Is autoimmune lymphoproliferative syndrome inherited ?
In most people with ALPS, including the majority of those with FAS gene mutations, this condition is inherited in an autosomal dominant pattern, which means one copy of an altered gene in each cell is sufficient to cause the disorder. In these cases, an affected person usually inherits the mutation from one affected parent. Other cases with an autosomal dominant pattern result from new (de novo) gene mutations that occur early in embryonic development in people with no history of the disorder in their family.  In a small number of cases, including some cases caused by FAS gene mutations, ALPS is inherited in an autosomal recessive pattern, which means both copies of a gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.  ALPS can also arise from a mutation in lymphocytes that is not inherited but instead occurs during an individual's lifetime. This alteration is called a somatic mutation.