X-linked lymphoproliferative syndrome

X-linked lymphoproliferative syndrome (Purtil's syndrome, Duncan's disease, OMIM: 308240) is an X-linked inherited disease caused by a mutation in the SH2D1A gene (also called SAP, localization Xq25). This mutation leads to uncontrolled cytotoxic T-cell responses to Ebstein-Barr virus (EBV). The function of the SLAM molecule (Signaling lymphocyte activation molecule), which affects the cooperation of T- and B-lymphocytes, is impaired.

Affected individuals are healthy until the first contact with EBV, which can result in three different reactions:


 * 1) Infectious mononucleosis – with severe, often fatal consequences, 50% of cases.
 * 2) Lymphoproliferative syndrome – mainly affecting the B-line, 25% of cases.
 * 3) Hypogammaglobulinemia –25% of cases.

All three conditions can occur in one patient over time. The overall prognosis is not favorable, 70% of boys die within 10 years of age.

Related

 * Primary immunodeficiency