="simple" />
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DocumentDocumentAndEntityInformation" id="Role_DocumentDocumentAndEntityInformation">
        <link:definition>100000 - Document - Document and Entity Information</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/StatementConsolidatedBalanceSheets" id="Role_StatementConsolidatedBalanceSheets">
        <link:definition>100010 - Statement - Consolidated Balance Sheets</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/StatementConsolidatedBalanceSheetsParenthetical" id="Role_StatementConsolidatedBalanceSheetsParenthetical">
        <link:definition>100020 - Statement - Consolidated Balance Sheets (Parenthetical)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/StatementConsolidatedStatementsOfOperationsAndComprehensiveLoss" id="Role_StatementConsolidatedStatementsOfOperationsAndComprehensiveLoss">
        <link:definition>100030 - Statement - Consolidated Statements of Operations and Comprehensive Loss</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/StatementConsolidatedStatementsOfRedeemableConvertiblePreferredStockAndStockholdersDeficitEquity" id="Role_StatementConsolidatedStatementsOfRedeemableConvertiblePreferredStockAndStockholdersDeficitEquity">
        <link:definition>100040 - Statement - Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders&apos; (Deficit) Equity</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/StatementConsolidatedStatementsOfRedeemableConvertiblePreferredStockAndStockholdersDeficitEquityParenthetical" id="Role_StatementConsolidatedStatementsOfRedeemableConvertiblePreferredStockAndStockholdersDeficitEquityParenthetical">
        <link:definition>100050 - Statement - Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders&apos; (Deficit) Equity (Parenthetical)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/StatementConsolidatedStatementsOfCashFlows" id="Role_StatementConsolidatedStatementsOfCashFlows">
        <link:definition>100060 - Statement - Consolidated Statements of Cash Flows</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureNatureOfBusiness" id="Role_DisclosureNatureOfBusiness">
        <link:definition>100070 - Disclosure - Nature of the Business</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPolicies" id="Role_DisclosureSummaryOfSignificantAccountingPolicies">
        <link:definition>100080 - Disclosure - Summary of Significant Accounting Policies</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureFairValueOfFinancialAssetsAndLiabilities" id="Role_DisclosureFairValueOfFinancialAssetsAndLiabilities">
        <link:definition>100090 - Disclosure - Fair Value of Financial Assets and Liabilities</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosurePrepaidExpensesAndOtherCurrentAssets" id="Role_DisclosurePrepaidExpensesAndOtherCurrentAssets">
        <link:definition>100100 - Disclosure - Prepaid Expenses and Other Current Assets</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosurePropertyAndEquipmentNet" id="Role_DisclosurePropertyAndEquipmentNet">
        <link:definition>100110 - Disclosure - Property and Equipment, Net</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureAccruedExpenses" id="Role_DisclosureAccruedExpenses">
        <link:definition>100120 - Disclosure - Accrued Expenses</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureLoanAgreementAndWarrantToPurchasePreferredStock" id="Role_DisclosureLoanAgreementAndWarrantToPurchasePreferredStock">
        <link:definition>100130 - Disclosure - Loan Agreement and Warrant to Purchase Preferred Stock</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureRedeemableConvertiblePreferredStock" id="Role_DisclosureRedeemableConvertiblePreferredStock">
        <link:definition>100140 - Disclosure - Redeemable Convertible Preferred Stock</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureCommonStock" id="Role_DisclosureCommonStock">
        <link:definition>100150 - Disclosure - Common Stock</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureStockBasedCompensation" id="Role_DisclosureStockBasedCompensation">
        <link:definition>100160 - Disclosure - Stock-Based Compensation</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureLicenseAgreements" id="Role_DisclosureLicenseAgreements">
        <link:definition>100170 - Disclosure - License Agreements</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureIncomeTaxes" id="Role_DisclosureIncomeTaxes">
        <link:definition>100180 - Disclosure - Income Taxes</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureNetLossPerShareAttributableToCommonStockholders" id="Role_DisclosureNetLossPerShareAttributableToCommonStockholders">
