Age at onset of ALPS as a function of genotype. (A) Patients with germline TNFRSF6 mutation and a somatic event impairing the second TNFRSF6 allele (“biallelic” patients) had a later onset than germline-only ALPS-FAS or ALPS-sFAS patients. (B) ALPS-FAS patients with germline ECD mutations (including patients with TNFRSF6 biallelism) tended to be older at ALPS onset than patients with ICD mutation, although this difference was not statistically significant. ALPS-sFAS patients had the lowest age at ALPS onset. *P < .05; ns indicates nonsignificant.