A Missense Mutation in the Type II Hair Keratin hHb3 Is Associated with Monilethrix

The study identified a missense mutation in the type II hair keratin hHb3 associated with monilethrix, an autosomal dominant hair disorder that can lead to scarring alopecia. The research involved three patients with monilethrix, and in one patient, a heterozygous missense mutation was found in hHb3, resulting in the substitution of glutamic acid with lysine at position 407 (E407K) in the helix termination motif. This mutation is similar to known mutations in hHb1 and hHb6, suggesting that hHb3 mutations can also cause monilethrix. The findings highlighted the role of specific residues in trichocyte keratin genes in the development of this hair disorder.