Xoloitzcuintli
Only 8 Xoloitzcuintlis have been tested for carrier variants (Donner 2023), too few to say what the breed carries. 20 dogs stand behind the atlas figures here, so treat this page as an early sketch.
Also known as Mexican Hairless Dog, Xolito, Xolo, and Xoloescuincle.
What genetic diseases do Xoloitzcuintlis carry?
From a panel of 250 Mendelian-disease variants screened in 1,054,293 dogs (Donner et al. 2023), Xoloitzcuintlis carry one of them at observable frequency. Carrier frequency 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.
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.
What these results mean for a Xoloitzcuintli
SLC7A9 p.A217T (sold as a cystinuria test)
Marker disputed6.3% of Xoloitzcuintlis in the Donner 2023 cohort carried it (n=8).
- 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.
Other names
The Xoloitzcuintli is also recorded as Mexican Hairless Dog, Xolito, Xolo, Xoloescuincle, Xoloitzcuintle, and Xoloitzquintle.
Identified as Xoloitzcuintli (VBO:0201436) in the Vertebrate Breed Ontology (Mullen et al. 2025, CC-BY 4.0) · registry IDs FCI 234 · iDog 261 · VeNom 14434.
For researchers Population genetics, disease models and every recorded condition Open the research detail for the Xoloitzcuintli
In the atlas, the Xoloitzcuintli clusters consistently as Xoloitzcuintli (100% of the 20 dogs here). Genetic diversity is high (mean heterozygosity 0.3567), reflecting either a mixed-breed cluster or breeds with broad genetic backgrounds.
Ranks 92 of 107 on the bottleneck severity scale, in the upper quartile of genetic diversity. Mean heterozygosity is 0.357, notably high, indicates broad genetic background. Low breed predictability score (0.25), individual dogs of this breed vary widely in genetics, suggesting active substructure or sub-population diversity. Only 20 dogs of this breed in the atlas, modestly sampled.
Median lifespan is 14.0 years, about 1.9 years longer than a typical dog of 17.5 kg, an unusually positive longevity for this size.
What the atlas genotypes say about Xoloitzcuintli
Computed from the 14,478 CanVAS dogs in the Atlas, on an imputed genotype backbone: 77,215 directly typed sites per dog, imputed to 9.67 million variants.
The confidence below counts dogs, not reads: it is the size of the sample, and it is separate from how the genotypes were measured.
What does genetic diversity mean?
How varied a breed's gene pool is — the share of gene spots where a typical dog of the breed carries two different versions rather than two identical ones.
How to read it: Higher = more diverse. Among well-sampled breeds it ranges roughly 0.22 (least diverse) to 0.33 (most diverse).
Diversity is a strength, not a verdict on any individual dog. Lower diversity means it's worth paying attention to recessive-risk testing — not that a dog is doomed.
What does within-breed variation mean?
How much individual dogs within the breed differ from each other genetically.
How to read it: Higher = more internal variety among individuals of the breed.
Sensitive to how many dogs of the breed we've sampled.
Xoloitzcuintlis are a natural model for human disease
Because the same genes cause the same conditions across species, the inherited conditions documented in Xoloitzcuintlis help researchers understand, and work toward treating, the human diseases they model. This is the dog advancing human medicine. The breed models the human disease; it does not have it, and this is not a prediction for your dog.
- OMIM:120450, modeled by the breed's Comedo syndrome , the same underlying biology.
- OMIM:305100, modeled by the breed's Ectodermal dysplasia , the same underlying biology.
Every condition recorded in the Xoloitzcuintli
Beyond the testable carriers above, OMIA's literature catalogue records 2 genetic conditions in the Xoloitzcuintli, 2 of which have a known human equivalent. This is the documented landscape across all Xoloitzcuintlis ever studied, not a prediction for any one dog.
- Human equivalent: OMIM:120450
- Ectodermal dysplasia Autosomal incomplete dominantHuman equivalent: OMIM:305100
Where every number on this page came from.
This page draws on three primary data sources. Carrier frequencies for the Mendelian section come from Donner et al. 2023 (CC-BY-4.0). We grade these data at evidence Limited because the cohort is a direct-to-consumer ascertainment, which biases toward owners who chose to test their dogs. The panel also uses tag-SNP proxies for some variants rather than direct causal-variant assays. Limited is a study-design grade, not a quality grade: the Donner cohort is the largest open canine-genotype dataset in existence and we are grateful for it. We rate the confounding MEDIUM.
Population-genetic dimensions (heterozygosity, intra-breed PCA distance, nearest neighbors, trait-locus frequencies) come from CanVAS (Brundage 2026), harmonized through the Sniff Atlas. The exact release date and verification commit are pinned at the bottom of the page so a researcher can trace a number back to a specific snapshot. The disease-gene-variant graph comes from OMIA (Online Mendelian Inheritance in Animals; Nicholas, Tammen, and the Sydney Informatics Hub at the Sydney School of Veterinary Science, The University of Sydney; retrieved April 2026, DOI 10.25910/2AMR-PV70).
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. The computed dimensions on this page are derived from the open Sniff Atlas v1.0.1 (Gehring 2026, doi:10.5281/zenodo.20566358, CC-BY 4.0). Full citation formats including BibTeX, RIS, and CITATION.cff at sniff.world/cite.
Some things about living with a xoloitzcuintli never make it into a database. Add what you know as a Keeper, in your words →
Lived experience, kept beside the science.We have 20 xoloitzcuintlis. We do not have yours.
Every xoloitzcuintli added sharpens the breed's genetic neighborhood. Enrollment is free. The data stays open. The star is permanent.
- 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).