X-linked lymphoproliferative disease type 1 (XLP1) due to a “de novo” missense SH2D1A Hemizygous Mutation Leading to Predominantly Antibody Deficiency
Listed in
This article is not in any list yet, why not save it to one of your lists.Abstract
Purpose The SAP-SLAM receptor system plays a critical role in immune regulation, with SAP deficiency leading to apoptosis resistance in T cells and disrupting immune homeostasis, as seen in XLP-1. This disorder, characterized by uncontrolled lymphoproliferation, often presents with a variable clinical spectrum. Methods We report a case of XLP-1 with dysgammaglobulinemia in a patient initially diagnosed with pediatric-onset CVID. Through quantitative and functional analysis of the SH2D1A c.164G > A (p.Arg55Gln) variant, we confirmed its pathogenicity. Results Our findings demonstrate that this variant significantly impairs B cell differentiation and proliferation independently of T cell interactions Conclusion These results support the pathogenic nature of SH2D1A R55Q and advocate for its reclassification as a pathogenic mutation.