Somatic gene mutations constitute key events in the malignant transformation of human cells. Somatic mutation can either actively speed up the growth of tumour cells or relax the growth constraints normally imposed upon them, thereby conferring a selective (proliferative) advantage at the cellular level.
Neurofibromatosis type-1 (NF1) affects 1/3,000-4,000 individuals worldwide and is caused by the inactivation of the NF1 tumour suppressor gene, which encodes the
protein neurofibromin. Consistent with Knudson's two-hit hypothesis, NF1 patients harbouring a heterozygous germline NF1 mutation develop
neurofibromas upon somatic mutation of the second, wild-type, NF1 allele. While the identification of somatic mutations in NF1 patients has always been problematic on account of the extensive cellular heterogeneity manifested by
neurofibromas, the classification of NF1 somatic mutations is a prerequisite for understanding the complex molecular mechanisms underlying NF1
tumorigenesis. Here, the known somatic mutational spectrum for the NF1 gene in a range of NF1-associated
neoplasms - including peripheral nerve sheath tumours (
neurofibromas), malignant peripheral nerve sheath tumours, gastrointestinal stromal tumours, gastric
carcinoid, juvenile myelomonocytic leukaemia, glomus tumours,
astrocytomas and phaeochromocytomas - have been collated and analysed.