A case of spontaneous mutation in the keratin 9 gene associated with epidermolytic palmoplantar keratoderma

Epidermolytic palmoplantar keratoderma appears to be due to defects in keratin 9, the palmoplantar specific type 1 keratin. We report a case of spontaneous mutation, a C to T transition at codon 162, resulting in an arginine to tryptophan substitution in the 1 A region of the alpha helical rod domain of keratin 9. This provides further evidence that this codon is an important spot for mutation in keratin 9.