Increasingly, we are consulted on or asked to perform colonoscopies on patients who previously underwent multigene panel testing for oncogenes associated with colorectal cancer (CRC).

NTHL1 encodes endonuclease III-like protein 1, an enzyme involved in base-excision repair that identifies and removes oxidized pyrimidines. Biallelic loss-of-function mutations of base-excision repair genes, such