Skip to main content
snıff
Canine Mendelian disease record

Neuronal Ceroid Lipofuscinosis 7 (Discovered in the Chinese Crested Dog and Chihuahua; NCL7)

Neuronal Ceroid Lipofuscinosis 7 (Discovered in the Chinese Crested Dog and Chihuahua; NCL7). 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:001962-9615
Autosomal recessive
Source dataset
Sniff Atlas v1.0.1 / DOI
The human connection

A model of human neuronal ceroid lipofuscinosis 7

This is the canine counterpart of neuronal ceroid lipofuscinosis 7 in people. That makes affected dogs a naturally-occurring model of the human disease, and it is part of why studying dogs moves medicine forward for everyone. It does not mean your dog has the human disease. It means the two share an underlying biology.

In people, the disease is described as: Neuronal ceroid lipofuscinosis 7 (CLN7-NCL) is a rare condition that affects the nervous system. Signs and symptoms of the condition generally develop in early childhood (average age 5 years) and may include loss of muscle coordination (ataxia), seizures that do not respond to medications, muscle twitches (myoclonus), visual impairment, and developmental regression (the loss of previously acquired skills). CLN7-NCL is caused by changes (mutations) in the MFSD8 gene and is inherited in an autosomal recessive manner. Treatment options are limited to therapies that can help relieve some of the symptoms.

In humans it is also called: CLN7, ceroid lipofuscinosis, neuronal, 7, ceroid lipofuscinosis, neuronal, type 7, CLN7 disease, CLN7 disease, late infantile.

MONDO:0012588 OMIM 610951

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 2026-06-03.

Summary

One of several variants of neuronal ceroid lipofuscinosis (NCL) or Batten disease: CLN7; NCL7

Clinical features

Guo et al. (2015): "progressive neurological decline that included blindness, anxiety, and cognitive impairment. A diagnosis of neuronal ceroid lipofuscinosis was made based on neurological signs, magnetic resonance imaging of the brain, and fluorescence microscopic and electron microscopic examination of brain sections". Similar clinical signs were also observed in Chihuahuas (Faller et al. 2016).
Rietmann et al. (2024) "investigated two Small Swiss Hound littermates that showed progressive ataxia and loss of cognitive functions and vision starting around the age of 12 months. Both dogs had to be euthanized a few months after the onset of disease owing to the severity of their clinical signs."

Molecular genetics

Small deletion (omia.variant:551): "c.843delT is predicted to cause a frame shift and premature stop codon resulting in a truncated protein, MFSD8:p.F282Lfs13*, missing its 239 C-terminal amino acids" in the Chinese Crested breed (Guo et al., 2015). Faller et al. (2016) demonstrated that the same genetic variant is also present in Chihuahuas with neuronal ceroid lipofuscinosis 7. Karli et al. (2016) reported that "the MFSD8:c.843delT [omia.variant:551]variant is also present [and causal] in Chihuahuas without official registrations." Ashwini et al. (2016) also reported the same likely causal mutation in Chihuahuas.
Rietmann et al. (2024) conducted whole genome sequencing of an affected Small Swiss Hound and identified a 18 819 bp duplication (omia.variant:1754) within the MFSD8 gene as likely causal variant. 

Pathology

"Both the cerebellum and the cerebral cortex exhibited massive intracellular accumulations of autofluorescent material with a golden yellow emission under blue light illumination . . . . In the cerebellum storage material was most prominent in the Purkinje cells, but substantial amounts of this material were also present in the granular layer . . . . Perinuclear accumulations of autofluorescent storage granules were observed in neurons throughout the cerebral cortex" (Guo et al., 2015) The pathology of affected Chihuahuas was described by Faller et al. (2016).
Rietmann et al. (2024): "Pathological investigation of one affected [Small Swiss Hound] dog revealed cerebral and cerebellar atrophy with cytoplasmic accumulation of autofluorescent material in degenerating neurons." 

Prevalence

Pervin et al. (2022) investigated the c.846delT allele in 1007 Chihuahuas in Japan and identified a "carrier rate of 1.29%, indicating a mutant allele frequency (0.00645)".

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 610951 Gene · OMIM 611124

Source: OMIA (Nicholas, Tammen & the Sydney Informatics Hub), entry OMIA:001962-9615, doi:10.25910/2AMR-PV70 (CC-BY 4.0).

Signs & cross-references

How it presents

Catalogued in the Mondo disease ontology (the cross-species disease identity used by the Monarch Initiative) as neuronal ceroid lipofuscinosis 7 (MONDO:0012588).

Phenotype terms: Human Phenotype Ontology + Mammalian Phenotype Ontology; disease terms: Mondo (Monarch Initiative). Cross-references curated by OMIA (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 10.

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 Neuronal Ceroid Lipofuscinosis 7 (Discovered in the Chinese Crested Dog and Chihuahua; NCL7) 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 Neuronal Ceroid Lipofuscinosis 7 (Discovered in the Chinese Crested Dog and Chihuahua; NCL7) 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%1%2%
Chihuahua0.14% · n 4,271
Beagle<0.1% · n 5,292
n = 9,563 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 Neuronal Ceroid Lipofuscinosis 7 (Discovered in the Chinese Crested Dog and Chihuahua; NCL7) is measured; phenotype outcome depends on penetrance and modifiers.
▸ Full table with Wilson 95% confidence intervals
Breed Carrier frequency n tested
Chihuahua 0.14% 4,271
Beagle <0.1% 5,292

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:001962-9615.

  • 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:001962-9615 · Donner et al. 2023