In a recent study, we demonstrated that JRTs with GI polyps harbor an identical germline variant in the adenomatous polyposis coli (APC) gene, c.[462_463delinsTT] (GenBank ID: LC598892.1) in a heterozygous state; thus, this is an autosomal dominant hereditary disorder (OMIA ID 001916–9615) [6]. Here, APC is linked to autosomal dominant disease.