        <link:definition>100190 - Disclosure - Net Loss per Share Attributable to Common Stockholders</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureCommitmentsAndContingencies" id="Role_DisclosureCommitmentsAndContingencies">
        <link:definition>100200 - Disclosure - Commitments and Contingencies</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureRelatedPartyTransactions" id="Role_DisclosureRelatedPartyTransactions">
        <link:definition>100210 - Disclosure - Related Party Transactions</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureBenefitPlans" id="Role_DisclosureBenefitPlans">
        <link:definition>100220 - Disclosure - Benefit Plans</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureSubsequentEvents" id="Role_DisclosureSubsequentEvents">
        <link:definition>100230 - Disclosure - Subsequent Events</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicies" id="Role_DisclosureSummaryOfSignificantAccountingPoliciesPolicies">
        <link:definition>100240 - Disclosure - Summary of Significant Accounting Policies (Policies)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesTables" id="Role_DisclosureSummaryOfSignificantAccountingPoliciesTables">
        <link:definition>100250 - Disclosure - Summary of Significant Accounting Policies (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureFairValueOfFinancialAssetsAndLiabilitiesTables" id="Role_DisclosureFairValueOfFinancialAssetsAndLiabilitiesTables">
        <link:definition>100260 - Disclosure - Fair Value of Financial Assets and Liabilities (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosurePrepaidExpensesAndOtherCurrentAssetsTables" id="Role_DisclosurePrepaidExpensesAndOtherCurrentAssetsTables">
        <link:definition>100270 - Disclosure - Prepaid Expenses and Other Current Assets (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosurePropertyAndEquipmentNetTables" id="Role_DisclosurePropertyAndEquipmentNetTables">
        <link:definition>100280 - Disclosure - Property and Equipment, Net (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureAccruedExpensesTables" id="Role_DisclosureAccruedExpensesTables">
        <link:definition>100290 - Disclosure - Accrued Expenses (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureCommonStockTables" id="Role_DisclosureCommonStockTables">
        <link:definition>100300 - Disclosure - Common Stock (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureStockBasedCompensationTables" id="Role_DisclosureStockBasedCompensationTables">
        <link:definition>100310 - Disclosure - Stock-Based Compensation (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureIncomeTaxesTables" id="Role_DisclosureIncomeTaxesTables">
        <link:definition>100320 - Disclosure - Income Taxes (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureNetLossPerShareAttributableToCommonStockholdersTables" id="Role_DisclosureNetLossPerShareAttributableToCommonStockholdersTables">
        <link:definition>100330 - Disclosure - Net Loss per Share Attributable to Common Stockholders (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureCommitmentsAndContingenciesTables" id="Role_DisclosureCommitmentsAndContingenciesTables">
        <link:definition>100340 - Disclosure - Commitments and Contingencies (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureNatureOfBusinessAdditionalInformationDetail" id="Role_DisclosureNatureOfBusinessAdditionalInformationDetail">
        <link:definition>100350 - Disclosure - Nature of the Business - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesAdditionalInformationDetail" id="Role_DisclosureSummaryOfSignificantAccountingPoliciesAdditionalInformationDetail">
        <link:definition>100360 - Disclosure - Summary of Significant Accounting Policies - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesEstimatedUsefulLivesOfPropertyAndEquipmentDetail" id="Role_DisclosureSummaryOfSignificantAccountingPoliciesEstimatedUsefulLivesOfPropertyAndEquipmentDetail">
        <link:definition>100370 - Disclosure - Summary of Significant Accounting Policies - Estimated Useful Lives of Property and Equipment (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesStatementsOfCashFlowsSubsequentToAdoptionOfASUDetail" id="Role_DisclosureSummaryOfSignificantAccountingPoliciesStatementsOfCashFlowsSubsequentToAdoptionOfASUDetail">
        <link:definition>100380 - Disclosure - Summary of Significant Accounting Policies - Statements of cash flows subsequent to the adoption of ASU (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureFairValueOfFinancialAssetsAndLiabilitiesSummaryOfFinancialAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasisDetail" id="Role_DisclosureFairValueOfFinancialAssetsAndLiabilitiesSummaryOfFinancialAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasisDetail">
