<?xml version="1.0" encoding="utf-8"?>
<Return xmlns="http://www.irs.gov/efile" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" returnVersion="2023v5.0">
  <ReturnHeader binaryAttachmentCnt="0">
    <ReturnTs>2024-05-13T07:20:14-04:00</ReturnTs>
    <TaxPeriodEndDt>2023-12-31</TaxPeriodEndDt>
    <PreparerFirmGrp>
      <PreparerFirmEIN>204917696</PreparerFirmEIN>
      <PreparerFirmName>
        <BusinessNameLine1Txt>THE CLEVELAND GROUP</BusinessNameLine1Txt>
      </PreparerFirmName>
      <PreparerUSAddress>
        <AddressLine1Txt>3740 EXECUTIVE CENTER DR STE 200</AddressLine1Txt>
        <CityNm>MARTINEZ</CityNm>
        <StateAbbreviationCd>GA</StateAbbreviationCd>
        <ZIPCd>309072360</ZIPCd>
      </PreparerUSAddress>
    </PreparerFirmGrp>
    <ReturnTypeCd>990EZ</ReturnTypeCd>
    <TaxPeriodBeginDt>2023-01-01</TaxPeriodBeginDt>
    <Filer>
      <EIN>463884135</EIN>
      <BusinessName>
        <BusinessNameLine1Txt>MOWAT-WILSON SYNDROME FOUNDATION</BusinessNameLine1Txt>
      </BusinessName>
      <BusinessNameControlTxt>MOWA</BusinessNameControlTxt>
      <PhoneNum>7026585391</PhoneNum>
      <USAddress>
        <AddressLine1Txt>4009 TYLER WILLIAM LANE</AddressLine1Txt>
        <CityNm>LAS VEGAS</CityNm>
        <StateAbbreviationCd>NV</StateAbbreviationCd>
        <ZIPCd>891302628</ZIPCd>
      </USAddress>
    </Filer>
    <BusinessOfficerGrp>
      <PersonNm>KAREN KEY</PersonNm>
      <PersonTitleTxt>TREASURER</PersonTitleTxt>
      <PhoneNum>7026585391</PhoneNum>
      <SignatureDt>2024-05-13</SignatureDt>
      <DiscussWithPaidPreparerInd>true</DiscussWithPaidPreparerInd>
    </BusinessOfficerGrp>
    <SigningOfficerGrp>
      <PersonFullName>
        <PersonFirstNm>KAREN</PersonFirstNm>
        <PersonLastNm>KEY</PersonLastNm>
      </PersonFullName>
      <SSN>999009999</SSN>
    </SigningOfficerGrp>
    <IRSResponsiblePrtyInfoCurrInd>true</IRSResponsiblePrtyInfoCurrInd>
    <PreparerPersonGrp>
      <PreparerPersonNm>JOANNE FREY</PreparerPersonNm>
      <PTIN>P00969986</PTIN>
      <PhoneNum>7062882800</PhoneNum>
      <PreparationDt>2024-05-13</PreparationDt>
    </PreparerPersonGrp>
    <TaxYr>2023</TaxYr>
    <BuildTS>2023-04-26 12:10:37Z</BuildTS>
  </ReturnHeader>
  <ReturnData documentCnt="5">
    <IRS990EZ documentId="RetDoc2" referenceDocumentId="RetDoc4">
      <MethodOfAccountingCashInd>X</MethodOfAccountingCashInd>
      <WebsiteAddressTxt>WWW.MOWAT-WILSON.ORG</WebsiteAddressTxt>
      <Organization501c3Ind referenceDocumentId="RetDoc5">X</Organization501c3Ind>
      <TypeOfOrganizationCorpInd>X</TypeOfOrganizationCorpInd>
      <GrossReceiptsAmt>197568</GrossReceiptsAmt>
      <InfoInScheduleOPartIInd>X</InfoInScheduleOPartIInd>
      <ContributionsGiftsGrantsEtcAmt>134370</ContributionsGiftsGrantsEtcAmt>
      <FundraisingGrossIncomeAmt referenceDocumentId="RetDoc3">62691</FundraisingGrossIncomeAmt>
      <SpecialEventsDirectExpensesAmt>7548</SpecialEventsDirectExpensesAmt>
      <SpecialEventsNetIncomeLossAmt>55143</SpecialEventsNetIncomeLossAmt>
      <GrossSalesOfInventoryAmt>507</GrossSalesOfInventoryAmt>
      <GrossProfitLossSlsOfInvntryAmt>507</GrossProfitLossSlsOfInvntryAmt>
      <TotalRevenueAmt>190020</TotalRevenueAmt>
      <SalariesOtherCompEmplBnftAmt>4064</SalariesOtherCompEmplBnftAmt>
      <FeesAndOtherPymtToIndCntrctAmt>11998</FeesAndOtherPymtToIndCntrctAmt>
