Renal Involvement in 2 Siblings With Cockayne Syndrome.

Renal involvement in Cockayne syndrome is rare and its pathogenesis is yet unknown. We report herein 2 cases (siblings) with Cockayne syndrome type A confirmed by biochemical and molecular assays. The first case was a 13-year-old girl who presented with nephritic syndrome and a rapidly progressive kidney failure. Her younger sister, 7 years old, exhibited hypertension, hyperfiltration, and microalbuminuria. She had hyperreninemia and hyperaldosteronemia without kidney failure or renal arterial stenosis. Renal biopsy, performed the older sister, revealed cystic focal segmental glomerulosclerosis, arteriosclerosis, tubulointerstitial fibrosis, and tubular atrophy. The different clinical phenotypes in the two siblings support the absence of an obvious genotype-phenotype correlation in Cockayne syndrome type A patients. In the older sister, the particular focal glomerular sclerosis and senile lesions assume that kidney disease in Cockayne syndrome may be related to prematurely aging secondary to a defective nucleotide repair.