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  <xsd:element id="fdmt_DueToFromCustomer" name="DueToFromCustomer" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fdmt_IncreaseInSharesAvailableForIssuancePercentage" name="IncreaseInSharesAvailableForIssuancePercentage" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_OptionsToPurchaseOrdinaryShares" name="OptionsToPurchaseOrdinaryShares" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_SponsoredResearchAgreementsMember" name="SponsoredResearchAgreementsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_FutureSalesBasedMilestonePaymentsExpectedPaymentsMultiplesOfActualAwardReceived" name="FutureSalesBasedMilestonePaymentsExpectedPaymentsMultiplesOfActualAwardReceived" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_AggregateFairValueOfMarketableSecuritiesInUnrealizedGainPosition" name="AggregateFairValueOfMarketableSecuritiesInUnrealizedGainPosition" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fdmt_AdditionalInvestmentInCash" name="AdditionalInvestmentInCash" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_PercentageOfEquityInterestUponClosingOfFirstQualifiedFinancingAtOption" name="PercentageOfEquityInterestUponClosingOfFirstQualifiedFinancingAtOption" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_CollaborationAndLicenseRevenueMember" name="CollaborationAndLicenseRevenueMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_ActualAwardPaymentPeriodUponFirstCommercialSaleOfProduct" name="ActualAwardPaymentPeriodUponFirstCommercialSaleOfProduct" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_CysticFibrosisFoundationMember" name="CysticFibrosisFoundationMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_CysticFibrosisFoundationAgreementMember" name="CysticFibrosisFoundationAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfDurationPurchasePeriod" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfDurationPurchasePeriod" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_FutureSalesBasedMilestonePaymentExpectedPaymentsMultiplesOfActualAwardReceived" name="FutureSalesBasedMilestonePaymentExpectedPaymentsMultiplesOfActualAwardReceived" type="xbrli:pureItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_AdjustmentsToAdditionalPaidInCapitalVestingOfStockWarrantIssuedForServices" name="AdjustmentsToAdditionalPaidInCapitalVestingOfStockWarrantIssuedForServices" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_AstellasGeneTherapiesIncMember" name="AstellasGeneTherapiesIncMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_FairValueOfNonMonetaryConsiderationOfIntellectualPropertyRight" name="FairValueOfNonMonetaryConsiderationOfIntellectualPropertyRight" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fdmt_ShareBasedCompensationArrangementByShareBasedPaymentAwardStockOverlappingOfferingPeriod" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardStockOverlappingOfferingPeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAvailableForGrant" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAvailableForGrant" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_OrganizationAndNatureOfBusinessTable" name="OrganizationAndNatureOfBusinessTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfOutstandingStockIncreasedAnnuallyForFutureIssuance" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfOutstandingStockIncreasedAnnuallyForFutureIssuance" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_ScheduleOfCommonSharesReservedForFutureIssuanceTableTextBlock" name="ScheduleOfCommonSharesReservedForFutureIssuanceTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_SummaryOfSignificantAccountingPoliciesTable" name="SummaryOfSignificantAccountingPoliciesTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_AggregateUnrealizedLoss" name="AggregateUnrealizedLoss" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fdmt_PercentageOfEquityInterestsIssuedAsCommonStock" name="PercentageOfEquityInterestsIssuedAsCommonStock" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_OtherRisksAndUncertaintiesPolicyPolicyTextBlock" name="OtherRisksAndUncertaintiesPolicyPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_VestingPeriodOfShareAwards" name="VestingPeriodOfShareAwards" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_UnpaidOfferingCosts" name="UnpaidOfferingCosts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_CommitmentAndContingenciesLineItems" name="CommitmentAndContingenciesLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_CollaborativeArrangementsRoyaltiesMultiplesOnActualAwardReceived" name="CollaborativeArrangementsRoyaltiesMultiplesOnActualAwardReceived" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_StockIssuedDuringPeriodValueNetUnrealizedGainLossOnSaleOfMarketableSecurities" name="StockIssuedDuringPeriodValueNetUnrealizedGainLossOnSaleOfMarketableSecurities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_ContingentPaymentsEliminated" name="ContingentPaymentsEliminated" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fdmt_ClassOfWarrantsExpense" name="ClassOfWarrantsExpense" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fdmt_MaximumUnrealizedLossAtIndividualInstrumentLevel" name="MaximumUnrealizedLossAtIndividualInstrumentLevel" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fdmt_CustomerMember" name="CustomerMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_VestingOfCommonStockWarrantInReturnForServices" name="VestingOfCommonStockWarrantInReturnForServices" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fdmt_CollaborativeArrangementResearchAndDevelopmentMilestonesEntitledToReceiveForEachLicensedProduct" name="CollaborativeArrangementResearchAndDevelopmentMilestonesEntitledToReceiveForEachLicensedProduct" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fdmt_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFour" name="LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFour" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_AdditionalFundingCommitted" name="AdditionalFundingCommitted" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_FairValueLiabilitiesLevelOneAndLevelTwoTransfersAmount" name="FairValueLiabilitiesLevelOneAndLevelTwoTransfersAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fdmt_CollaborativeArrangementReceiveFutureOptionFeesAndMilestones" name="CollaborativeArrangementReceiveFutureOptionFeesAndMilestones" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fdmt_FiveEightFiveEightHortonStreetBuildingLeaseAndExpansionMember" name="FiveEightFiveEightHortonStreetBuildingLeaseAndExpansionMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_AstellasMember" name="AstellasMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_EmployeeStockPurchasePlanSharesExpectedToBeIssuedMember" name="EmployeeStockPurchasePlanSharesExpectedToBeIssuedMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_SeriesCRedeemableConvertiblePreferredStockMember" name="SeriesCRedeemableConvertiblePreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_WarrantExercisedMonthAndYear" name="WarrantExercisedMonthAndYear" type="xbrli:gYearMonthItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_PotentialCashPaymentUponAchievementOfCertainLateStageDevelopmentRegulatoryAndSalesMilestones" name="PotentialCashPaymentUponAchievementOfCertainLateStageDevelopmentRegulatoryAndSalesMilestones" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_NumberOfWarrantSharesIssued" name="NumberOfWarrantSharesIssued" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_ResearchAndDevelopmentExpenseRelatedParty" name="ResearchAndDevelopmentExpenseRelatedParty" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fdmt_FiveNineEightZeroHortonStreetMember" name="FiveNineEightZeroHortonStreetMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_AmendedUniQureAgreementMember" name="AmendedUniQureAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_NumberOfInstallmentsToPayActualAward" name="NumberOfInstallmentsToPayActualAward" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_TwoThousandTwentyEmployeeStockPurchasePlanMember" name="TwoThousandTwentyEmployeeStockPurchasePlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_BuildingLeaseMember" name="BuildingLeaseMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_IncurredExpenses" name="IncurredExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fdmt_TwoThousandFourteenPlanMember" name="TwoThousandFourteenPlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_WarrantExpiresYear" name="WarrantExpiresYear" type="xbrli:gYearItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_SummaryOfSignificantAccountingPoliciesLineItems" name="SummaryOfSignificantAccountingPoliciesLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_LicenseAgreementWithUniversityOfPennsylvaniaMember" name="LicenseAgreementWithUniversityOfPennsylvaniaMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_OtherImpairmentChargesRelatedToMarketableSecurities" name="OtherImpairmentChargesRelatedToMarketableSecurities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_AevitasTherapeuticsIncAgreementMember" name="AevitasTherapeuticsIncAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_ClassOfWarrantExpense" name="ClassOfWarrantExpense" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_AtmOfferingProgramMember" name="AtmOfferingProgramMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_AmountPaidToRelatedParty" name="AmountPaidToRelatedParty" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_CorporateBondMember" name="CorporateBondMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_MachineLearningSponsoredResearchAgreementMember" name="MachineLearningSponsoredResearchAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_OtherImpairmentChargeRelatedToMarketableSecurities" name="OtherImpairmentChargeRelatedToMarketableSecurities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fdmt_FairValueOfOptions" name="FairValueOfOptions" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_NonRefundableLicenseFeePayableUponExecution" name="NonRefundableLicenseFeePayableUponExecution" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_IncreaseDecreaseInContractWithCustomerRevenueRecognized" name="IncreaseDecreaseInContractWithCustomerRevenueRecognized" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_IssuanceOfCommonStockUponExerciseOfStockOptionsAndWarrants" name="IssuanceOfCommonStockUponExerciseOfStockOptionsAndWarrants" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fdmt_SponsoredResearchAgreementsAndMachineLearningSponsoredResearchAgreementsMember" name="SponsoredResearchAgreementsAndMachineLearningSponsoredResearchAgreementsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_AccruedAndOtherCurrentLiabilitiesTextBlock" name="AccruedAndOtherCurrentLiabilitiesTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_ProceedsFromTenantImprovementAllowance" name="ProceedsFromTenantImprovementAllowance" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fdmt_CustomerAMember" name="CustomerAMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_NumberOfAgreementsEntered" name="NumberOfAgreementsEntered" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_LiabilityContingentConsiderationForFutureMilestoneAndRoyaltyPayments" name="LiabilityContingentConsiderationForFutureMilestoneAndRoyaltyPayments