A diagnosis of tylosis with oesophageal cancer is made on the basis of a positive family history, characteristic clinical features, including cutaneous and oesophageal lesions, and genetic analysis for mutations in RHBDF2.
Dominant iRHOM2 mutations are the cause of the inherited cutaneous and oesophageal cancer-susceptibility syndrome tylosis with oesophageal cancer (TOC), suggesting a role for this protein in epithelial cells.
The tylosis oesophageal cancer (TOC) gene, localised to a small region on chromosome 17q25, has been shown to be associated with oesophageal squamous cell carcinoma.
Moreover, a locus responsible for hereditary focal non-epidermolytic palmoplantar keratoderma (tylosis oesophageal cancer; TOC), a condition associated with esophageal cancer, has been mapped to the same band.
Moreover, a genetic locus for hereditary focal non-epidermolytic palmoplantar keratoderma, a condition associated with cancer of the esophagus (TOC; Tylosis with Oesophageal Cancer), lies in the same region.
Recently, the tylosis oesophageal cancer (TOC) gene locus has been mapped to 17q25 by linkage analyses of pedigrees with focal nonepidermolytic palmoplantar keratoderma associated with a high risk of esophageal cancer development.