Albipunctatus retinopathy in inherited interstitial nephritis

We describe here a patient with familial interstitial nephritis and albipunctatus retinopathy. Albipunctatus is often seen in patients with Alport syndrome, which is an X-linked disorder characterised in affected males by renal failure by the age of 25, high-tone sensorineural deafness, anterior lenti-conus and albipunctatus. The diagnosis of Alport syndrome depends on the electron microscopic appearance of a trabeculated glomerular basement membrane (GBM); and mutations have been demonstrated in the gene for the alpha 5 chain of type IV collagen. In the familial interstitial nephritis described here, the inheritance was autosomal dominant, renal failure developed in middle age, and there was no associated hearing loss or anterior lenticonus.
The finding of albipunctatus retinopathy in this patient suggests that the genetic mutation responsible involves a protein common to both retinal and interstitial basement membranes. In addition, we conclude that the demonstration of albipunctatus in an individual with familial nephritis does not necessarily indicate that the underlying disease is Alport syndrome.