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PCYT1A Missense Variant in Vizslas with Disproportionate Dwarfism
Odette Ludwig-Peisker1, Emily Ansel2, Daniela Schweizer3
1Institute of Genetics, Vetsuisse Faculty, University of Bern, 3001 Bern, Switzerland.
Genes
|December 23, 2022
Summary
Researchers identified a genetic cause for disproportionate dwarfism (skeletal dysplasia 3) in Vizsla dogs, linked to the PCYT1A gene. This finding aids in genetic testing to prevent affected puppies.
Area of Science:
- Genetics
- Veterinary Medicine
- Comparative Genomics
Background:
- Disproportionate dwarfism is a heterogeneous group of skeletal dysplasias observed in various species, including dogs.
- Vizsla dogs exhibit a distinct form of disproportionate dwarfism, proposed as skeletal dysplasia 3 (SD3), characterized by limb bone deformities.
Purpose of the Study:
- To identify the genetic basis of disproportionate dwarfism (SD3) in Vizsla dogs.
- To investigate the role of the PCYT1A gene in canine skeletal dysplasia.
Main Methods:
- Pedigree analysis and combined linkage and homozygosity mapping were employed to localize the genetic defect.
- Whole-genome sequencing of affected dogs and comparison with control genomes identified candidate variants.
- Genotyping was performed on affected and unaffected dogs to confirm genotype-phenotype association.
Main Results:
- A single, private protein-changing variant (PCYT1A:c.673T>C) in the PCYT1A gene was identified within a ~4 Mb critical interval on chromosome 33.
- This variant perfectly co-segregated with the SD3 phenotype in the studied Vizsla family.
- While one case of potential heterogeneity was noted, 130 other Vizslas showed perfect genotype-phenotype association, with no unaffected dogs being homozygous for the mutant allele.
Conclusions:
- A PCYT1A missense variant is proposed as the causative mutation for skeletal dysplasia 3 (SD3) in Vizsla dogs.
- The identified skeletal changes in Vizslas are comparable to human spondylometaphyseal dysplasia with cone-rod dystrophy (SMD-CRD), also linked to PCYT1A loss-of-function.
- Genetic testing for the PCYT1A variant can facilitate the prevention of breeding affected Vizsla puppies.
Keywords:
Canis lupus familiarisanimal modelchondrodysplasiadogmorphologyprecision medicineskeletal dysplasiaskeletonMore Related Videos
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