      <PrintingPublicationsPostageAmt>122</PrintingPublicationsPostageAmt>
      <OtherExpensesTotalAmt>44071</OtherExpensesTotalAmt>
      <TotalExpensesAmt>60255</TotalExpensesAmt>
      <ExcessOrDeficitForYearAmt>129765</ExcessOrDeficitForYearAmt>
      <NetAssetsOrFundBalancesBOYAmt>151281</NetAssetsOrFundBalancesBOYAmt>
      <NetAssetsOrFundBalancesEOYAmt>281046</NetAssetsOrFundBalancesEOYAmt>
      <CashSavingsAndInvestmentsGrp>
        <BOYAmt>151281</BOYAmt>
        <EOYAmt>281046</EOYAmt>
      </CashSavingsAndInvestmentsGrp>
      <Form990TotalAssetsGrp>
        <BOYAmt>151281</BOYAmt>
        <EOYAmt>281046</EOYAmt>
      </Form990TotalAssetsGrp>
      <NetAssetsOrFundBalancesGrp>
        <BOYAmt>151281</BOYAmt>
        <EOYAmt>281046</EOYAmt>
      </NetAssetsOrFundBalancesGrp>
      <InfoInScheduleOPartIIIInd>X</InfoInScheduleOPartIIIInd>
      <PrimaryExemptPurposeTxt>THE MISSION OF THE MOWAT-WILSON SYNDROME FOUNDATION IS TO ENHANCE THE LIVES OF PEOPLE AFFECTED BY MOWAT-WILSON SYNDROME BY PROVIDING FAMILY SUPPORT, RAISING AWARENESS, AND SUPPORTING RESEARCH AND EDUCATION.</PrimaryExemptPurposeTxt>
      <ProgramSrvcAccomplishmentGrp>
        <DescriptionProgramSrvcAccomTxt>PROGRAMS USED TO ENHANCE THE LIVES OF PEOPLE AFFECTED BY MOWAT-WILSON SYNDROME BY PROVIDING FAMILY SUPPORT, RAISING AWARENESS, AND SUPPORTING RESEARCH AND EDUCATION.</DescriptionProgramSrvcAccomTxt>
        <ProgramServiceExpensesAmt>33612</ProgramServiceExpensesAmt>
      </ProgramSrvcAccomplishmentGrp>
      <TotalProgramServiceExpensesAmt>33612</TotalProgramServiceExpensesAmt>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>DEBORAH CURRY</PersonNm>
        <TitleTxt>VICE-PRESIDE</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>20.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>PAUL JACOBI</PersonNm>
        <TitleTxt>PRESIDENT</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>15.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>KAREN KEY</PersonNm>
        <TitleTxt>TREASURER</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>10.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>CATHERINE TOLMAN</PersonNm>
        <TitleTxt>SECRETARY</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>2.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>DR ADERO C E ALLISON PHD</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>9.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>LAURA CHRYSOSTOMO</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>2.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>KATIE FINEBERG</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>1.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>ADAM BATCHELOR</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>2.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>JOHN SELL</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>1.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>FELISHA NORRINGTON</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>4.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>SANDOR PISZAR</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>2.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>AL TRIUNFO</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>5.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <ActivitiesNotPreviouslyRptInd>false</ActivitiesNotPreviouslyRptInd>
