Cockayne syndrome in 2 siblings.

ABSTRACT Cockayne syndrome is a rare autosomal recessive condition characterized by growth failure and multisystem progressive degeneration. We report and describe this syndrome in a Jordanian brother and sister with Cockayne syndrome with first cousin parents. Clinical features included short stature, cachectic senile look, neurological deterioration, photosensitivity, mental retardation, hearing impairment and carious teeth. The phenotype is compatible with a mild variant of type I Cockayne syndrome. They showed an exaggerated response to growth hormone provocation test, with slightly elevated basal insulin-like growth factor 1 levels. The radiological findings of thinning of ribs and slender femora with narrow medullary canals have not previously been reported in this syndrome. We discuss the implications of these findings.