Rare congenital lymphoid disorder due to mutations in certain fas-fas ligand pathway genes. known causes include mutations in fas, tnfsf6, nras, casp8, and casp10 proteins. clinical features include lymphadenopathy; splenomegaly; and autoimmunity.

Autoimmune lymphoproliferative syndrome (ALPS) is a form of lymphoproliferative disorder (LPDs). It affects lymphocyte apoptosis. It is a rare genetic disorder of abnormal lymphocyte survival caused by defective Fas mediated apoptosis...