SINCE 1990, it has been known that mutations in keratin genes can cause various hereditary epithelial disorders. The deleterious mutations are not randomly distributed along a keratin molecule, but occur preferentially in those parts of the molecule that are essential for ordered filament formation. The main areas involved in this process are the helix initiation motif or the helix termination motif. The hereditary hair disease monilethrix can be caused by a mutation in hair keratins.
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