        <link:definition>100390 - Disclosure - Fair Value of Financial Assets and Liabilities - Summary of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureFairValueOfFinancialAssetsAndLiabilitiesAdditionalInformationDetail" id="Role_DisclosureFairValueOfFinancialAssetsAndLiabilitiesAdditionalInformationDetail">
        <link:definition>100400 - Disclosure - Fair Value of Financial Assets and Liabilities - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureFairValueOfFinancialAssetsAndLiabilitiesSummaryOfChangesInFairValueOfPreferredStockWarrantLiabilityForFairValueDeterminedByLevel3InputsDetail" id="Role_DisclosureFairValueOfFinancialAssetsAndLiabilitiesSummaryOfChangesInFairValueOfPreferredStockWarrantLiabilityForFairValueDeterminedByLevel3InputsDetail">
        <link:definition>100410 - Disclosure - Fair Value of Financial Assets and Liabilities - Summary of Changes in Fair Value of Preferred Stock Warrant Liability for Fair Value Determined by Level 3 Inputs (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureFairValueOfFinancialAssetsAndLiabilitiesSummaryOfChangesInFairValueOfDerivativeLiabilityForFairValueDeterminedByLevel3InputsDetail" id="Role_DisclosureFairValueOfFinancialAssetsAndLiabilitiesSummaryOfChangesInFairValueOfDerivativeLiabilityForFairValueDeterminedByLevel3InputsDetail">
        <link:definition>100420 - Disclosure - Fair Value of Financial Assets and Liabilities - Summary of Changes in Fair Value of Derivative Liability for Fair Value Determined by Level 3 Inputs (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosurePrepaidExpensesAndOtherCurrentAssetsSummaryOfPrepaidExpensesAndOtherCurrentAssetsDetail" id="Role_DisclosurePrepaidExpensesAndOtherCurrentAssetsSummaryOfPrepaidExpensesAndOtherCurrentAssetsDetail">
        <link:definition>100430 - Disclosure - Prepaid Expenses and Other Current Assets - Summary of Prepaid Expenses and Other Current Assets (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosurePropertyAndEquipmentNetSummaryOfPropertyAndEquipmentNetDetail" id="Role_DisclosurePropertyAndEquipmentNetSummaryOfPropertyAndEquipmentNetDetail">
        <link:definition>100440 - Disclosure - Property and Equipment, Net - Summary of Property and Equipment, Net (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosurePropertyAndEquipmentNetAdditionalInformationDetail" id="Role_DisclosurePropertyAndEquipmentNetAdditionalInformationDetail">
        <link:definition>100450 - Disclosure - Property and Equipment, Net - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureAccruedExpensesSummaryOfAccruedExpensesDetail" id="Role_DisclosureAccruedExpensesSummaryOfAccruedExpensesDetail">
        <link:definition>100460 - Disclosure - Accrued Expenses - Summary of Accrued Expenses (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureLoanAgreementAndWarrantToPurchasePreferredStockAdditionalInformationDetail" id="Role_DisclosureLoanAgreementAndWarrantToPurchasePreferredStockAdditionalInformationDetail">
        <link:definition>100470 - Disclosure - Loan Agreement and Warrant to Purchase Preferred Stock - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureRedeemableConvertiblePreferredStockAdditionalInformationDetail" id="Role_DisclosureRedeemableConvertiblePreferredStockAdditionalInformationDetail">
        <link:definition>100480 - Disclosure - Redeemable Convertible Preferred Stock - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureCommonStockAdditionalInformationDetail" id="Role_DisclosureCommonStockAdditionalInformationDetail">
        <link:definition>100490 - Disclosure - Common Stock - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureCommonStockSummaryOfCommonStockReservedForFutureIssuanceDetail" id="Role_DisclosureCommonStockSummaryOfCommonStockReservedForFutureIssuanceDetail">
        <link:definition>100500 - Disclosure - Common Stock - Summary of Common Stock Reserved for Future Issuance (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail" id="Role_DisclosureStockBasedCompensationAdditionalInformationDetail">
        <link:definition>100510 - Disclosure - Stock-Based Compensation - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureStockBasedCompensationSummaryOfAssumptionsThatUsedToDetermineGrantDateFairValueOfStockOptionsGrantedToEmployeesAndMembersOfBoardDetail" id="Role_DisclosureStockBasedCompensationSummaryOfAssumptionsThatUsedToDetermineGrantDateFairValueOfStockOptionsGrantedToEmployeesAndMembersOfBoardDetail">
