A rare autosomal dominant inherited hair shaft disorder caused by mutations in certain cuticular type II keratin genes. It is characterized by the presence of thin, fragile hairs that appear beaded.

Rare autosomal dominant disorder of the hair shaft. The clinical features of the disease include HYPOTRICHOSIS, dry, and/or brittle hair, with varying degrees of ALOPECIA. Mutations in the hair-specific keratin genes KRTHB1, KRTHB3, or KRTHB6 are associated with monilethrix. Autosomal recessive monilethrix with limited HYPOTRICHOSIS are also known. Mutations in Dsg4, Liph, and P2ry5 protein genes are associated with the recessive form of monilethrix.

The hair shaft has a beaded appearance due to the presence of elliptical nodes that have the diameter of normal hair and are medullated, regularly separated by internodes that are narrow, devoid of medulla and are the site of fracture.

Monilethrix is an autosomal dominant disorder characterized by a beaded appearance of the hair due to periodic thinning of the shaft. The phenotype results in hair fragility and patchy dystrophic alopecia.

Monilethrix is a rare condition caused by a defect in the hair shaft resulting in hair which appears dry, dull, and brittle, and which breaks spontaneously or with mild trauma. The age of onset, severity, and course may vary from person to person.