[Palmoplantar keratosis].
Palmoplantar keratosis is a frequent hereditary disorder of keratinization in humans that have been classified into diffuse, punctate and focal forms according to the pattern of hyperkeratosis on the pal and soles. Various clinically, histopathologically and genetically distinct phenotypes can be diagnosed. Diffuse palmoplantar keratodermas can be further subdivided by the presence of epidemlysis on histopathology into epidermolytic form and non-epidermolytic form. The late onset non-epidermolytic palmoplantar keratoderma was found associated with oesophageal cancer. The causative locus designated as TOC(Tylosis with oesophageal cancer) mapped to a small region on chromosome 17q25. Frequent allelic loss was found overlapping the region in sporadic oesophageal, ovarian and breast cancers. Positional cloning and candidate gene analysis will allow identification and characterization of the TOC gene which may also be implicated in cancer development.
Dept. of Molecular Biology, Nippon Medical School.
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D002874:Chromosome Mapping; D002886:Chromosomes, Human, Pair 17; D003598:Cytoskeletal Proteins / Q000235:genetics; D051180:Desmoplakins; D004938:Esophageal Neoplasms / Q000150:complications / Q000235:genetics; D006801:Humans; D007633:Keratins / Q000235:genetics; D007645:Keratoderma, Palmoplantar / Q000235:genetics / Q000473:pathology; D019656:Loss of Heterozygosity; D010641:Phenotype
D003598:Cytoskeletal Proteins; D051180:Desmoplakins; D007633:Keratins