        <link:definition>100520 - Disclosure - Stock-Based Compensation - Summary of Assumptions that Used to Determine Grant-Date Fair Value of Stock Options Granted to Employees and Members of Board (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStockOptionActivityDetail" id="Role_DisclosureStockBasedCompensationSummaryOfStockOptionActivityDetail">
        <link:definition>100530 - Disclosure - Stock-Based Compensation - Summary of Stock Option Activity (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureStockBasedCompensationSummaryOfRestrictedStockUnitActivityDetail" id="Role_DisclosureStockBasedCompensationSummaryOfRestrictedStockUnitActivityDetail">
        <link:definition>100540 - Disclosure - Stock-Based Compensation - Summary of Restricted Stock Unit Activity (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureStockBasedCompensationScheduleOfStockBasedCompensationExpenseDetail" id="Role_DisclosureStockBasedCompensationScheduleOfStockBasedCompensationExpenseDetail">
        <link:definition>100550 - Disclosure - Stock-Based Compensation - Schedule of Stock-based Compensation Expense (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureLicenseAgreementsAdditionalInformationDetail" id="Role_DisclosureLicenseAgreementsAdditionalInformationDetail">
        <link:definition>100560 - Disclosure - License Agreements - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetail" id="Role_DisclosureIncomeTaxesAdditionalInformationDetail">
        <link:definition>100570 - Disclosure - Income Taxes - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureIncomeTaxesScheduleOfReconciliationOfIncomeTaxExpenseBenefitDetail" id="Role_DisclosureIncomeTaxesScheduleOfReconciliationOfIncomeTaxExpenseBenefitDetail">
        <link:definition>100580 - Disclosure - Income Taxes - Schedule of Reconciliation of Income Tax Expense (Benefit) (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureIncomeTaxesScheduleOfDeferredTaxAssetsAndLiabilitiesDetail" id="Role_DisclosureIncomeTaxesScheduleOfDeferredTaxAssetsAndLiabilitiesDetail">
        <link:definition>100590 - Disclosure - Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureNetLossPerShareAttributableToCommonStockholdersScheduleOfDilutiveCommonStockEquivalentsExcludedFromComputationOfDilutedNetLossPerShareDetail" id="Role_DisclosureNetLossPerShareAttributableToCommonStockholdersScheduleOfDilutiveCommonStockEquivalentsExcludedFromComputationOfDilutedNetLossPerShareDetail">
        <link:definition>100600 - Disclosure - Net Loss per Share Attributable to Common Stockholders - Schedule of Dilutive Common Stock Equivalents Excluded from Computation of Diluted Net Loss per Share (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureCommitmentsAndContingenciesAdditionalInformationDetail" id="Role_DisclosureCommitmentsAndContingenciesAdditionalInformationDetail">
        <link:definition>100610 - Disclosure - Commitments and Contingencies - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureCommitmentsAndContingenciesScheduleOfFutureMinimumRentalPaymentUnderOperatingLeaseDetail" id="Role_DisclosureCommitmentsAndContingenciesScheduleOfFutureMinimumRentalPaymentUnderOperatingLeaseDetail">
        <link:definition>100620 - Disclosure - Commitments and Contingencies - Schedule Of Future Minimum Rental Payment Under Operating Lease (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureRelatedPartyTransactionsAdditionalInformationDetail" id="Role_DisclosureRelatedPartyTransactionsAdditionalInformationDetail">
        <link:definition>100630 - Disclosure - Related Party Transactions - Additional information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureBenefitPlansAdditionalInformationDetail" id="Role_DisclosureBenefitPlansAdditionalInformationDetail">
        <link:definition>100640 - Disclosure - Benefit Plans - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.avrobio.com/20191231/taxonomy/role/DisclosureSubsequentEventsAdditionalInformationDetail" id="Role_DisclosureSubsequentEventsAdditionalInformationDetail">
        <link:definition>100650 - Disclosure - Subsequent Events - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
    </xsd:appinfo>
  </xsd:annotation>
