the clinical and phenotypic features of two siblings (a 12 years old girl and her 7 year old brother) with cockayne syndrome are described. the main problems were mild to moderate mental retardation, dwarfism, clumsy gait, photosensitive skin lesions and progeroid (senile like) appearance. brain ct - scans revealed symmetrical, well defined areas of calcification mainly located at lenticular nu...