Familial colorectal cancer type X: genetic profiles and phenotypic features.

Heredity is a major cause of colorectal cancer, but although several rare high-risk syndromes have been linked to disease-predisposing mutations, the genetic mechanisms are undetermined in the majority of families suspected of hereditary cancer. We review the clinical presentation, histopathologic features, and the genetic and epigenetic profiles of the familial colorectal cancer type X (FCCTX) syndrome with the aim to delineate tumor characteristics that may contribute to refined diagnostics and optimized tumor prevention.