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_AmountObligatedToPayNonRefundableLicenseFeeAnnually" name="AmountObligatedToPayNonRefundableLicenseFeeAnnually" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_OfferingCostsMember" name="OfferingCostsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_LeaseIncentiveLiability" name="LeaseIncentiveLiability" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_MinimumPercentageOfOutstandingSharesHeldByIndividual" name="MinimumPercentageOfOutstandingSharesHeldByIndividual" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_FundingAgreementMember" name="FundingAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_UniQureAgreementMember" name="UniQureAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_CollaborativeArrangementRoyaltiesMultiplesOnActualAwardReceived" name="CollaborativeArrangementRoyaltiesMultiplesOnActualAwardReceived" type="xbrli:pureItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_CollaborativeArrangementContributionUponDevelopmentMilestone" name="CollaborativeArrangementContributionUponDevelopmentMilestone" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_ChoroideremiaResearchFoundationAgreementMember" name="ChoroideremiaResearchFoundationAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_TwoThousandTwentyThreeFollowOnPublicOfferingMember" name="TwoThousandTwentyThreeFollowOnPublicOfferingMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_ContinuousPeriodWhereCompanyCeasesToDevelopOrCommercializeAnyProduct" name="ContinuousPeriodWhereCompanyCeasesToDevelopOrCommercializeAnyProduct" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_OperatingLeaseTermExtendedExpirationPeriod" name="OperatingLeaseTermExtendedExpirationPeriod" type="xbrli:gYearMonthItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_LicenseArrangementsAbstract" name="LicenseArrangementsAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_TotalAmountOfAwardUnderAgreement" name="TotalAmountOfAwardUnderAgreement" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_ShortTermMarketableSecuritiesMember" name="ShortTermMarketableSecuritiesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_FairValueAssumptionsProbabilityOfChangeInControlEventPercentage" name="FairValueAssumptionsProbabilityOfChangeInControlEventPercentage" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_DeferredAtmCostsReclassification" name="DeferredAtmCostsReclassification" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fdmt_AmendedUniqureAgreementAndSecondUniqureAgreementMember" name="AmendedUniqureAgreementAndSecondUniqureAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_TermOfAgreement" name="TermOfAgreement" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesAvailableForGrantGrantsInPeriodGross" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesAvailableForGrantGrantsInPeriodGross" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_ProceedsFromIssuanceOfEmployeeStockPlans" name="ProceedsFromIssuanceOfEmployeeStockPlans" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fdmt_IncreasedAggregateMilestonePayments" name="IncreasedAggregateMilestonePayments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_AmountsPaidNonRefundableLicenseFees" name="AmountsPaidNonRefundableLicenseFees" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_UniQureBiopharmaBVMember" name="UniQureBiopharmaBVMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_ResearchAndCollaborationArrangementsAbstract" name="ResearchAndCollaborationArrangementsAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_CollaborationArrangementsUpfrontPaymentReceived" name="CollaborationArrangementsUpfrontPaymentReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_CommonStockWarrantsTextBlock" name="CommonStockWarrantsTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_TwoThousandTwentyOneFollowOnPublicOfferingMember" name="TwoThousandTwentyOneFollowOnPublicOfferingMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_CustomerBMember" name="CustomerBMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_AccruedClinicalAndPreclinicalStudyCosts" name="AccruedClinicalAndPreclinicalStudyCosts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_AnnualRoyalty" name="AnnualRoyalty" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_CustomerCMember" name="CustomerCMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fdmt_CollaborativeArrangementsSpecialTerm" name="CollaborativeArrangementsSpecialTerm" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_CollaborativeArrangementAchievedMilestones" name="CollaborativeArrangementAchievedMilestones" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_ShareBasedCompensationArrangementByShareBasedPaymentAwardExercisePriceAsPercentageOfFairMarketValueMinimum" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardExercisePriceAsPercentageOfFairMarketValueMinimum" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_UpfrontConsiderationPayment" name="UpfrontConsiderationPayment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fdmt_ContingentPaymentsDevelopmentMilestones" name="ContingentPaymentsDevelopmentMilestones" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_CollaborativeArrangementTransactionPriceAdjustment" name="CollaborativeArrangementTransactionPriceAdjustment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fdmt_AgreementTerminatedMonthAndYear" name="AgreementTerminatedMonthAndYear" type="xbrli:gYearMonthItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fdmt_CollaborativeArrangementInitialResearchTerm" name="CollaborativeArrangementInitialResearchTerm" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
</xsd:schema>
