19p13.2

BAF190,BAF190A,BRG1,CSS4,MRD16,RTPS2,SNF2,SNF2-beta,SNF2L4,SNF2LB,SWI2,hSNF2b

Various cancers

SMARCA4 somatic mutations have been identified in some cancer cell lines including those from the lung, prostate, breast, pancreas and colon. While somatic mutations have been detected in a small subset of lung primary tumors, about one third of the lung cancer cell lines of the non-small cell lung cancer type harbour inactivating SMARCA4 somatic mutations. All mutations are homozygous and most of them predict truncated proteins. The type of mutations commonly observed include nonsense, indels and large deletions. Although less frequently, missense mutations have also been reported. Four of the aminoacid substitutions found in human lung and colorectal cancer, the p.W764R, p.G1160R, p.L1163P and p.S1176C represent changes in highly conserved residues within the ATPase/helicase domain. In vitro generated mutations of some highly conserved aminoacid within this motif lead to a seriously diminished catalytic activity of SMARCA4.
SMARCA4 germ-line mutations have not been reported so far.

The lost of either SMARCA4 or SMARCA2, detected by immunostaining, predicts decreased survival in some cancer patients.