KRT86 Gene: Keratin 86 – Function, Mutations, and Monilethrix | NCBI, UniProt, OMIM

KRT86 (keratin 86) is a protein-coding gene located on chromosome 12q13.13. It encodes a type II (basic) hair keratin, which heterodimerizes with type I keratins to form intermediate filaments essential for the structural integrity of hair shafts. Mutations in KRT86 are a known cause of autosomal dominant monilethrix, a hair disorder characterized by beaded, fragile hair and often associated with follicular hyperkeratosis. The gene is expressed predominantly in the hair follicle cortex and is also detected in certain epithelial tissues.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• Intermediate filament organization (Reactome: R-HSA-6809371)

• Keratinization (Reactome: R-HSA-6805567)

• Formation of the cornified envelope (Reactome: R-HSA-6809374)

Keratin 86 (KRT86) is a 493-amino-acid type II hair keratin with a molecular weight of approximately 55 kDa. It contains a central alpha-helical rod domain flanked by non-helical head and tail regions. The rod domain features heptad repeats that facilitate coiled-coil dimerization with type I hair keratins (e.g., KRT31, KRT35). These dimers assemble into intermediate filaments, providing mechanical resilience to hair shafts. Mutations in the helix initiation motif of the rod domain are a well-established cause of monilethrix. The protein is highly expressed in the hair follicle cortex and is also detected at low levels in other stratified epithelia.