Test Detail
Disproportionate Dwarfism (Dogo Argentino, Vizsla)
Musculoesquelético · Dog
A form of disproportionate dwarfism, hereditary and autosomal recessive, described in the Dogo Argentino and the Vizsla. In the Dogo Argentino it is caused by a splice variant in PRKG2 that affects chondrocyte differentiation, with shortening and deformity of the limbs and premature closure of the distal ulnar physis. In the Vizsla (designated SD3) it is associated with a missense variant in PCYT1A, with marked shortening and deformity of the humerus and femur. In both cases affected animals have a relatively normal-sized trunk and short, deformed limbs.
Incidence
Affected breeds: Dogo Argentino and Vizsla. Carrier frequencies are not reliably published on a large scale; cases are concentrated in consanguineous lines. In the Vizsla, cases have been described in related families and the specific genetic test is available.
Breeder management
- Test breeding animals with the breed-specific test (PRKG2 in the Dogo Argentino, PCYT1A in the Vizsla)
- Do not mate two carriers: 25% risk of affected homozygotes
- A carrier may be mated with a clear animal; test offspring intended for breeding
- Exclude affected homozygous animals from breeding
- In the Vizsla, watch for possible heterogeneity: a clear result for PCYT1A does not rule out other causes of dwarfism
- Do not mate two carriers: 25% risk of affected homozygotes
- A carrier may be mated with a clear animal; test offspring intended for breeding
- Exclude affected homozygous animals from breeding
- In the Vizsla, watch for possible heterogeneity: a clear result for PCYT1A does not rule out other causes of dwarfism
Specialist notes
Differential diagnosis with the desired chondrodysplasia of short-legged breeds (FGF4 retrogene insertion on CFA18, not associated with disease), with osteochondrodysplasia due to SLC13A1 deletion in the Miniature Poodle, with skeletal dysplasia 2 (COL11A2) in the Labrador and with spondylocostal dysostosis in the Miniature Schnauzer. Radiographs guide and the genetic test confirms. In humans, PCYT1A variants cause spondylometaphyseal dysplasia with cone-rod dystrophy; in affected Vizslas no manifest ocular phenotype has been described.
References
1. Rudd Garces G et al. (2021) PRKG2 splice site variant in Dogo Argentino dogs with disproportionate dwarfism. Genes (Basel) 12:1489. PMID: 34680883
2. Ludwig-Peisker O et al. (2022) PCYT1A missense variant in Vizslas with disproportionate dwarfism. Genes (Basel) 13:2354. PMID: 36553621
2. Ludwig-Peisker O et al. (2022) PCYT1A missense variant in Vizslas with disproportionate dwarfism. Genes (Basel) 13:2354. PMID: 36553621