A NOVEL H1 MUTATION IN THE KERATIN-1 CHAIN IN EPIDERMOLYTIC HYPERKERATOSIS

We report a novel mutation in a case of epidermolytic hyperkeratosis t hat results in a proline for arginine substitution in the penultimate residue position of the H1 subdomain of the keratin 1 chain, which is near the beginning of the rod domain. This causes a severe clinical di sease classified as PS-2. Therefore, the H1 subdomain is probably equa lly important for the maintenance of keratin intermediate filament int egrity as the rod domain. Since earlier concepts had implied that muta tions in the H1 subdomain produce milder disease, this case suggest th at attempts to correlate mutations with disease presentation remain pr oblematic.