  <xsd:element id="avro_NetIncomeLossAvailableToCommonStockholdersBasicAndDiluted" name="NetIncomeLossAvailableToCommonStockholdersBasicAndDiluted" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="avro_TemporaryEquityStockIssuedDuringPeriodShareNewIssues" name="TemporaryEquityStockIssuedDuringPeriodShareNewIssues" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="avro_TemporaryEquityStockIssuedDuringPeriodSharesNewIssuesToSettledAccruedLiabilityOfLicense" name="TemporaryEquityStockIssuedDuringPeriodSharesNewIssuesToSettledAccruedLiabilityOfLicense" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="avro_TemporaryEquityStockIssuedDuringPeriodValueNewIssuesToSettledAccruedLiabilityOfLicenseCost" name="TemporaryEquityStockIssuedDuringPeriodValueNewIssuesToSettledAccruedLiabilityOfLicenseCost" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="avro_StockIssuedDuringPeriodValueCommonStockWarrantExercised" name="StockIssuedDuringPeriodValueCommonStockWarrantExercised" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="avro_StockIssuedDuringPeriodSharesCommonStockWarrantExercised" name="StockIssuedDuringPeriodSharesCommonStockWarrantExercised" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="avro_SeriesSeedConvertiblePreferredStockMember" name="SeriesSeedConvertiblePreferredStockMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_SeriesAConvertiblePreferredStockMember" name="SeriesAConvertiblePreferredStockMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_SeriesBConvertiblePreferredStockMember" name="SeriesBConvertiblePreferredStockMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_TemporaryEquityIssuanceOfRedeemableConvertiblePreferredStockNetOfIssuanceCosts" name="TemporaryEquityIssuanceOfRedeemableConvertiblePreferredStockNetOfIssuanceCosts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="avro_IssuanceOfCommonStockNetOfIssuanceCosts" name="IssuanceOfCommonStockNetOfIssuanceCosts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="avro_DeferredRentExpense" name="DeferredRentExpense" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="avro_PaymentOfDilutionLiability" name="PaymentOfDilutionLiability" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="avro_PropertyAndEquipmentHeldForSale" name="PropertyAndEquipmentHeldForSale" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="avro_DeferredOfferingCostsIncludedInAccruedExpensesAndAccountsPayable" name="DeferredOfferingCostsIncludedInAccruedExpensesAndAccountsPayable" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="avro_PurchasesOfPropertyAndEquipmentPaidForByLandlord" name="PurchasesOfPropertyAndEquipmentPaidForByLandlord" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="avro_AccretionOfIssuanceCostsRelatedToRedeemableConvertiblePreferredStock" name="AccretionOfIssuanceCostsRelatedToRedeemableConvertiblePreferredStock" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="avro_PrepaidExpensesAndOtherCurrentAssetsDisclosureTextBlock" name="PrepaidExpensesAndOtherCurrentAssetsDisclosureTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="avro_LoanAgreementAndWarrantToPurchasePreferredStockDisclosureTextBlock" name="LoanAgreementAndWarrantToPurchasePreferredStockDisclosureTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="avro_TemporaryEquityTextBlock" name="TemporaryEquityTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="avro_LicenseAgreementDisclosureTextBlock" name="LicenseAgreementDisclosureTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="avro_NetIncomeLossPerShareAttributableToCommonStockholdersPolicyTextBlock" name="NetIncomeLossPerShareAttributableToCommonStockholdersPolicyTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="avro_EmergingGrowthCompanyStatusPolicyTextBlock" name="EmergingGrowthCompanyStatusPolicyTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="avro_RecentlyAdoptedAccountingPronouncementsPolicyTextBlock" name="RecentlyAdoptedAccountingPronouncementsPolicyTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="avro_ScheduleOfPropertyPlantAndEquipmentEstimatedUsefulLifeTableTextBlock" name="ScheduleOfPropertyPlantAndEquipmentEstimatedUsefulLifeTableTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="avro_WarrantsToPurchaseRedeemableConvertiblePreferredStockMember" name="WarrantsToPurchaseRedeemableConvertiblePreferredStockMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_SignificantAccountingPoliciesAbstract" name="SignificantAccountingPoliciesAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_SignificantOfAccountingPoliciesLineItems" name="SignificantOfAccountingPoliciesLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_SignificantOfAccountingPoliciesTable" name="SignificantOfAccountingPoliciesTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_ForeignExchangeLoss" name="ForeignExchangeLoss" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="avro_DebtInstrumentFairValueCarryingValueAbstract" name="DebtInstrumentFairValueCarryingValueAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_FairValueOfAssetsAndLiabilitiesMeasuredOnNonRecurringBasisLineItems" name="FairValueOfAssetsAndLiabilitiesMeasuredOnNonRecurringBasisLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_RestrictedCashMember" name="RestrictedCashMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_FairValueInputAmountTransferBetweenLevels" name="FairValueInputAmountTransferBetweenLevels" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="avro_LicenseAgreementMember" name="LicenseAgreementMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_StockPurchaseAgreementMember" name="StockPurchaseAgreementMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityConversionPreferredWarrantsToCommonStockWarrants" name="FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityConversionPreferredWarrantsToCommonStockWarrants" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="avro_ProvisionForMaximumCashPayment" name="ProvisionForMaximumCashPayment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="avro_DilutionPaymentPayableCurrent" name="DilutionPaymentPayableCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="avro_TaxIncentiveRefundCurrent" name="TaxIncentiveRefundCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="avro_PrepaidResearchAndDevelopmentCostsCurrent" name="PrepaidResearchAndDevelopmentCostsCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="avro_AccruedResearchAndDevelopmentExpenseCurrent" name="AccruedResearchAndDevelopmentExpenseCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="avro_AdditionalStockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" name="AdditionalStockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="avro_ExercisableWarrantsToPurchaseCommonStock" name="ExercisableWarrantsToPurchaseCommonStock" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="avro_FairValueOfWarrantsAtIssuance" name="FairValueOfWarrantsAtIssuance" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="avro_SeriesARedeemableConvertiblePreferredStockMember" name="SeriesARedeemableConvertiblePreferredStockMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_SeriesBRedeemableConvertiblePreferredStockMember" name="SeriesBRedeemableConvertiblePreferredStockMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_BioMarinPharmaceuticalIncMember" name="BioMarinPharmaceuticalIncMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_TemporaryEquityStockIssuanceCosts" name="TemporaryEquityStockIssuanceCosts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="avro_UndesignatedPreferredStock" name="UndesignatedPreferredStock" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="avro_UndesignatedSharesOfPreferredStockOutstanding" name="UndesignatedSharesOfPreferredStockOutstanding" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="avro_JulyTwoThousandNineteenFollowOnOfferingMember" name="JulyTwoThousandNineteenFollowOnOfferingMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_OtherCashIssuanceCostsRelatedToOffering" name="OtherCashIssuanceCostsRelatedToOffering" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="avro_TwoThousandEighteenStockOptionAndIncentivePlanMember" name="TwoThousandEighteenStockOptionAndIncentivePlanMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_TwoThousandEighteenEmployeeStockPurchasePlanMember" name="TwoThousandEighteenEmployeeStockPurchasePlanMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_TwoThousandNineteenInducementPlanMember" name="TwoThousandNineteenInducementPlanMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_TwoThousandFifteenStockOptionAndGrantPlanMember" name="TwoThousandFifteenStockOptionAndGrantPlanMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_NumberOfSharesOfCommonStockOutstandingIncreasePercentage" name="NumberOfSharesOfCommonStockOutstandingIncreasePercentage" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="avro_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedAndExpirationsInPeriod" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedAndExpirationsInPeriod" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="avro_OptionFee" name="OptionFee" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="avro_UpfrontLicenseFees" name="UpfrontLicenseFees" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="avro_MilestonePayments" name="MilestonePayments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="avro_LicenseAgreementsAbstract" name="LicenseAgreementsAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_LicenseAgreementLineItems" name="LicenseAgreementLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_LicenseAgreementTable" name="LicenseAgreementTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_UHNagreementMember" name="UHNagreementMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_FabrylicenseagreementMember" name="FabrylicenseagreementMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