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    <IdentifierDoi>10.3205/26rhk157</IdentifierDoi>
    <IdentifierUrn>urn:nbn:de:0183-26rhk1575</IdentifierUrn>
    <ArticleType>Meeting Abstract</ArticleType>
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      <Title language="en">A rare case of aneurysmal subarachnoid hemorrhage in pediatric deficiency of adenosine deaminase 2</Title>
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        <PersonNames>
          <Lastname>Oestreich</Lastname>
          <LastnameHeading>Oestreich</LastnameHeading>
          <Firstname>Marc-Alexander</Firstname>
          <Initials>MA</Initials>
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        <Address>
          <Affiliation>Inselspital Bern, Universit&#228;tsklinik f&#252;r Kinderheilkunde, P&#228;diatrische Rheumatologie, Bern, Schweiz</Affiliation>
          <Affiliation>Universit&#228;ts-Kinderspital Beider Basel UKBB, P&#228;diatrische Rheumatologie, Basel, Schweiz</Affiliation>
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      <Creator>
        <PersonNames>
          <Lastname>Tenbrock</Lastname>
          <LastnameHeading>Tenbrock</LastnameHeading>
          <Firstname>Klaus</Firstname>
          <Initials>K</Initials>
        </PersonNames>
        <Address>
          <Affiliation>Universit&#228;tsklinikum Aachen, Universit&#228;tsklinik f&#252;r Kinderheilkunde, P&#228;diatrische Rheumatologie, Aachen, Deutschland</Affiliation>
          <Affiliation>Inselspital Bern, Universit&#228;tsklinik f&#252;r Kinderheilkunde, P&#228;diatrische Rheumatologie, Bern, Schweiz</Affiliation>
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          <Corporatename>German Medical Science GMS Publishing House</Corporatename>
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        <Address>D&#252;sseldorf</Address>
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    <SubjectGroup>
      <SubjectheadingDDB>610</SubjectheadingDDB>
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    <DatePublishedList>
      <DatePublished>20260909</DatePublished>
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    <Language>engl</Language>
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      <AltText language="en">This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License.</AltText>
      <AltText language="de">Dieser Artikel ist ein Open-Access-Artikel und steht unter den Lizenzbedingungen der Creative Commons Attribution 4.0 License (Namensnennung).</AltText>
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        <MeetingId>M0656</MeetingId>
        <MeetingSequence>157</MeetingSequence>
        <MeetingCorporation>Deutsche Gesellschaft f&#252;r Rheumatologie</MeetingCorporation>
        <MeetingCorporation>Deutsche Gesellschaft f&#252;r Orthop&#228;dische Rheumatologie</MeetingCorporation>
        <MeetingCorporation>Gesellschaft f&#252;r Kinder- und Jugendrheumatologie</MeetingCorporation>
        <MeetingName>54. Kongress der Deutschen Gesellschaft f&#252;r Rheumatologie und Klinische Immunologie (DGRh), 36. Jahrestagung der Gesellschaft f&#252;r Kinder- und Jugendrheumatologie (GKJR), 40. Jahrestagung der Deutschen Gesellschaft f&#252;r Orthop&#228;dische Rheumatologie (DGORh)</MeetingName>
        <MeetingTitle>Deutscher Rheumatologiekongress 2026</MeetingTitle>
        <MeetingSession>Kinderrheumatologie</MeetingSession>
        <MeetingCity>Leipzig</MeetingCity>
        <MeetingDate>
          <DateFrom>20260909</DateFrom>
          <DateTo>20260912</DateTo>
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      <MainHeadline>Text</MainHeadline><Pgraph><Mark1>Introduction: </Mark1>Deficiency of adenosine deaminase 2 (DADA2) is a rare monogenic autosomal recessive disorder caused by variations in the ADA2 gene&#39;s loss of function and exhibits a wide range of clinical symptoms including livedoid rash, vascular manifestations, hematological abnormalities, and systemic inflammation. We present a case of a 9-year-old DADA2-patient with recurrent stroke and extensive cortical and cervical spinal cord ischemia due to aneurysmal subarachnoid hemorrhage.</Pgraph><Pgraph><Mark1>Results: </Mark1>A 7-year-old male patient from a kurdish consanguineous family was referred to our pediatric rheumatology outpatient clinic with suspected autoinflammatory disease. Since the age of two, he repeatedly experienced diffuse limb pain, especially during the cold season, accompanied by livedo and fever. Livedoid skin lesions were clearly visible during episodes of pain and after exposure to cold but no other symptoms. One year later, after a loss-to-follow-up, the patient presented to our pediatric emergency department with a hypertensive crisis, posterior reversible encephalopathy syndrome, and peroneal nerve palsy. Genetic analysis revealed compound heterozygosity for two pathogenic missense variants in the ADA2 gene and the initial treatment (anakinra) therapy was switched to tumor necrosis factor (TNF) blockage with adalimumab. The following day, he was hospitalized with a frontal lobe infarction in the precentral gyrus. He slowly recovered from the stroke. However, due to the series of events, the family decided against further anti-TNF therapy, and he received canakinumab. Six months later, he presented with extensive cortical and cervical spinal cord ischemia resulting from subarachnoid hemorrhage. Digital subtraction angiography revealed multiple small, previously unknown, intracranial aneurysms in the posterior circulation and the anterior spinal artery, which could not be treated surgically or endovascularly. He received conservative management but suffered numerous complications including intracranial vasospasms and further ischemic strokes. With intensive neurological rehabilitation, he has made significant neurological progress in recent months.</Pgraph><Pgraph><Mark1>Conclusion: </Mark1>Aneurysmal subarachnoid hemorrhage in pediatric DADA2 is rare. Since small and&#47;or peripheral aneurysms can be missed by standard cranial MRI, a low-threshold for additional diagnostic workup is recommended.</Pgraph></TextBlock>
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