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Canine Mendelian disease record

Xanthinuria, Type 1 (Discovered in mixed breed dogs)

Xanthinuria, Type 1 (Discovered in mixed breed dogs). Autosomal recessive. Observed in 0 of 266 breeds tested in the Sniff Atlas, with measured variant frequencies drawn from 242,665 dogs (Donner 2023). Whether a dog carrying this variant is at risk depends on the disease’s inheritance pattern; outcome also depends on penetrance, modifiers, and environment. The frequencies below describe variant prevalence, not confirmed disease incidence.

OMIA identifier
OMIA:002445-9615
Autosomal recessive
Source dataset
Sniff Atlas v1.0.1 / DOI
The human connection

A model of human xanthinuria type I

This canine condition is studied as a natural model of xanthinuria type I in people; it is not the same as a human xanthinuria type I diagnosis. Studying dogs can move medicine forward for everyone; the canine disease remains the subject.

In people, the disease is described as: A rare autosomal recessive disorder of purine metabolism characterized by the isolated deficiency of xanthine dehydrogenase, causing hyperxanthinemia with low or absent uric acid and xanthinuria, leading to urolithiasis, hematuria, renal colic and urinary tract infections, while some patients are asymptomatic and others suffer from kidney failure. Less common manifestations include arthropathy, myopathy and duodenal ulcer.

In humans it is also called: XAN1, isolated xanthine oxidase deficiency, type 1 xanthinuria, xanthinuria type 1, xanthinuria, type 1.

MONDO:0010209 OMIM 278300

Mapped from OMIA via the human disease's OMIM entry to the Mondo Disease Ontology (Monarch Initiative, CC-BY 4.0). Sniff renders this as a model-of link; the canine disease remains the subject of this page.

About this disease

From OMIA's curated record

Documented in OMIA (Online Mendelian Inheritance in Animals). This describes the disease as recorded in the published literature, not a prediction for any individual dog. As of 2026-08-27.

Summary

Animals with hereditary xanthinuria (excretion of large amounts of xanthine in the urine) may be asymptomatic, may have subclinical uroliths (xanthine stones), or present with clinical signs of urolithiasis. Urolith formation can be influenced by other biologic and environmental factors such as sex, diet and urine properties. Xanthinuria, type I (OMIA:002445) is caused by variation in the XDH gene and xanthinuria, type II (OMIA:001819) is caused by variation in the MOCOS gene. Information relating to xanthinuria without identified causal variants is listed under xanthinuria, generic (OMIA:001283).

Molecular genetics

Furrow et al. (2016) reported in a conference abstract the identification of three likely disease-causing mutations for xanthine urolithiasis. Affected Cavalier King Charles Spaniels had a mutation resulting in a premature stop codon in the molybdenum cofactor sulfurase gene (MOCOS), affected Toy Manchester Terriers had a splice site mutation in MOCOS, and an affected mixed breed dog had a splice site mutation in the xanthine dehydrogenase (XDH) gene. These findings were included in the publication by Tate et al. (2021). Tate et al. (2021): "The aim of this study was to uncover variants underlying risk for xanthinuria in dogs. Affected dogs included two Manchester Terriers, three Cavalier King Charles Spaniels, an English Cocker Spaniel, a Dachshund, and a mixed-breed dog. ...Sanger sequencing of [candidate genes] XDH and MOCOS identified four putative causal variants ... : an XDH c.654G > A splice site variant that results in skipping of exon 8 (mixed-breed dog), a MOCOS c.232G > T splice site variant that results in skipping of exon 2 (Manchester Terriers), a MOCOS p.Leu46Pro missense variant (Dachshund), and a MOCOS p.Ala128Glyfs*30 frameshift variant that results in a premature stop codon (Cavalier King Charles Spaniels and English Cocker Spaniel). ... All variants were found in a homozygous state in the affected dogs, consistent with an autosomal recessive mode of inheritance."

Prevalence

The c.654G>A variant was not present in 813 dog sequences included in the Dog Biomedical Variant Database Consortium (Jagannathan et al., 2019).

Human analog

OMIA links this condition to its human counterpart in OMIM (Mendelian Inheritance in Man), the place to read across to the deeper human literature for the same biology.

Disease · OMIM 278300 Gene · OMIM 607633

Source: OMIA (Nicholas, Tammen & the Sydney Informatics Hub), entry OMIA:002445-9615, doi:10.25910/2AMR-PV70 (CC-BY 4.0).

OMIA curates the disease definition, the clinical description and the reference list. The cross-species disease identity is Monarch's. Sniff renders these and adds the breed-level frequencies, the plain-language summary, and a stated reason wherever a number is missing.

The evidence

Published references

The peer-reviewed papers behind this disease, curated by OMIA. Starred entries are OMIA-designated landmark papers.

  1. Multiple variants in XDH and MOCOS underlie xanthine urolithiasis in dogs. · Mol Genet Metab Rep · 2021 · PMID 34584846

References curated by OMIA (Nicholas, Tammen & the Sydney Informatics Hub), doi:10.25910/2AMR-PV70 (CC-BY 4.0). Full list at the OMIA entry.

Your breed

See what Xanthinuria, Type 1 (Discovered in mixed breed dogs) looks like in your dog's breed.
Variant frequency by breed

Observed only in small-sample breeds

Maximum variant frequency per breed across variants in the Donner 2023 cohort, with . The list below is split into well-sampled breeds (n ≥ 50 tested) and small-sample breeds (n < 50, where the Wilson CI typically spans more than 20 percentage points and frequencies should not be compared directly to the well-sampled entries). Frequencies are population-level, not per-litter or per-line.

Scope of this record

Scope

This record carries the breed-level carrier frequencies from the Donner 2023 cohort. Penetrance data (the fraction of at-risk dogs that develop the phenotype) is not yet quantified for this disease in the Sniff Atlas v1.0.1. The OMIA entry is the authoritative reference for the clinical phenotype, inheritance pattern, and gene assignment.

Predicted disease relevance at the per-dog level is UNPROVEN. The variant frequency is measured; phenotype outcome depends on penetrance, environment, and modifier loci. Consult a veterinarian for clinical interpretation.

How to cite this record

Citations

If you use this record in published work, cite the Sniff Atlas (the published dataset that carries the breed-level carrier frequencies) and the upstream sources:

  • Sniff Atlas v1.0.1 for the per-breed carrier frequencies:

    Gehring, M. (2026). Sniff Atlas v1.0.1. Zenodo. https://doi.org/10.5281/zenodo.20566358. CC-BY 4.0.

  • OMIA for the disease definition, inheritance, and gene assignment:

    Nicholas, F. W., & Tammen, I. (2024). OMIA. Sydney Informatics Hub, The University of Sydney. https://doi.org/10.25910/2AMR-PV70. Entry: OMIA:002445-9615.

  • Donner et al. 2023 for the breed × variant carrier-frequency cohort:

    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. https://doi.org/10.1371/journal.pgen.1010651.

Full citation formats (BibTeX, RIS, CITATION.cff) at sniff.world/cite.

Related

Related

Last updated
Sources: Sniff Atlas v1.0.1 · OMIA OMIA:002445-9615 · Donner et al. 2023