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  <xs:element name="BusinessAcquisitionEquityInterestIssuedOrIssuableTradingDayPeriod" id="ptct_BusinessAcquisitionEquityInterestIssuedOrIssuableTradingDayPeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element id="ptct_ContingentLiabilityMilestonePotentialAchievementsPriorityReviewVoucherAmountNetofCancellationandForfeiture" name="ContingentLiabilityMilestonePotentialAchievementsPriorityReviewVoucherAmountNetofCancellationandForfeiture" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <xs:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsIntrinsicValueRollForward" id="ptct_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsIntrinsicValueRollForward" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xs:element name="SettlementOfDeferredAndContingentConsideration" id="ptct_SettlementOfDeferredAndContingentConsideration" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="duration" />
  <xs:element name="NumberOfOperatingLeases" id="ptct_NumberOfOperatingLeases" type="xbrli:integerItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="instant" />
  <xs:element name="ProbabilityofSuccessMember" id="ptct_ProbabilityofSuccessMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xs:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorizedAnnualIncreaseNumber" id="ptct_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorizedAnnualIncreaseNumber" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xs:element name="RoyaltyPurchaseAgreementPaymentMaximum" id="ptct_RoyaltyPurchaseAgreementPaymentMaximum" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <element id="ptct_ContingentLiabilityCancellationAndForfeitureMilestonePotentialAchievementsPriorityReviewVoucherAmount" name="ContingentLiabilityCancellationAndForfeitureMilestonePotentialAchievementsPriorityReviewVoucherAmount" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <xs:element name="HopewellCampusMember" id="ptct_HopewellCampusMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <element id="ptct_AssetAcquisitionNetSalesMilestone" name="AssetAcquisitionNetSalesMilestone" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_AssetAcquisitionInProcessResearchAndDevelopment" name="AssetAcquisitionInProcessResearchAndDevelopment" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <xs:element name="ConvertibleSeniorNotes3.0PercentDue2022Member" id="ptct_ConvertibleSeniorNotes3.0PercentDue2022Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xs:element name="RoyaltyPurchaseAgreementTerminationPeriod" id="ptct_RoyaltyPurchaseAgreementTerminationPeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xs:element name="PaymentOfFinanceLeasePrincipal" id="ptct_PaymentOfFinanceLeasePrincipal" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <element id="ptct_ContingentLiabilityCancellationAndForfeiture" name="ContingentLiabilityCancellationAndForfeiture" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <xs:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorizedAnnualIncreaseAsPercentageOfStockOutstanding" id="ptct_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorizedAnnualIncreaseAsPercentageOfStockOutstanding" type="num:percentItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xs:element name="DebtInstrumentConvertibleThresholdConsecutiveTradingDayPeriod" id="ptct_DebtInstrumentConvertibleThresholdConsecutiveTradingDayPeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xs:element name="BusinessCombinationConsiderationLiabilityDeferredConsiderationPayableCurrent" id="ptct_BusinessCombinationConsiderationLiabilityDeferredConsiderationPayableCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="instant" />
  <xs:element name="PaymentsForAssetAcquisitionsNetAssets" id="ptct_PaymentsForAssetAcquisitionsNetAssets" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xs:element name="AdjustmentsToAdditionalPaidInCapitalReceivableFromInvestor" id="ptct_AdjustmentsToAdditionalPaidInCapitalReceivableFromInvestor" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <element id="ptct_Percentageofnetproductsales" name="Percentageofnetproductsales" nillable="true" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <xs:element name="BridgewaterMember" id="ptct_BridgewaterMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <element id="ptct_DevelopmentMilestonePaymentObligationsCancellationAndForfeiture" name="DevelopmentMilestonePaymentObligationsCancellationAndForfeiture" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <xs:element name="ContingentLiabilityMilestonePotentialAchievementsPriorityReviewVoucherAmount" id="ptct_ContingentLiabilityMilestonePotentialAchievementsPriorityReviewVoucherAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="duration" />
