Although the genetic causes of FCCTX are still unknown, several studies identified some CRC predisposing genes including BRCA2, SEMA4A, APC, BMPR1A, NTS, CDH18, RPS20, GREM1, BCR, KIF24, GALNT12, ZNF367, HABP4, GABBR2, TP53, SMAD4, and BMP4 (11–13, 22–24). This evidence concerns the gene GABBR2 and familial colorectal cancer type X.