Approximately one-third of pediatric malignant rhabdoid tumors are linked to germline SWI/SNF alterations (SMARCB1/INI1, rarely SMARCA4) resulting in occasional familial clustering of these highly aggressive malignancies (so-called rhabdoid tumor predisposition syndrome, RTPS, types 1 and 2, respectively).
In the last decade, sporadic publications have shown that a different SWI/SNF protein, brahma-related gene 1 (BRG1), encoded by the <i>SMARCA4</i> gene, is associated with a similar rhabdoid phenotype and possible germline mutation termed rhabdoid tumor predisposition syndrome type 2.