  <element id="ptct_LesseeOperatingLeaseLiabilityPaymentsDueYearFiveandThereafter" name="LesseeOperatingLeaseLiabilityPaymentsDueYearFiveandThereafter" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <xs:element name="DevelopmentMilestonePaymentObligationsDueOnSecondAnniversaryYearOfMergerClosing" id="ptct_DevelopmentMilestonePaymentObligationsDueOnSecondAnniversaryYearOfMergerClosing" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="instant" />
  <xs:element name="AssignedRoyaltyPaymentPercentage" id="ptct_AssignedRoyaltyPaymentPercentage" type="num:percentItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="instant" />
  <xs:element name="DepositsAndOtherAssetsNoncurrent" id="ptct_DepositsAndOtherAssetsNoncurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <xs:element name="RightsExchangeAgreementMember" id="ptct_RightsExchangeAgreementMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xs:element name="InventoriesAndCostOfProductSalesPolicyTextBlock" id="ptct_InventoriesAndCostOfProductSalesPolicyTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xs:element name="Termforletterofcredit" id="ptct_Termforletterofcredit" type="xbrli:durationItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xs:element name="UpfrontLicensingFee" id="ptct_UpfrontLicensingFee" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <element id="ptct_DevelopmentMilestonePaymentObligationsNetofCancellationandForfeiture" name="DevelopmentMilestonePaymentObligationsNetofCancellationandForfeiture" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <xs:element name="BusinessAcquisitionNumeratorForCalculationOfNumberOfSharesOfEquityInterestsIssuedToAcquireEntity" id="ptct_BusinessAcquisitionNumeratorForCalculationOfNumberOfSharesOfEquityInterestsIssuedToAcquireEntity" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="instant" />
  <xs:element name="MilestoneAxis" id="ptct_MilestoneAxis" type="xbrli:stringItemType" substitutionGroup="xbrldt:dimensionItem" abstract="true" nillable="true" xbrli:periodType="duration" />
  <element id="ptct_MilestonePotentialAchievementsRegulatoryApproval" name="MilestonePotentialAchievementsRegulatoryApproval" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <xs:element name="HopewellNewBuildingMember" id="ptct_HopewellNewBuildingMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xs:element name="DebtInstrumentAdditionalAmountAvailableForRepurchase" id="ptct_DebtInstrumentAdditionalAmountAvailableForRepurchase" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="duration" />
  <element id="ptct_SharestoissueunderRightsExchangeAgreement" name="SharestoissueunderRightsExchangeAgreement" nillable="true" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xmlns="http://www.w3.org/2001/XMLSchema" />
  <xs:element name="RestrictedStockAndRestrictedStockUnitsMember" id="ptct_RestrictedStockAndRestrictedStockUnitsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xs:element name="MarathonPharmaceuticalsLLCMember" id="ptct_MarathonPharmaceuticalsLLCMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xs:element name="AvailableForSaleSecuritiesDebtMaturitiesOverOneYearFairValue" id="ptct_AvailableForSaleSecuritiesDebtMaturitiesOverOneYearFairValue" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <xs:element name="AccruedConsultingAndContractedResearchCurrent" id="ptct_AccruedConsultingAndContractedResearchCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="instant" />
  <xs:element name="DebtInstrumentConversionPeriodOnOrAfterAugust202018Member" id="ptct_DebtInstrumentConversionPeriodOnOrAfterAugust202018Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xs:element name="DebtInstrumentInterestPaymentPeriod" id="ptct_DebtInstrumentInterestPaymentPeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xs:element name="MassBioMember" id="ptct_MassBioMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xs:element name="StockIncentivePlan2013Member" id="ptct_StockIncentivePlan2013Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <element id="ptct_RevenueRecognitionMilestonePotentialAchievements" name="RevenueRecognitionMilestonePotentialAchievements" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <xs:element name="EquityAndLongTermIncentivePlan2009Member" id="ptct_EquityAndLongTermIncentivePlan2009Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xs:element name="ScheduleOfInterestExpenseRecognizedRelatedToConvertibleDebtTableTextBlock" id="ptct_ScheduleOfInterestExpenseRecognizedRelatedToConvertibleDebtTableTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xs:element name="MidCapFinancialTrustMember" id="ptct_MidCapFinancialTrustMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xs:element name="DebtInstrumentFloorInterestRate" id="ptct_DebtInstrumentFloorInterestRate" type="num:percentItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="instant" />
  <xs:element name="StockAppreciationRightsLiabilityOutstanding" id="ptct_StockAppreciationRightsLiabilityOutstanding" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="instant" />
