Recent advances in understanding the spectrum of canine generalised progressive retinal atrophy.

Canine generalised progressive retinal atrophy (gPRA) is a large and ever-increasing collection of naturally occurring, heterogeneous, progressive disorders. Most are inherited in an autosomal recessive manner and new, breed-specific forms continue to be described. The gPRAs cause photoreceptor cell death and subsequent retinal degeneration, culminating in blindness. In humans, similar inherited retinal dystrophies are recognised as retinitis pigmentosa and macular dystrophy. Molecular biological studies have revealed disease-causing mutations in several genes in humans and also in mice with retinal dystrophies. Recently, molecular genetic techniques have identified the cause of one form of gPRA in Irish setters while important candidate genes have been investigated in other breeds. Identification of mutations responsible for different forms of gPRA allows carrier and predegenerate animals to be detected using DNA-based tests. Such genetic tests will greatly facilitate the eradication of these diseases in different breeds.