_Interleukin12LicenseAgreementMember" name="Interleukin12LicenseAgreementMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_GenstemTherapeuticsIncMember" name="GenstemTherapeuticsIncMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_LundUniversityRightsHoldersAgreementMember" name="LundUniversityRightsHoldersAgreementMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_ClinicalTrialCostRelatedToResearchAndDevelopmentExpense" name="ClinicalTrialCostRelatedToResearchAndDevelopmentExpense" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="avro_MilestoneFees" name="MilestoneFees" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="avro_LicenseMaintenanceFees" name="LicenseMaintenanceFees" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="avro_PaymentsUponClosingOfInitialPublicOffering" name="PaymentsUponClosingOfInitialPublicOffering" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="avro_MilestonePayment" name="MilestonePayment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="avro_LicenseAgreementExpenses" name="LicenseAgreementExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="avro_UpfrontPaymentPaidInCash" name="UpfrontPaymentPaidInCash" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="avro_ExpirationThrough2037Member" name="ExpirationThrough2037Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_ExpirationThrough2039Member" name="ExpirationThrough2039Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_OrphanDrugCreditMember" name="OrphanDrugCreditMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_ExpirationThrough2033Member" name="ExpirationThrough2033Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_EffectiveIncomeTaxRateReconciliationPermanentDifference" name="EffectiveIncomeTaxRateReconciliationPermanentDifference" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="avro_EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsAct2017Percent" name="EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsAct2017Percent" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="avro_DeferredTaxAssetsCapitalizedStartUpAndOrganizationalCosts" name="DeferredTaxAssetsCapitalizedStartUpAndOrganizationalCosts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="avro_DeferredTaxAssetsLicenseAgreement" name="DeferredTaxAssetsLicenseAgreement" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="avro_PayrollTaxLiabilityCappedPerYear" name="PayrollTaxLiabilityCappedPerYear" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="avro_TaxCreditCarryforwardsExpirationPeriod" name="TaxCreditCarryforwardsExpirationPeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="avro_OperatingLossAndTaxCreditCarryforwardsLimitationsThresholdPercentageOfCumulativeChangesInOwnershipInterestOfSignificantShareholdersConsidered" name="OperatingLossAndTaxCreditCarryforwardsLimitationsThresholdPercentageOfCumulativeChangesInOwnershipInterestOfSignificantShareholdersConsidered" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="avro_OperatingLossAndTaxCreditCarryforwardsLimitationsPeriodOverWhichCumulativeChangesInOwnershipInterestOfSignificantShareholdersConsidered" name="OperatingLossAndTaxCreditCarryforwardsLimitationsPeriodOverWhichCumulativeChangesInOwnershipInterestOfSignificantShareholdersConsidered" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="avro_OperatingLeaseAnnualIncreaseInRentalPercentage" name="OperatingLeaseAnnualIncreaseInRentalPercentage" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="avro_CommitmentsAndContingenciesDisclosureLineItems" name="CommitmentsAndContingenciesDisclosureLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_CommitmentsAndContingenciesDisclosureTable" name="CommitmentsAndContingenciesDisclosureTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_SubleaseAgreementMember" name="SubleaseAgreementMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_OfficersAndBoardMembersMember" name="OfficersAndBoardMembersMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_ConsultingServicesAgreementMember" name="ConsultingServicesAgreementMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_DefinedContributionPlanEmployerContributionAmount" name="DefinedContributionPlanEmployerContributionAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="avro_DefinedBenefitPlansAbstract" name="DefinedBenefitPlansAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="avro_ShelfRegistrationMaximumEquityOfferingPrice" name="ShelfRegistrationMaximumEquityOfferingPrice" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="avro_UnderwrittenPublicOfferingMember" name="UnderwrittenPublicOfferingMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
</xsd:schema>