  <xs:element name="FiniteLivedIntangibleAssetsAmortizationExpenseYearFiveAndThereafter" id="ptct_FiniteLivedIntangibleAssetsAmortizationExpenseYearFiveAndThereafter" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <xs:element name="AssignedRoyaltyPaymentRetainedPercentage" id="ptct_AssignedRoyaltyPaymentRetainedPercentage" type="num:percentItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="instant" />
  <xs:element name="ResearchAndDevelopmentEventMilestonesMember" id="ptct_ResearchAndDevelopmentEventMilestonesMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xs:element name="FifthAnniversaryMember" id="ptct_FifthAnniversaryMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xs:element name="DebtInstrumentConvertibleThresholdBusinessDays" id="ptct_DebtInstrumentConvertibleThresholdBusinessDays" type="xbrli:durationItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xs:element name="CensaMember" id="ptct_CensaMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
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  <element id="ptct_SalesAllowanceAndOtherRelatedCosts" name="SalesAllowanceAndOtherRelatedCosts" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <xs:element name="LineOfCreditFacilityTerminationAndExitFees" id="ptct_LineOfCreditFacilityTerminationAndExitFees" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xs:element name="Equity2009AndLongTermIncentivePlanAndStockIncentivePlan2013Member" id="ptct_Equity2009AndLongTermIncentivePlanAndStockIncentivePlan2013Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xs:element name="MountainviewMember" id="ptct_MountainviewMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xs:element name="ContingentLiabilityMilestonePotentialAchievementsNetSalesMilestone" id="ptct_ContingentLiabilityMilestonePotentialAchievementsNetSalesMilestone" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="instant" />
  <xs:element name="AgilisMember" id="ptct_AgilisMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
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  <xs:element name="ConvertibleInstrumentsPrincipalAndUnpaidInterestPayableUponEventsOfDefault" id="ptct_ConvertibleInstrumentsPrincipalAndUnpaidInterestPayableUponEventsOfDefault" type="num:percentItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xs:element name="EmflazaassetacquisitionMember" id="ptct_EmflazaassetacquisitionMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xs:element name="LiabilityNetSalesMilestonesandRoyaltiesMember" id="ptct_LiabilityNetSalesMilestonesandRoyaltiesMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <element id="ptct_CostofGoodsandServiceExcludingAmortizationOfIntangibleAssets" name="CostofGoodsandServiceExcludingAmortizationOfIntangibleAssets" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <xs:element name="PercentageofSalesforRoyaltiesMember" id="ptct_PercentageofSalesforRoyaltiesMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xs:element name="DevelopmentandRegulatoryMilestoneMember" id="ptct_DevelopmentandRegulatoryMilestoneMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xs:element name="Numberofdistributors" id="ptct_Numberofdistributors" type="xbrli:integerItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xs:element name="PercentOfMarketRate" id="ptct_PercentOfMarketRate" type="num:percentItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="instant" />
  <xs:element name="DebtInstrumentConvertibleThresholdSalePriceOfCommonStockConversionRateProductPercentageMaximum" id="ptct_DebtInstrumentConvertibleThresholdSalePriceOfCommonStockConversionRateProductPercentageMaximum" type="num:percentItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="instant" />
  <xs:element name="EmployeeStockPurchasePlanVotingPercentageLimitPercent" id="ptct_EmployeeStockPurchasePlanVotingPercentageLimitPercent" type="num:percentItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xs:element name="MilestoneDomain" id="ptct_MilestoneDomain" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <element id="ptct_AssetAcquisitionResearchAndDevelopmentExpense" name="AssetAcquisitionResearchAndDevelopmentExpense" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <xs:element name="PaymentsForAssetAcquisitionsUpfrontPayment" id="ptct_PaymentsForAssetAcquisitionsUpfrontPayment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xs:element name="MinimumPercentageOfDebtPrincipalAmountByInstrumentHolders" id="ptct_MinimumPercentageOfDebtPrincipalAmountByInstrumentHolders" type="num:percentItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element id="ptct_AssetAcquisitionDevelopmentAndRegulatoryMilestones" name="AssetAcquisitionDevelopmentAndRegulatoryMilestones" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_PaymentsOnDeferredConsiderationObligation" name="PaymentsOnDeferredConsiderationObligation" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <xs:element name="GrantAndCollaborationMember" id="ptct_GrantAndCollaborationMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xs:element name="BusinessCombinationConsiderationLiabilityDeferredConsiderationPayable" id="ptct_BusinessCombinationConsiderationLiabilityDeferredConsiderationPayable" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="instant" />
