Test Detail
rcd3-PRA (Cardigan Welsh Corgi; also described in Chinese Crested Dog and Pomeranian)
Ocular · Dog
Progressive retinal atrophy due to rod-cone dysplasia type 3 (rcd3), caused by a mutation in the PDE6A gene (alpha subunit of rod cGMP phosphodiesterase). Progressive degeneration of photoreceptors leading to blindness. The variant was first described in the Cardigan Welsh Corgi and the same variant has since been detected in the Chinese Crested Dog and the Pomeranian; it is not validated in the Pembroke Welsh Corgi.
Incidence
The variant is documented in the Cardigan Welsh Corgi (the breed in which it was described), the Chinese Crested Dog and the Pomeranian (OMIA:001314-9615). Donner et al. (2016) also document it in the Pembroke, in addition to the Cardigan, Chinese Crested and Pomeranian (OMIA:001314).
Breeder management
- Genotype breeding animals before mating\n- Do not cross carrierĂ—carrier (25% risk of affected homozygotes); carrierĂ—clear produces 0% affected and 50% carriers\n- An affected animal must not be bred; a carrier can be mated to a clear animal without producing affected offspring\n- Complementary annual ophthalmological examination (ECVO)
Specialist notes
rcd3 (PDE6A) and rcd1/rcd1a (PDE6B) affect different subunits of the same enzyme, with similar clinical pictures. Confirmation requires a PDE6A-specific genetic test. ATTENTION: the rcd3 variant was described in the CARDIGAN Welsh Corgi, not the Pembroke; verify the target breed of the laboratory's panel.
References
1. Petersen-Jones SM et al. (1999) cGMP phosphodiesterase-alpha mutation causes progressive retinal atrophy in the Cardigan Welsh corgi dog. Invest Ophthalmol Vis Sci 40(8):1637-1644. PMID: 10393029
2. Petersen-Jones SM, Zhu FX (2000) Development and use of a polymerase chain reaction-based diagnostic test for the causal mutation of progressive retinal atrophy in Cardigan Welsh Corgis. Am J Vet Res 61(7):844-846. PMID: 10895911
3. Donner J et al. (2016) Genetic panel screening of nearly 100 mutations reveals new insights into the breed distribution of risk variants for canine hereditary disorders. PLoS One 11(8):e0161005. PMID: 27525650
4. OMIA:001314-9615 (Retinal atrophy - Rod-cone dysplasia 3, PDE6A-related).
2. Petersen-Jones SM, Zhu FX (2000) Development and use of a polymerase chain reaction-based diagnostic test for the causal mutation of progressive retinal atrophy in Cardigan Welsh Corgis. Am J Vet Res 61(7):844-846. PMID: 10895911
3. Donner J et al. (2016) Genetic panel screening of nearly 100 mutations reveals new insights into the breed distribution of risk variants for canine hereditary disorders. PLoS One 11(8):e0161005. PMID: 27525650
4. OMIA:001314-9615 (Retinal atrophy - Rod-cone dysplasia 3, PDE6A-related).