Identification of Genes Involved in Inherited Ectodermal Dysplasias

The study investigated the genetic basis of ectodermal dysplasias (EDs) in five consanguineous Pakistani families. Three families (A, B, and C) had autosomal recessive ED affecting hair and nails, while two families (D and E) had autosomal recessive hypohidrotic ED. In family A, a mutation in the KRTHB5 gene on chromosome 12 was identified, marking the first direct evidence of molecular pathogenesis in pure hair-nail EDs. Family B showed linkage to chromosome 12, but no specific mutation was found, suggesting a regulatory region mutation. Family C's ED gene was linked to chromosome 17, but no mutations were identified in the examined genes. For families D and E, novel mutations in the EDAR gene were discovered, contributing to the understanding of autosomal recessive hypohidrotic ED.