SMARCB1 and schwannomatosis: In addition, a recent deep massive parallel sequencing study of 35 schwannomatosis cases (Piotrowski et al., 2021) reported two novel deep intronic variants in intron 4 of SMARCB1 (NM_003073.5:c.500+883T>G and NM_003073.5:c.500+887G>A).