has material basis in germline mutation in SH2D1A X-linked lymphoproliferative syndrome X-linked recessive disease X-linked lymphoproliferative disease due to SH2D1A deficiency https://github.com/monarch-initiative/mondo/issues/4521 MONDO:0024551 A rare, genetic, primary immunodeficiency disorder characterized by an abnormal immune response to Epstein-Barr virus (EBV) infection, caused by hemizygous mutations in the X-linked SH2D1A gene, resulting in B cell lymphoproliferation and manifesting with various phenotypes which include EBV-driven severe or fulminant mononucleosis, hemophagocytic lymphohistiocytosis (presenting with fulminant hepatitis, hepatic necrosis, bone marrow hypoplasia, and neurological involvement), hypogammaglobulinemia, and B-cell lymphoma. Additional variable manifestations include vasculitis, lymphomatoid granulomatosis, aplastic anemia, and chronic gastritis. Occasionally, T-cell lymphoma may be observed. Laboratory findings include normal or increased activated T cells and reduced memory B cells. MEDGEN:1770239 lymphoproliferative syndrome, X-linked, 1, X-linked recessive UMLS:C5399825 XLP1 OMIM:308240 GARD:0007906 Epstein-Barr Virus infection, familial fatal immunodeficiency, X-linked progressive combined variable infectious mononucleosis, Severe, susceptibility to Orphanet:538931 lymphoproliferative syndrome, X-linked, 1 immunodeficiency 5 Lyp X-linked lymphoproliferative disease due to SH2D1A deficiency EBV infection, Severe, susceptibility to Purtilo syndrome lymphoproliferative disease, X-linked Duncan disease Xlp