[Clinical examination of renal function in Cockayne syndrome].

Cockayne syndrome (CS) is a rare hereditary disease, characterized by profound postnatal brain and somatic growth failure and by the degeneration of multiple tissues resulting in cachexia, dementia, and premature aging. This syndrome is often associated with renal dysfunction, which usually correlates with the patient's prognosis. In the present study, we evaluated the longitudinal changes in serum creatinine and serum cystatin C levels in three patients with CS to examine whether these markers can help detect renal disorders at the earlier stages. The serum creatinine level in these CS patients gradually exceeded the reference level from 5 to 7 years of age, after correcting for body length. The cystatin C level of the CS patients increased to above the reference level while their estimated glomerular filtration rate remained within stage 2 or 3. Thus, we conclude that the serum creatinine level, following correction by body length, is very useful for the evaluation of renal function in CS. Moreover, the appropriate estimation of renal function facilities the administration of suitable medication, thus avoiding some harmful effects on the kidney.