SMARCB1/INI1 maternal germ line mosaicism in schwannomatosis

Abstract

Schwannomatosis is characterized by the development of multiple schwannomas of the nervous system, but without the occurrence of vestibular schwannomas. Most cases of schwannomatosis are thought to be sporadic, representing the first case in a family due to a new mutation in the causative gene. We recently identified . SMARCB1/INI1 as a schwannomatosis-predisposing gene. Here, we analyzed this gene in a schwannomatosis family with two affected children, but with clinically unaffected parents. Both affected individuals carried a constitutional . SMARCB1 mutation, c.1118+ 1G>A, that changes the donor splice site sequence of intron 8, causing skipping of exon 8 and resulting in the in-frame del..