  <element id="ptct_Numberofterms" name="Numberofterms" nillable="true" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xmlns="http://www.w3.org/2001/XMLSchema" />
  <xs:element name="LiabilityDevelopmentandRegulatoryMilestoneMember" id="ptct_LiabilityDevelopmentandRegulatoryMilestoneMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xs:element name="SalesMilestonesMember" id="ptct_SalesMilestonesMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <element id="ptct_AssetAcquisitionInitialMilestone" name="AssetAcquisitionInitialMilestone" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_AssetAcquisitionTransactionCosts" name="AssetAcquisitionTransactionCosts" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <xs:element name="LoanAdvance" id="ptct_LoanAdvance" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <xs:element name="NetDeferredTaxLiabilitiesConvertibleDebtInstruments" id="ptct_NetDeferredTaxLiabilitiesConvertibleDebtInstruments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="instant" />
  <element id="ptct_StockIssuedDuringPeriodValueExchangeRights" name="StockIssuedDuringPeriodValueExchangeRights" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_ContingentLiabilityMilestonePotentialAchievementsProductSalesPercentage" name="ContingentLiabilityMilestonePotentialAchievementsProductSalesPercentage" nillable="true" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xmlns="http://www.w3.org/2001/XMLSchema" />
  <xs:element name="WellcomeTrustLimitedMember" id="ptct_WellcomeTrustLimitedMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xs:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorizedSharesSubjectToOutstandingAwards" id="ptct_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorizedSharesSubjectToOutstandingAwards" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="instant" />
  <xs:element name="AkceaMember" id="ptct_AkceaMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <element id="ptct_PropertyPlantAndEquipmentUsefulLifeTableTextBlock" name="PropertyPlantAndEquipmentUsefulLifeTableTextBlock" nillable="true" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_DevelopmentMilestonePaymentObligations" name="DevelopmentMilestonePaymentObligations" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoptionVariableConsideration" name="CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoptionVariableConsideration" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_DeferredResearchAndDevelopmentCosts" name="DeferredResearchAndDevelopmentCosts" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_ComputerEquipmentAndSoftwareMember" name="ComputerEquipmentAndSoftwareMember" nillable="true" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_FurnitureFixturesAndLabEquipmentMember" name="FurnitureFixturesAndLabEquipmentMember" nillable="true" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedOtherAssets" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedOtherAssets" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedCurrentLiabilitiesAccountsPayableAndAccruedExpenses" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedCurrentLiabilitiesAccountsPayableAndAccruedExpenses" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredIncomeTaxes" name="BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredIncomeTaxes" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentNetAssets" name="BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentNetAssets" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentAssets" name="BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentAssets" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_InducementGrantPlanMember" name="InducementGrantPlanMember" nillable="true" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantedExercisePriceAsPercentageOfFairMarketValueOfCommonStock" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantedExercisePriceAsPercentageOfFairMarketValueOfCommonStock" nillable="true" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantedToStockholdersWithSpecifiedOwnershipPercentageExercisePriceAsPercentageOfFairMarketValueOfCommonStock" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantedToStockholdersWithSpecifiedOwnershipPercentageExercisePriceAsPercentageOfFairMarketValueOfCommonStock" nillable="true" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_ShareBasedCompensationArrangementByShareBasedPaymentAwardStockholdersSpecifiedOwnershipPercentage" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardStockholdersSpecifiedOwnershipPercentage" nillable="true" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePrice" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePrice" nillable="true" type="num:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_RocheAndSmaFoundationMember" name