Clinical and genetic studies of 3 large, consanguineous, Algerian familieswith Mal de Melda

Background: Mal de Meleda (MIM 248300), also referred to as keratosis palmo plantaris transgrediens of Siemens, is a rare autosomal recessive skin diso rder with a prevalence in the general population of 1 in 100 000. The main clinical characteristics are transgressive palmoplantar keratoderma, hyperh idrosis, and perioral erythema, but there are also associated features such as brachydactyly, nail abnormalities, and lichenoid plaques. Observations: We studied the clinical and genetic characteristics of 3 larg e, consanguineous, Algerian families, including 14 affected individuals. Ho mozygosity mapping of the third family confirmed localization of the respon sible gene to 8qter in all 3 families. Conclusions: Although some differences in phenotypic expression among subje cts were noted, genetic analysis of the 3 families who shared a common ethn ic background indicated that a single gene is responsible for mal de Meleda in this population.