An Autosomal Recessive Form of Monilethrix Is Caused by Mutations in DSG4: Clinical Overlap with Localized Autosomal Recessive Hypotrichosis

The study identified mutations in the DSG4 gene as the cause of an autosomal recessive form of monilethrix in 12 Jewish families from Iraq, Iran, and Morocco, involving 24 family members, including 15 patients. This form was characterized by fragile, brittle hair and follicular hyperkeratosis, differing from the autosomal dominant form linked to keratin gene mutations. Four different DSG4 mutations were found, with a common haplotype on chromosome 18q among Iraqi patients, suggesting a genetic overlap with localized autosomal recessive hypotrichosis. The study emphasized the role of DSG4 in hair disorders and its implications for genetic counseling, noting the severity of the recessive form with more extensive alopecia and skin manifestations.