Contemporary diagnostic approach in Alport's syndrome.

Diagnosis of Alport's syndrome rests on clinical, pathological and genetic criteria. The clinical criteria include positive family history, persistent microhematuria and extrarenal abnormalities involving eyes and ears. Besides kidney biopsy, skin biopsy has emerged recently as an interesting diagnostic tool: the absence of staining for the alpha5 chain of type IV collagen in the epidermal basement membrane is highly specific of x-linked Alport's syndrome but its sensitivity is approximately 75%. Genetic diagnosis is based on direct identification of the mutation involved (positive in 50% of the families, after long and tedious search) or on linkage analysis. An integrated approach to diagnosis of Alport's syndrome (which encompasses various diseases characterized by different molecular defects) has been greatly facilitated in the last 10 years.