Boerboel
The tested variant with the highest allele frequency is Canine Multifocal Retinopathy 1, at 30% among the 165 Boerboels tested (Donner 2023; gene copies, not dogs), then Cystinuria Type I-A (19%) and Hyperuricosuria (5.2%).
Which disease variants turn up in Boerboels?
From a panel of 250 Mendelian-disease variants screened in 1,054,293 dogs (Donner et al. 2023), 5 turn up in Boerboels at observable frequency. The figure beside each is its allele frequency. Of the gene copies tested in this breed, the share that carry the variant. Every dog carries two copies, so this is not the share of dogs. It is not clinical risk. Most recessive variants require two copies for disease expression; many dominant variants show incomplete penetrance. Read this as a population fingerprint of what's in the gene pool, not a per-dog prediction.
BEST1what this gene does
BEST1 is a gene that helps maintain the health of the retina, the light-sensitive layer at the back of the eye. It plays a role in keeping the cells in the retina functioning properly.
For your dog: If your dog is from a breed known to carry BEST1 variants, it’s worth discussing retinal health with your vet, especially if you notice any vision changes.
SLC3A1what this gene does
SLC3A1 is a gene that helps transport certain amino acids in the kidneys. It plays a key role in preventing the buildup of cystine, which can form stones.
For your dog: If your dog is from a breed known to carry SLC3A1 variants, it’s worth discussing cystinuria risks with your vet, especially if urinary issues arise.
SLC7A9what this gene does
SLC7A9 is a gene that helps transport certain amino acids in the kidneys. It plays a role in how the body handles cystine, an amino acid that can form crystals.
For your dog: If your dog is a carrier, it’s worth discussing with your vet to monitor urinary health and catch any issues early.
SLC2A9what this gene does
SLC2A9 is a gene that helps regulate uric acid levels in a dog's body. It plays a role in how the kidneys handle this substance.
For your dog: If your dog is one of the breeds known to carry this gene variant, it’s worth discussing with your vet to understand any potential urinary health concerns.
What these results mean for a Boerboel
19.1% of Boerboels in the Donner 2023 cohort carried it (n=165).
- The kidneys fail to reclaim an amino acid called cystine, which can form crystals and stones in the urine and block the urinary tract.
OMIA 000256-9615
“Cystinuria, type 1 - A is an inherited defect that causes failure of reabsorption of cystine in the proximal renal tubule, leading to cystine precipitation in the urine. Formation of crystals and calculi lead to urolithiasis and urinary tract obstruction.” OMIA 000256-9615
What to do
Straining to urinate, or passing little or no urine, needs a veterinarian the same day.
No test, or a mix
Without a test nobody can say how many copies a dog has.
SLC7A9 p.A217T (sold as a cystinuria test)
Marker disputed11.2% of Boerboels in the Donner 2023 cohort carried it (n=165).
- The curated record finds no support for this variant causing cystinuria, and the researchers who studied it advise against using it as a test.
OMIA 001880-9615
“there appears to be no support for the variant to be causal” OMIA 001880-9615
“strongly recommend not to use "the variant in SLC7A9 as a test to predict the risk of developing cystinuria in male English bulldogs.” OMIA 001880-9615
What to do
A carrier result for this variant does not predict bladder stones. Straining to urinate or blood in the urine is a reason to see a veterinarian whatever a DNA test says.
No test, or a mix
The curated record gives no reason to test for this variant.
For researchers Population genetics, disease models and every recorded condition Open the research detail for the Boerboel
Where every number on this page came from.
This page draws on one primary data source. Allele frequencies and sample sizes come from Donner et al. 2023 (CC-BY-4.0), a direct-to-consumer screening cohort, graded Limited as a study design because the dogs were tested at their owners' choice. No genotyped research dogs of this breed are in the three open releases the atlas reads, so the population-genetic sections other breed pages carry are absent here for that reason, not hidden. Conditions recorded for the breed come from OMIA.
What this page does not yet have. Inheritance modes and per-disease penetrance evidence from Donner 2023 are in the structured data for every variant the panel covers. Mondo, OMIM, Ensembl, and HGNC cross-references live on the gene and disease pages this page links to, rather than being repeated here. What is still absent from this breed page is anything not in the cited panel, and each such gap carries its cause where it appears.
How to cite this page. Cite Donner et al. 2023 (doi:10.1371/journal.pgen.1010651) for every frequency on this page, and OMIA for each condition, with the sample size shown beside the figure.
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- Donner J, Freyer J, Davison S, Anderson H, Blades M, Honkanen L, et al. (2023). Genetic prevalence and clinical relevance of canine Mendelian disease variants in over one million dogs. PLOS Genetics 19(2):e1010651. doi:10.1371/journal.pgen.1010651
- Brundage DM (2026). CanVAS: A Harmonized and Imputed Canine Variant Atlas. bioRxiv. doi:10.64898/2026.04.13.718238
- Nicholas, F.W., Tammen, I., & Sydney Informatics Hub. (2026). Online Mendelian Inheritance in Animals (OMIA) [dataset]. The University of Sydney. https://omia.org. doi:10.25910/2AMR-PV70 (retrieved April 2026).