PRF1 and autoimmune lymphoproliferative syndrome: NGS using DNA extracted from whole blood of P1 (Figure 1) revealed two germline heterozygous mutations in PRF1 (c.1179C>A; p.Cys393Ter) and UNC13D (c.2411A>G; p.Tyr804Cys) genes (Figures 1A, B), both considered as ALPS-phenotype-modifiers but not ALPS-causing genes (11, 12, 15).