Genetic analyses failed to detect an ALPS-related gene mutation; however, whole exome sequencing and other genetic analyses revealed somatic mosaicism for the G13D NRAS mutation.
We show here that the salient features of ALPS as well as a predisposition to hematological malignancies can be caused by a heterozygous germline Gly13Asp activating mutation of the NRAS oncogene that does not impair CD95-mediated apoptosis.