The Y165C and 1103delC mutations significantly reduce MUTYH protein stability and thus repair activity, whereas the G382D mutation produces dysfunctional protein only suggesting different functional molecular mechanisms by which the MAP phenotype may contribute to the development of CRC.
Biallelic mutations for Y165C and/or G382D were not found in any of those undergoing screening colonoscopy with 0-3 polyps (n = 400), in those APC-negative patients with <20 adenomatous polyps (n = 26), or in those with CRC who were older than 50 years (n = 328).