Novel KRT83 and KRT86 mutations associated with monilethrix.

Monilethrix is an autosomal dominant hair disorder caused by mutations in the hard keratins KRT81, KRT83 and KRT86. The affected hairs are fragile and break easily, leading to scarring alopecia. Follicular hyperkeratosis in the neck and on extensor sides of extremities is a frequently associated finding. The disorder is rare, but probably underreported because its manifestations may be mild. Mutations in KRT81 and KRT86 are the most common. Here, we report new cases from Venezuela, the Netherlands, Belgium and France. The Venezuelan kindred is special for having patients with digenic novel nucleotide changes, a KRT86 mutation associated with monilethrix and a KRT81 variant of unknown clinical significance. In the French and Dutch patients, we found novel KRT86 and KRT83 mutations. Our findings expand the mutational spectrum associated with monilethrix.