KRT85 and ectodermal dysplasia syndrome: Of the K85 mutations related to ectodermal dysplasia of hair and nail type, a two‐nucleotide (C1448T1449) deletion (delCT) in the protein tail domain of K85 interfered with the K85–K35 filament formation and gave only aggregates, whereas a missense mutation (233A>G) that replaces Arg78 with His (R78H) in the head domain of K85 did not interfere with the filament formation.