      <ChgMadeToOrgnzngDocNotRptInd>false</ChgMadeToOrgnzngDocNotRptInd>
      <OrganizationHadUBIInd>false</OrganizationHadUBIInd>
      <SubjectToProxyTaxInd>false</SubjectToProxyTaxInd>
      <OrganizationDissolvedEtcInd>false</OrganizationDissolvedEtcInd>
      <Form1120PolFiledInd>false</Form1120PolFiledInd>
      <MadeLoansToFromOfficersInd>false</MadeLoansToFromOfficersInd>
      <EngagedInExcessBenefitTransInd>false</EngagedInExcessBenefitTransInd>
      <ProhibitedTaxShelterTransInd>false</ProhibitedTaxShelterTransInd>
      <BooksInCareOfDetail>
        <PersonNm>KAREN KEY</PersonNm>
        <USAddress>
          <AddressLine1Txt>4009 TYLER WILLIAM LN</AddressLine1Txt>
          <CityNm>LAS VEGAS</CityNm>
          <StateAbbreviationCd>NV</StateAbbreviationCd>
          <ZIPCd>891302628</ZIPCd>
        </USAddress>
        <PhoneNum>7026585391</PhoneNum>
      </BooksInCareOfDetail>
      <ForeignFinancialAccountInd>false</ForeignFinancialAccountInd>
      <ForeignOfficeInd>false</ForeignOfficeInd>
      <DonorAdvisedFndsInd>false</DonorAdvisedFndsInd>
      <OperateHospitalInd>false</OperateHospitalInd>
      <TanningServicesProvidedInd>false</TanningServicesProvidedInd>
      <RelatedOrganizationCtrlEntInd>false</RelatedOrganizationCtrlEntInd>
      <TransactionWithControlEntInd>false</TransactionWithControlEntInd>
      <PoliticalCampaignActyInd>false</PoliticalCampaignActyInd>
      <LobbyingActivitiesInd>false</LobbyingActivitiesInd>
      <SchoolOperatingInd>false</SchoolOperatingInd>
      <TrnsfrExmptNonChrtblRltdOrgInd>false</TrnsfrExmptNonChrtblRltdOrgInd>
      <PartVIOfCompOfHghstPdEmplTxt>NONE</PartVIOfCompOfHghstPdEmplTxt>
      <PartVIHghstPdCntrctProfSrvcTxt>NONE</PartVIHghstPdCntrctProfSrvcTxt>
      <FiledScheduleAInd>true</FiledScheduleAInd>
    </IRS990EZ>
    <IRS990ScheduleA documentId="RetDoc5">
      <PubliclySupportedOrg509a2Ind>X</PubliclySupportedOrg509a2Ind>
      <GiftsGrantsContrisRcvd509Grp>
        <CurrentTaxYearMinus4YearsAmt>113136</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>138885</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>83596</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>121876</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>134370</CurrentTaxYearAmt>
        <TotalAmt>591863</TotalAmt>
      </GiftsGrantsContrisRcvd509Grp>
      <GrossReceiptsAdmissionsGrp>
        <CurrentTaxYearMinus2YearsAmt>4640</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>45</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>63198</CurrentTaxYearAmt>
        <TotalAmt>67883</TotalAmt>
      </GrossReceiptsAdmissionsGrp>
      <Total509Grp>
        <CurrentTaxYearMinus4YearsAmt>113136</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>138885</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>88236</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>121921</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>197568</CurrentTaxYearAmt>
        <TotalAmt>659746</TotalAmt>
      </Total509Grp>
      <PublicSupportTotal509Amt>659746</PublicSupportTotal509Amt>
      <TotalSupportCalendarYearGrp>
        <CurrentTaxYearMinus4YearsAmt>113136</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>138885</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>88236</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>121921</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>197568</CurrentTaxYearAmt>
