Mosaic schwannomatosis

Definition

A rare mosaic form of schwannomatosis characterized by findings typical of schwannomatosis, namely multiple benign nerve sheath tumors called schwannomas. Mosaic form is caused by postzygotic pathogenic variants in SMARCB1 or LZTR1. In mosaic schwannomatosis the allelic/tissue distribution of the pathogenic variant clearly suggests mosaicism. The phenotype can be milder than in schwannomatosis.