Clinical and genetic studies of 3 large, consanguineous, Algerian families with Mal de Meleda.

BACKGROUND Mal de Meleda (MIM 248300), also referred to as keratosis palmoplantaris transgrediens of Siemens, is a rare autosomal recessive skin disorder with a prevalence in the general population of 1 in 100,000. The main clinical characteristics are transgressive palmoplantar keratoderma, hyperhidrosis, 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 large, consanguineous, Algerian families, including 14 affected individuals. Homozygosity mapping of the third family confirmed localization of the responsible gene to 8qter in all 3 families. CONCLUSIONS Although some differences in phenotypic expression among subjects were noted, genetic analysis of the 3 families who shared a common ethnic background indicated that a single gene is responsible for mal de Meleda in this population.