COCKAYNES-SYNDROME - CORRELATION OF CLINICAL-FEATURES WITH CELLULAR-SENSITIVITY OF RNA-SYNTHESIS TO UV IRRADIATION

Cockayne's syndrome (CS) is a rare autosomal recessive disorder with d warfism, mental retardation, and otherwise clinically heterogeneous fe atures. In cultured CS fibroblasts, the failure of RNA synthesis to re cover to normal rates after UV-C irradiation provides a useful and rel atively simple diagnostic test. We have measured post-UV-C RNA synthes is in 52 patients for whom a clinical diagnosis of CS was considered a possibility. Twenty-nine patients showed the defect characteristic of CS cells, and 23 had a normal response. We have attempted to correlat e the cellular diagnosis with the different clinical features of the d isorder. Clinical details of the patients were obtained from referring clinicians in the form of a questionnaire. Our results show that, apa rt from the cardinal features of dwarfism and mental retardation, sun sensitivity correlated best with a positive cellular diagnosis. Pigmen tary retinopathy, gait defects, and dental caries were also good posit ive indicators, although several patients with a positive cellular dia gnosis did not have these features.