Autoimmune lymphoproliferative syndrome (ALPS)
is a disorder in which the body cannot properly regulate the number of immune system cells (lymphocytes). This results in the overproduction of lymphocytes, which build up and cause enlargement of the lymph nodes, liver and spleen. Affected individuals can have a variety of autoimmune disorders, most of which damage the blood cells; some of the autoimmune disorders associated with ALPS can also damage the kidneys, liver, eyes, nerves, or connective tissues. Other signs and symptoms may include skin rashes or panniculitis; arthritis; inflammation of blood vessels (vasculitis); mouth sores; premature ovarian failure; and the development of neurological damage. ALPS is caused by mutations in the FAS gene in about 75% of cases. It is usually inherited in an autosomal dominant manner, although some severe cases are inherited in an autosomal recessive manner. Management may include steroids or other medications, blood transfusions, and/or splenectomy depending on the severity of the disorder. ALPS is categorized into several types based mainly on the genetic cause. Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.