Identical Phenotype in Patients with Somatic and Germline CD95 Mutations Requires a New Diagnostic Approach to Autoimmune Lymphoproliferative Syndrome

In a patient with a somatic mutation in the CD95 gene, the long-term evolution of the clinical phenotype was indistinguishable from that of patients with autoimmune lymphoproliferative syndrome caused by germline CD95 mutations. A new diagnostic algorithm for autoimmune lymphoproliferative syndrome is suggested incorporating studies on sorted TCRα/β+CD3+CD8−CD4− T cells.