{"entity":{"id":"x-linked-lymphoproliferative-disease","kind":"term","name":"X-linked lymphoproliferative disease type 1 (SAP deficiency)","aka":["XLP","XLP1","XLP-1","Duncan disease","Purtilo syndrome","SAP deficiency","SH2D1A deficiency"],"tldr":"X-linked lymphoproliferative disease is a rare inherited immune deficiency, mainly in boys, caused by a fault in the SH2D1A gene, in which the glandular fever virus can trigger a life-threatening overreaction of the immune system or lymphoma. A stem cell transplant is the treatment that changes its course.","summary":"X-linked; SH2D1A encodes SAP, the SLAM-associated protein, identified in 1998. Epstein-Barr virus infection drives haemophagocytic lymphohistiocytosis, hypogammaglobulinaemia and lymphomas; most present before age 10, though adult onset and affected females are reported (Frontiers in Immunology 2025 review).\n\nB-cell lymphomas are treated with standard chemotherapy followed by expedited haematopoietic stem cell transplantation; haemophagocytic lymphohistiocytosis with the HLH-1994 regimen, with ruxolitinib reported as salvage or bridge; immunoglobulin replacement for hypogammaglobulinaemia. In a Japanese cohort of 33 patients, 21 of those not transplanted died of the disease and its complications, while 11 of 12 transplanted survived; early transplantation for asymptomatic patients is suggested and gene therapies are in development.","asOf":"2026-11-04","wikipedia":"https://en.wikipedia.org/wiki/X-linked_lymphoproliferative_disease","links":[{"label":"Li, Front Immunol 2025: X-linked lymphoproliferative disease type 1, a clinical and genetic update","url":"https://doi.org/10.3389/fimmu.2025.1620327"},{"label":"Orphanet ORPHA:538931","url":"https://www.orpha.net/en/disease/detail/538931"}],"tags":["gap-fill","hereditary"],"related":[],"cancers":[],"sections":[],"technologies":["allogeneic-hsct","germline-testing"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":["hereditary-cancer-syndromes"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":["Orphanet ORPHA:538931. SH2D1A has no target record in OnCo."],"category":"Genomics & genetics"},"route":"/terms/x-linked-lymphoproliferative-disease/","neighbours":{"technology":[{"id":"allogeneic-hsct","kind":"technology","name":"Allogeneic stem cell transplantation","route":"/technologies/allogeneic-hsct/"},{"id":"germline-testing","kind":"technology","name":"Germline (hereditary) testing","route":"/technologies/germline-testing/"}],"term":[{"id":"hereditary-cancer-syndromes","kind":"term","name":"Hereditary cancer syndromes","route":"/terms/hereditary-cancer-syndromes/"}]}}