The results revealed a substantially lower age of polyposis diagnosis for patients belonging to the severe FAP group (harbouring adenomatous polyposis coli (APC) variants in the mutation cluster region (MCR)) and high age for patients in the attenuated familial adenomatous polyposis (AFAP) group for SNPs rs1761667 and rs1984112. The gene discussed is APC; the disease is attenuated familial adenomatous polyposis.