A clinical study of a family with Cockayne's syndrome.

SUMMARY Two sibs with Cockayne's syndrome are described. The recognised cellular sensitivity to ultraviolet light is confirmed. The clinical features in the two children are described and comparisons are made with some forms of xeroderma pigmentosum, a condition in which there is progressive neurological degeneration and cellular sensitivity to ultraviolet irradiation. In 1936 Cockaynel described two sibs with dwarfism, progressive mental retardation, and erythematous dermatitis, who went on to develop odd facial appearance and visual failure associated with unusual retinal pigment.2 Later reports have confirmed that this is a distinct syndrome inherited in an autosomal recessive manner, although there are fewer than 40 cases reported. Recent interest in Cockayne's syndrome has been renewed since cultured skin fibroblasts from these patients were shown to be unusually sensitive to killing by ultraviolet light.3 At least three syndromes are known to demonstrate an unusual clinical sensitivity to one of a number of environmental agents. These are xeroderma pigmentosum (UV), Cock-ayne's syndrome (UV), and ataxia telangiectasia (ionising radiation). Cultured cells from patients with xeroderma pigmentosum and Cockayne's syndrome are sensitive to UV light and to specific chemicals, producing similar nuclear abnormalities .5-7 Cells from patients with ataxia telangiectasia are unusually sensitive to ionising radiation and the radiomimetic chemical bleomycin.8 9 In addition, cells cultured from patients with Fanconi's anaemia are sensitive to DNA-DNA cross-linking agents,10 and Gianelli et all' have reported that cultured cells from patients with Bloom's syndrome are UV sensitive, but this is not a consistent finding.12 Particular enzyme defects in DNA repair have been reported for both xeroderma pigmentosum'3 and ataxia telangiectasia14 15 which would account for the in vitro sensitivity and the clinical manifestations , but these studies are not complete. This paper describes a family where two of the three children have Cockayne's syndrome. The association between this progressive neurological disease and sensitivity to UV light is presented and discussed. Case reports The first and third children in this sibship who have Cockayne's syndrome are described below. The second child is normal and healthy as are both parents. There is no evidence of consanguinity. CASE 1 The girl was born after an uneventful pregnancy at term weighing 2-4 kg (<1Oth centile). The neonatal period was complicated by slow weight gain and a recurrent erythematous desquamating rash on her face and hands which was particularly obvious after exposure to sunlight. Her growth and development continued normally until the age of …