GNAS gene mutation may be present only transiently during colorectal tumorigenesis.

Mutations of the gene GNAS have been shown to activate the adenylate cyclase gene and lead to constitutive cAMP signaling. Several preliminary reports have suggested a role for GNAS gene mutations during colorectal carcinogenesis, particularly mucinous carcinomas. The aim of this study was to clarify the incidence of GNAS mutations in adenomas (tubular, tubulovillous, and villous), carcinomas with residual adenoma, and carcinomas, and to relate these findings to mutations of the KRAS gene and to the mucinous status of the tumors.