{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,9,28]],"date-time":"2025-09-28T11:15:07Z","timestamp":1759058107770,"version":"3.40.5"},"reference-count":9,"publisher":"Wiley","license":[{"start":{"date-parts":[[2022,2,14]],"date-time":"2022-02-14T00:00:00Z","timestamp":1644796800000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Case Reports in Immunology"],"published-print":{"date-parts":[[2022,2,14]]},"abstract":"<jats:p>The availability of next-generation sequencing (NGS) helps to resolve many of the diagnostic odysseys. Common variable immunodeficiency disease (CVID) is an entity encompassing a heterogenous group of conditions with hypogammaglobulinemia, and it is a diagnosis of exclusion. In recent years, with the advances of molecular diagnostics, more and more patients have been reclassified with more defined entities after their genetic causes were found. Here, we reported a young man, who was managed as CVID since childhood, presenting with recurrent infection, hypogammaglobulinemia, and immune thrombocytopenia (ITP). Finally, more than a decade after initial presentation, gene panel testing revealed a novel mutation in the MAGT1 gene. Collectively, the genetic findings and clinical presentations confirm the diagnosis of X-linked immunodeficiency with magnesium defect and Epstein\u2013Barr virus infection and neoplasia (XMEN). MAGT1 is an evolutionarily conserved, magnesium-specific transporter expressed in all mammalian cells that plays an essential role in magnesium homeostasis. MAGT1 also acts as an accessory protein for STT3B, as catalytic subunits of the oligosaccharyltransferase protein complex, which carries out glycan chain transfer to proteins in the endoplasmic reticulum during N-glycosylation. Glycans play an essential role in the stability, maturation, and localization in glycoproteins that are important in our immune cells\u2019 function. Mutation of the gene resulted in a rare X-linked recessive condition XMEN. The disease has complete penetrance but variable expressivity. It is mainly associated with immunodeficiency, immunodysregulation, and predisposition to EBV-associated lymphoproliferation. Extraimmune manifestations have also been reported in some patient cohorts, including hepatic and neurological abnormalities. Overall, the presentation varies among patients and overlaps with other clinical entities, in which diagnosis is challenging. Before the era of NGS, traditional workup hinges heavily on phenotype studies, followed by single-gene sequencing. The diagnostic yield is low, and a significant delay in diagnosis is common. This case illustrated the importance of early consideration of molecular studies in complex immunological cases without obvious secondary causes as an integral part of patient management.<\/jats:p>","DOI":"10.1155\/2022\/2390167","type":"journal-article","created":{"date-parts":[[2022,2,15]],"date-time":"2022-02-15T01:25:13Z","timestamp":1644888313000},"page":"1-3","source":"Crossref","is-referenced-by-count":3,"title":["Novel MAGT1 Mutation Found in the First Chinese XMEN in Hong Kong"],"prefix":"10.1155","volume":"2022","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2724-6425","authenticated-orcid":true,"given":"Elaine Yuen Ling","family":"Au","sequence":"first","affiliation":[{"name":"Department of Pathology, Queen Mary Hospital, Pok Fu Lam, Hong Kong"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Edmund Kwok Kwan","family":"Tung","sequence":"additional","affiliation":[{"name":"Department of Pathology, Queen Mary Hospital, Pok Fu Lam, Hong Kong"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ricky Wai Ki","family":"Ip","sequence":"additional","affiliation":[{"name":"Department of Pathology, Queen Mary Hospital, Pok Fu Lam, Hong Kong"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Philip Hei","family":"Li","sequence":"additional","affiliation":[{"name":"Department of Medicine, Queen Mary Hospital, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pok Fu Lam, Hong Kong"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","reference":[{"key":"1","doi-asserted-by":"publisher","DOI":"10.1182\/blood-2013-11-538686"},{"key":"2","doi-asserted-by":"publisher","DOI":"10.1007\/s10875-020-00790-x"},{"key":"3","doi-asserted-by":"publisher","DOI":"10.3389\/fonc.2021.653266"},{"key":"4","doi-asserted-by":"publisher","DOI":"10.1172\/JCI131116"},{"key":"5","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1817815116"},{"key":"6","doi-asserted-by":"publisher","DOI":"10.4049\/jimmunol.1701467"},{"key":"7","doi-asserted-by":"publisher","DOI":"10.1038\/nature10246"},{"key":"8","doi-asserted-by":"publisher","DOI":"10.1007\/s10875-018-0573-0"},{"key":"9","doi-asserted-by":"publisher","DOI":"10.1007\/s10875-019-00732-2"}],"container-title":["Case Reports in Immunology"],"original-title":[],"language":"en","link":[{"URL":"http:\/\/downloads.hindawi.com\/journals\/crii\/2022\/2390167.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"http:\/\/downloads.hindawi.com\/journals\/crii\/2022\/2390167.xml","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"http:\/\/downloads.hindawi.com\/journals\/crii\/2022\/2390167.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,2,15]],"date-time":"2022-02-15T01:25:15Z","timestamp":1644888315000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.hindawi.com\/journals\/crii\/2022\/2390167\/"}},"subtitle":[],"editor":[{"given":"Claudio","family":"Pignata","sequence":"additional","affiliation":[],"role":[{"role":"editor","vocabulary":"crossref"}]}],"short-title":[],"issued":{"date-parts":[[2022,2,14]]},"references-count":9,"alternative-id":["2390167","2390167"],"URL":"https:\/\/doi.org\/10.1155\/2022\/2390167","relation":{},"ISSN":["2090-6617","2090-6609"],"issn-type":[{"type":"electronic","value":"2090-6617"},{"type":"print","value":"2090-6609"}],"subject":[],"published":{"date-parts":[[2022,2,14]]}}}