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Canine Mendelian disease record

Hypomyelination (Discovered in the Weimaraner)

Hypomyelination (Discovered in the Weimaraner). Autosomal recessive. Observed in 2 of 266 breeds tested in the Sniff Atlas, with measured carrier frequencies drawn from 242,662 dogs (Donner 2023). Per-dog phenotype outcome depends on penetrance, modifiers, and environment; the carrier frequencies below describe variant prevalence, not disease incidence.

OMIA identifier
OMIA:000526-9615
Autosomal recessive
Source dataset
Sniff Atlas v1.0.1 / DOI
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 2026-06-03.

Clinical features

Affected animals present with generalised tremors at about 2 to 3 weeks of age (Kornegay et al., 1987; Pemberton et al., 2014). Clinical signs gradually resolve in most dogs by 3 to 4 months of age (Kornegay et al., 1987; Pemberton et al., 2014), "though some dogs retained a persistent fine tremor of the hind limbs" (Pemberton et al., 2014). Pemberton et al. (2014) suggest that hyppomyelination previously described in Chow Chow dogs (Vandevelde and Braund, 1981; Vandevelde et al., 1978) is identical to the disease in Weimaraner dogs.

Molecular genetics

After sequencing the most obvious candidate gene in the candidate region (see Mapping section) and discovering no mutations, Pemberton et al. (2014) sequenced all 199 exons of the remaining 16 genes in that region, yielding 54 variants, only one of which had the potential to be deleterious. This variant turned out to be the causal mutation: "a deletion of a single A nucleotide within exon 9 of the gene encoding folliculin-interacting protein 2 (FNIP2). This mutation at nucleotide 880 of the coding sequence (c.880delA, XM_532705) causes a frameshift, and the amino acid sequence is altered beginning at codon 294, with a premature translation stop signal introduced at codon 296 . . . . A highly truncated protein of 295 amino acids compared with the wild-type protein of 1,106 amino acids is predicted to result from this p.Ile294fsX296 mutation"

Pathology

Kornegay et al., (1987) "Many axons in the brain and spinal cord were either thinly myelinated or nonmyelinated in the affected dogs relative to the controls, while the peripheral nervous system was normally myelinated. The degree of hypomyelination seemed particularly severe at the periphery of the lateral and ventral funiculi of the spinal cord. In all areas of white matter evaluated, astrocytes subjectively outnumbered oligodendrocytes in the [affeted] Weimaraners ..."

Human analog

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

Gene · OMIM 612768

Source: OMIA (Nicholas, Tammen & the Sydney Informatics Hub), entry OMIA:000526-9615, doi:10.25910/2AMR-PV70 (CC-BY 4.0).

The evidence

Published references

The peer-reviewed papers behind this disease, curated by OMIA. Starred entries are OMIA-designated landmark papers. Showing 6 of 8.

  3. Hypomyelination in three Weimaraner dogs. · J Small Anim Pract · 2010 · PMID 20973788
  4. Weakness associated with spinal subpial myelopathy in a Weimaraner puppy. · Journal of Small Animal Practice · 1988
  5. Hypomyelination in Weimaraner dogs. · Acta Neuropathol · 1987 · PMID 3577694
  6. Dysmyelination in Chow Chow dogs: further studies in older dogs. · Acta Neuropathol · 1981 · PMID 7315204

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.

Predict a litter

Set each parent's status for Hypomyelination (Discovered in the Weimaraner) and see the odds for their puppies. Single recessive variant, exact Mendelian math.

Parent A
Parent B
NNClear
NmCarrier
NmCarrier
mmAffected
Clear25%
Carrier50%
Affected25%

These are the genetic odds for one known variant, not a promise: a real litter varies around them, and penetrance or other genes can change whether the condition ever appears. Use it to avoid pairing two carriers and to keep a line healthy, not to engineer a dog. Inheritance mode per OMIA.
Your breed

See what Hypomyelination (Discovered in the Weimaraner) looks like in your dog's breed.
Carrier frequency by breed

Top 2 well-sampled breeds (n ≥ 50)

Maximum 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.

0%3%5%
Weimaraner0.93% · n 647
Labrador Retriever<0.1% · n 16,854
n = 17,501 dogs · Donner et al. 2023 carrier-screening cohort · Sniff Atlas
Each bar is one well-sampled breed; the whisker is its Wilson 95% CI, and fainter bars have wider intervals. Frequencies are population-level, not per-litter. Carrier status for Hypomyelination (Discovered in the Weimaraner) is measured; phenotype outcome depends on penetrance and modifiers.
▸ Full table with Wilson 95% confidence intervals
Breed Carrier frequency n tested
Weimaraner 0.93% 647
Labrador Retriever <0.1% 16,854

264 additional breeds in the Donner 2023 cohort were tested but showed no carriers.

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 carrier 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:000526-9615.

  • 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:000526-9615 · Donner et al. 2023