A rare autosomal dominant disorder.
A chronic, nonmalignant process with noninfectious lymphadenopathy or splenomegaly or both.
Associated with a defective lymphocyte apoptosis and somatic or germline pathogenic mutation in FAS, FAS ligand or CASP10.
Approximately 400 patients worldwide.
Associated with defective T-cell lymphocyte apoptosis and the accumulation of double negative T cells, which expressed CD3 and T cell receptor alpha Beta but lack both CD4 and CD8.
The accumulation of double negative T-cells result in lymph node enlargement and splenomegaly in the early years.
Associated with elevated plasma soluble FAS ligand levels.
Associated with elevated plasma interleukin-10 levels.
Associated with elevated serum vitamin B12 levels and elevated plasma interleukin-18 levels.
Associated with autoimmune cytopenias-hemolytic anemia, thrombocytopenia, or neutropenia, and elevated IgG levels with a polyclonal gammopathy.
Family history of a nonmalignant or noninfectious lymphoproliferative disease with or without autoimmunity is frequently present.
Pancytopenia does not appear at the time of diagnosis, but develops months to years later.
Most common mutations occur in the gene for the FAS receptor on activating T cells.
The FAS ligand is expressed on activated T cells and B cells and is associated with FAS-associated death domain (FADD) triggering the caspase cascade of the extrinsic pathway.