        <TotalAmt>659746</TotalAmt>
      </TotalSupportCalendarYearGrp>
      <PublicSupportCY509Pct>1.00000</PublicSupportCY509Pct>
      <PublicSupportPY509Pct>1.00000</PublicSupportPY509Pct>
      <InvestmentIncomeCYPct>0.00000</InvestmentIncomeCYPct>
      <InvestmentIncomePYPct>0.00000</InvestmentIncomePYPct>
      <ThirtyThrPctSuprtTestsCY509Ind>X</ThirtyThrPctSuprtTestsCY509Ind>
    </IRS990ScheduleA>
    <IRS990ScheduleB documentId="RetDoc1">
      <ContributorInformationGrp>
        <ContributorNum>RESTRICTED</ContributorNum>
        <ContributorBusinessName>
          <BusinessNameLine1>RESTRICTED</BusinessNameLine1>
        </ContributorBusinessName>
        <ContributorUSAddress>
          <AddressLine1>RESTRICTED</AddressLine1>
          <AddressLine2>RESTRICTED</AddressLine2>
          <City>RESTRICTED</City>
          <State>RESTRICTED</State>
          <ZIPCode>RESTRICTED</ZIPCode>
        </ContributorUSAddress>
        <TotalContributionsAmt>RESTRICTED</TotalContributionsAmt>
      </ContributorInformationGrp>
    </IRS990ScheduleB>
    <IRS990ScheduleG documentId="RetDoc3">
      <FundraisingEventInformationGrp>
        <Event1Nm>LOGAN'S FREE TH</Event1Nm>
        <GrossReceiptsEvent1Amt>29258</GrossReceiptsEvent1Amt>
        <GrossRevenueEvent1Amt>29258</GrossRevenueEvent1Amt>
        <OtherDirectExpensesEvent1Amt>5541</OtherDirectExpensesEvent1Amt>
        <Event2Nm>ULTRA NIAGARA -</Event2Nm>
        <GrossReceiptsEvent2Amt>18562</GrossReceiptsEvent2Amt>
        <GrossRevenueEvent2Amt>18562</GrossRevenueEvent2Amt>
        <FoodAndBeverageEvent2Amt>381</FoodAndBeverageEvent2Amt>
        <OtherDirectExpensesEvent2Amt>1285</OtherDirectExpensesEvent2Amt>
        <OtherEventsTotalCnt>1</OtherEventsTotalCnt>
        <GrossReceiptsOtherEventsAmt>11694</GrossReceiptsOtherEventsAmt>
        <GrossRevenueOtherEventsAmt>11694</GrossRevenueOtherEventsAmt>
        <OthDirectExpnssOtherEventsAmt>262</OthDirectExpnssOtherEventsAmt>
        <GrossReceiptsTotalAmt>59514</GrossReceiptsTotalAmt>
        <GrossRevenueTotalEventsAmt>59514</GrossRevenueTotalEventsAmt>
        <FoodAndBeverageTotalEventsAmt>381</FoodAndBeverageTotalEventsAmt>
        <OthDirectExpnssTotalEventsAmt>7088</OthDirectExpnssTotalEventsAmt>
        <DirectExpenseSummaryEventsAmt>7469</DirectExpenseSummaryEventsAmt>
        <NetIncomeSummaryAmt>52045</NetIncomeSummaryAmt>
      </FundraisingEventInformationGrp>
    </IRS990ScheduleG>
    <IRS990ScheduleO documentId="RetDoc4">
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990-EZ, PART I, LINE 16</FormAndLineReferenceDesc>
        <ExplanationTxt>EXPENSES TRAVEL 582 INSURANCE 660 BANK &amp; SERVICE CHARGES 1,380 DUES &amp; SUBSCRIPTIONS 200 MISCELLANEOUS 138 MANAGEMENT CONTRACTS 24,000 FILING AND REGISTRATION 8,565 MEALS, CATERING, FOOD 5,411 PLATFORM SUBSCRIPTIONS 3,135 TOTAL 44,071</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990-EZ, PART III</FormAndLineReferenceDesc>
        <ExplanationTxt>THE MISSION OF THE MOWAT-WILSON SYNDROME FOUNDATION IS TO ENHANCE THE LIVES OF PEOPLE AFFECTED BY MOWAT-WILSON SYNDROME BY PROVIDING FAMILY SUPPORT, RAISING AWARENESS, AND SUPPORTING RESEARCH AND EDUCATION.</ExplanationTxt>
      </SupplementalInformationDetail>
    </IRS990ScheduleO>
  </ReturnData>
</Return>
