Costello syndrome with decreased gene expression of elastin in cultured dermal fibroblasts.

We report a case of Costello syndrome. A 2-year-old Japanese boy presented with a 'coarse' face, curly hair and loose skin of the dorsal aspect of the hands and feet with dark pigmentation. A skin biopsy of the dorsal aspect of the left hand revealed hyperkeratosis and papillomatosis of the epidermis, hyperpigmentation of the basal layer, and shortening and rupture of elastic fibers of the dermis. Electron microscopy of dermal elastic fibers showed a decreased amount of elastin with an exposed appearance of microfibrils. In Northern blot analysis of cultured dermal fibroblasts, elastin mRNA levels were reduced, suggesting a decrease in elastin production at the lesions of loose skin. Copyright 2000 S. Karger AG, Basel