[Genetics of kidney diseases and renal fibrosis]

Renal fibrosis is found in genetic kidney diseases. In some of them, fibrosis may be due to mechanisms not dependent on the gene defect. In other cases, fibrosis depends more specifically on the gene defect: e.g. in juvenile nephronophthisis where interstitial fibrosis predominates, or in Alport's syndrome where glomerulosclerosis is triggered probably by unbalanced distribution of alpha chains of type IV collagen in glomerular basement membrane. Study of genes predisposing to renal fibrosis and progression is more complex. Genes regulating the renin-angiotensin system have been considered. The DD polymorphism of the converting enzyme gene may be associated with a more rapid progression rate of renal failure in glomerular and non-glomerular diseases. This remains, however, to be confirmed in more appropriate studies.