Progressive retinal atrophy (dominant form of PRA)
Progressive retinal atrophy (PRA) is a leading hereditary cause of blindness in pedigree dogs as is its counterpart retinitis pigmentosa (RP) in humans. PRA shows genetic heterogeneity, as does RP, with several distinct forms already recognized and several more remaining to be investigated. The retina is a thin layer of neural cells that lines the back of the eyeball. The vertebrate retina contains photoreceptor cells (rods and cones) that respond to light. The cones mediate high-resolution vision and colour vision. The rods mediate lower-resolution, black-and-white, night vision. The degeneration of the retina results in loss of vision, often leading to blindness. One can distinguish between late onset forms of PRA and early onset (whelp-age) dysplastic changes. The clinical and ophthalmologic signs of both forms are similar. Affected dogs suffer from bilateral Mydriasis, the reflection of the Tapetum lucidum is increased and the retinal vascular network appears atrophic. Currently, there is no treatment for the disease.
Bull Mastiff and English Mastiff These both dog breeds suffer from a form of PRA which is inherited as autosomal-dominant trait in contrast to the autosomal-recessive inheritance of other PRA forms. The PRA of the Bull Mastiff and English Mastiff occur during adulthood (late onset form). This means that rod vision can be normal early in life and degeneration slowly spreads from a disease focus in one retinal region. Loss of vision occurs at relatively late age and is therefore initially often not recognised. The genetic testing allows the identification of carriers and affected dogs at early age long time before the disease develops.
The DNA test is performed out of EDTA blood or buccal swabs. Required swabs can be ordered free of charge. (Buccal swab order-form). If a swab is sent in, possibly the genetic material is not sufficient to run the test. In this case it would be best to send in an EDTA blood sample.
Please send in your sample together with the lab order genetic. Results will be transmitted optionally via post, fax or email. After completion of the test you will receive a separate invoice. Payment can be made via credit card or bank transfer. Breeding club discounts apply if a copy of the membership card is sent together with the respective samples. Due to administrative reasons the invoiced price can not be altered subsequently.