="RocheAndSmaFoundationMember" nillable="true" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_CollaborativeArrangementsNumberOfCompoundsInPreclinicalDevelopment" name="CollaborativeArrangementsNumberOfCompoundsInPreclinicalDevelopment" nillable="true" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_CollaborativeArrangementsNumberOfSignificantDeliverables" name="CollaborativeArrangementsNumberOfSignificantDeliverables" nillable="true" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_CollaborativeAgreementDeferredPaymentPerformancePeriod" name="CollaborativeAgreementDeferredPaymentPerformancePeriod" nillable="true" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_FirstFiveYearsMember" name="FirstFiveYearsMember" nillable="true" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_ThereAfterFiveYearsMember" name="ThereAfterFiveYearsMember" nillable="true" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_DeferredTaxAssetsOperatingLossCarryforwardsLimitedbyIRCSection382" name="DeferredTaxAssetsOperatingLossCarryforwardsLimitedbyIRCSection382" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_OperatingLossCarryforwardsForImmediateUse" name="OperatingLossCarryforwardsForImmediateUse" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_OperatingLossCarryforwardsInNextTwelveMonths" name="OperatingLossCarryforwardsInNextTwelveMonths" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_EffectiveIncomeTaxRateReconciliationPermanentDifferences" name="EffectiveIncomeTaxRateReconciliationPermanentDifferences" nillable="true" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_DeferredTaxAssetsAmortization" name="DeferredTaxAssetsAmortization" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_DeferredTaxAssetsTaxCreditFederal" name="DeferredTaxAssetsTaxCreditFederal" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_DeferredTaxAssetsTaxCreditState" name="DeferredTaxAssetsTaxCreditState" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_DeferredTaxAssetsDeferredExpenseCapitalizedResearchAndDevelopmentCosts" name="DeferredTaxAssetsDeferredExpenseCapitalizedResearchAndDevelopmentCosts" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_DeferredTaxLiabilitiesConvertibleDebt" name="DeferredTaxLiabilitiesConvertibleDebt" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_AssignedRoyaltyPaymentsMember" name="AssignedRoyaltyPaymentsMember" nillable="true" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_RoyaltyPurchaseAgreementMember" name="RoyaltyPurchaseAgreementMember" nillable="true" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_LiabilitySaleOfFutureRoyaltiesCurrent" name="LiabilitySaleOfFutureRoyaltiesCurrent" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_LiabilitySaleOfFutureRoyaltiesNoncurrent" name="LiabilitySaleOfFutureRoyaltiesNoncurrent" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_NoncashRoyaltyRevenueSaleOfFutureRoyalties" name="NoncashRoyaltyRevenueSaleOfFutureRoyalties" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_NoncashInterestExpenseLiabilityRelatedToSaleOfFutureRoyalties" name="NoncashInterestExpenseLiabilityRelatedToSaleOfFutureRoyalties" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_ProceedsFromSaleOfFutureRoyalties" name="ProceedsFromSaleOfFutureRoyalties" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_LesseeOperatingLeaseWrittenNotificationPeriodToTerminate" name="LesseeOperatingLeaseWrittenNotificationPeriodToTerminate" nillable="true" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_DevelopmentMilestoneObligationPaymentsMade" name="DevelopmentMilestoneObligationPaymentsMade" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_LiabilitySaleOfFutureRoyalties" name="LiabilitySaleOfFutureRoyalties" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_LiabilitySaleOfFutureRoyaltiesObligationIncurred" name="LiabilitySaleOfFutureRoyaltiesObligationIncurred" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_LiabilitySaleOfFutureRoyaltiesRoyaltyRevenuePayable" name="LiabilitySaleOfFutureRoyaltiesRoyaltyRevenuePayable" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_LiabilitySaleOfFutureRoyaltiesInterestExpense" name="LiabilitySaleOfFutureRoyaltiesInterestExpense" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_ProceedsFromMilestonePaymentsReceived" name="ProceedsFromMilestonePaymentsReceived" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_LiabilityForSaleOfFutureRoyaltiesPolicyTextBlock" name="LiabilityForSaleOfFutureRoyaltiesPolicyTextBlock" nillable="true" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_PaymentOfAccruedInterest" name="PaymentOfAccruedInterest" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_RepaymentsOfLinesOfCreditAggregatePayment" name="RepaymentsOfLinesOfCreditAggregatePayment" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_LeaseCostExcludingFinanceLeaseCosts" name="LeaseCostExcludingFinanceLeaseCosts" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_LiabilityForSaleOfFutureRoyaltiesTableTextBlock" name="LiabilityForSaleOfFutureRoyaltiesTableTextBlock" nillable="true" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_FinanceLeaseLiabilityPaymentsDueYearFiveAndAfter" name="FinanceLeaseLiabilityPaymentsDueYearFiveAndAfter" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_MachineryAndLabEquipmentMember" name="MachineryAndLabEquipmentMember" nillable="true" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_EffectiveIncomeTaxRateReconciliationChangeInUncertainTaxPositionsPercent" name="EffectiveIncomeTaxRateReconciliationChangeInUncertainTaxPositionsPercent" nillable="true" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_SaleOfStockOptionToPurchaseSharesNotExercised" name="SaleOfStockOptionToPurchaseSharesNotExercised" nillable="true" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_SaleOfStockOptionPeriodToPurchaseShares" name="SaleOfStockOptionPeriodToPurchaseShares" nillable="true" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_SaleOfStockRemainingSharesAvailableForSaleAggregateOfferingValue" name="SaleOfStockRemainingSharesAvailableForSaleAggregateOfferingValue" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_InducementStockIncentivePlan2020Member" name="InducementStockIncentivePlan2020Member" nillable="true" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_SalesRebatesCurrent" name="SalesRebatesCurrent" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_DebtInstrumentConversionPeriodOnOrAfterSeptember202023Member" name="DebtInstrumentConversionPeriodOnOrAfterSeptember202023Member" nillable="true" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_ConvertibleDebtInstrumentsRedemptions" name="ConvertibleDebtInstrumentsRedemptions" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_LesseeOperatingLeaseLiabilityToBePaidAfterYearTwo" name="LesseeOperatingLeaseLiabilityToBePaidAfterYearTwo" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_OperatingLossCarryforwardsUtilized" name="OperatingLossCarryforwardsUtilized" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_OperatingLossCarryforwardsLimitedByIrcSection382Utilized" name="OperatingLossCarryforwardsLimitedByIrcSection382Utilized" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_MeasurementInputStrikePriceMember" name="MeasurementInputStrikePriceMember" nillable="true" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_RightsExchangeSettlementMeasurementInput" name="RightsExchangeSettlementMeasurementInput" nillable="true" type="xbrli:decimalItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_RightsExchangeSettlementPotentialMilestonesValue" name="RightsExchangeSettlementPotentialMilestonesValue" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_AvailableForSaleDebtSecuritiesConversionPrice" name="AvailableForSaleDebtSecuritiesConversionPrice" nillable="true" type="num:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_TaxableIncomeBeforeNetOperatingLoss" name="TaxableIncomeBeforeNetOperatingLoss" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_PotentialMilestonePaymentsForfeitedByParticipatingRightholders" name="PotentialMilestonePaymentsForfeitedByParticipatingRightholders" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_LiabilityDevelopmentMilestoneMember" name="LiabilityDevelopmentMilestoneMember" nillable="true" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_LiabilityRegulatoryMilestoneMember" name="LiabilityRegulatoryMilestoneMember" nillable="true" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_GainLossOnSettlementOfMilestones" name="GainLossOnSettlementOfMilestones" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_GainLossRecognizedOnChangeInFairValueOnContingentConsiderationForfeited" name="GainLossRecognizedOnChangeInFairValueOnContingentConsiderationForfeited" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_LeaseDisclosureTextBlock" name="LeaseDisclosureTextBlock" nillable="true" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_LeaseBalanceSheetDisclosureTableTextBlock" name="LeaseBalanceSheetDisclosureTableTextBlock" nillable="true" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_LeaseSupplementalCashFlowDisclosureTableTextBlock" name="LeaseSupplementalCashFlowDisclosureTableTextBlock" nillable="true" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_SmaLicenseAgreementMember" name="SmaLicenseAgreementMember" nillable="true" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_DeferredPayrollTaxLiabilityCaresAct" name="DeferredPayrollTaxLiabilityCaresAct" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_StockAppreciationRightsMeasurementInput" name="StockAppreciationRightsMeasurementInput" nillable="true" type="xbrli:decimalItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="ptct_SettledValueOfMilestonePaymentsForfeitedByParticipatingRightholders" name="SettledValueOfMilestonePaymentsForfeitedByParticipatingRightholders" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
</xs:schema>
