A NOVEL DINUCLEOTIDE MUTATION IN KERATIN-10 IN THE ANNULAR EPIDERMOLYTIC ICHTHYOSIS VARIANT OF BULLOUS CONGENITAL ICHTHYOSIFORM ERYTHRODERMA

Annular epidermolytic ichthyosis has recently been delineated as a dis tinct clinical phenotype within the spectrum of epidermolytic keratini zation disorders. The pattern of inheritance of the disorder is consis tent with an autosomal dominant mode of transmission. Here we report a second incidence of this disorder in a family with two affected gener ations. The proband suffered from bullous ichthyosis and had bouts of disease activity associated with the development of numerous annular a nd polycyclic erythematous, hyperkeratotic plaques on the trunk and th e proximal extremities. Histologic examination showed the typical path ology of epidermolytic hyperkeratosis, and ultrastructural analysis re vealed abnormal keratin filament networks and tonofilament clumping wi th a perinuclear distribution. Molecular analysis revealed a novel tan dem CG to GA 2-bp mutation in the same allele of keratin 10 in affecte d individuals, resulting in an arginine to glutamate substitution at r esidue 83 (R83E) of the 2B helical segment. We conclude that annular e pidermolytic ichthyosis should be considered a variant of bullous cong enital ichthyosiform erythroderma.