Test Detail

Multidisease genetic panel for the Labrador Retriever that groups ten molecular tests: exercise-induced collapse (EIC), GTPBP2-related progressive retinal atrophy (GTPBP2-PRA), retinal dysplasia/osteochondrodysplasia (OSD), centronuclear myopathy (CNM), hereditary nasal parakeratosis (HNPK), skeletal dysplasia or dwarfism (SD2), Stargardt disease (retinal degeneration, STGD), degenerative myelopathy (DM), pyruvate kinase deficiency (PK) and hyperuricosuria (HUU/SLC). Each condition has its own molecular basis and inheritance. The panel is complementary to the ocular, neuromuscular, haematological and orthopaedic examination in breeding selection.

Applicable breed: Labrador Retriever. The EIC, CNM, HNPK, SLC2A9 and PKLR variants are relatively common in breeding lines. GTPBP2-PRA and OSD have a lower caseload. Stargardt disease showed a high allele frequency in a Japanese study (0.246 in 120 Labradors), so it should not be considered rare. Reliable carrier frequencies are not published systematically (limited data).

- Weakness after intense exercise with staggering gait and collapse (EIC)
- Rapid recovery when exercise stops (EIC)
- Reduced night vision and progressive retinal atrophy (GTPBP2-PRA, Stargardt)
- Multifocal retinal lesions and impaired central vision (Stargardt)
- Retinal and skeletal conformation abnormalities from puppyhood (OSD)
- Muscle weakness and atrophy from a young age with staggering gait (CNM)
- Nasal hyperkeratosis with fissures and nasal crust (HNPK)
- Short limbs and dwarf conformation (SD2)
- Progressive hindlimb paresis with proprioceptive ataxia (DM)
- Chronic haemolytic anaemia with pale mucous membranes, lethargy and splenomegaly (PK)
- Urolithiasis from urate stones with urinary obstruction (HUU/SLC)

Exercise-induced collapse was associated with DNM1 (Patterson 2008). Oculoskeletal dysplasia (OSD) in the Labrador is due to COL9A3 (Goldstein 2010); skeletal dysplasia 2 (SD2) to COL11A2 (Frischknecht 2013) and hereditary nasal parakeratosis (HNPK) to SUV39H2 (Jagannathan 2013). GTPBP2-related progressive retinal atrophy was identified in 2025 (Murgiano) and canine Stargardt disease due to ABCA4 in 2019 (Mäkeläinen). Centronuclear myopathy (CNM) in the Labrador is due to an exonic insertion in PTPLA/HACD1 (OMIA:001374-9615; Pelé 2005), NOT to DNM1. Canine DM was linked to exon 2 of SOD1 (Awano 2009), Labrador PK to PKLR (Gultekin 2012) and hyperuricosuria to SLC2A9 (Bannasch 2008).

- Genotype breeding animals before mating; the panel covers ten conditions in a single sample
- For all conditions (recessive): do not mate two carriers — 25% risk of affected homozygotes; carrier×clear is safe for offspring intended for breeding if tested
- For DM: mutated homozygotes are not a breeding priority; carriers with clear animals
- For OSD: avoid mating two affected animals because of the possibility of more severe skeletal conditions
- After a confirmed clinical case, do not repeat the parental mating and inform the buyer of the status

EIC must be differentiated from collapse due to arrhythmogenic cardiomyopathy, laryngeal myopathy and adynamic crisis. CNM is due to PTPLA/HACD1 (OMIA:001374-9615) and is confirmed by muscle biopsy (centronuclear fibres) and molecular testing; do NOT confuse it with EIC or attribute it to DNM1. HNPK, PK and urate urolithiasis require their specific confirmation. DM is a diagnosis of exclusion: rule out spinal cord compression before attributing the condition to SOD1. Annual ocular examination (ECVO/CERF) is complementary.

1. Patterson EE et al. 2008. A canine DNM1 mutation is highly associated with the syndrome of exercise-induced collapse. Nat Genet. PMID: 18806795. 2. Murgiano L et al. 2025. GTPBP2 in-frame deletion in canine model with non-syndromic progressive retinal atrophy. Sci Rep. PMID: 39971978. 3. Goldstein O et al. 2010. COL9A2 and COL9A3 mutations in canine autosomal recessive oculoskeletal dysplasia. Mamm Genome. PMID: 20686772. 4. Pelé M et al. 2005. SINE exonic insertion in the PTPLA gene leads to multiple splicing defects and segregates with the autosomal recessive centronuclear myopathy in dogs. Hum Mol Genet. PMID: 15829503. 5. Jagannathan V et al. 2013. A mutation in the SUV39H2 gene in Labrador Retrievers with hereditary nasal parakeratosis. PLoS Genet. PMID: 24098150. 6. Frischknecht M et al. 2013. A COL11A2 mutation in Labrador retrievers with mild disproportionate dwarfism. PLoS One. PMID: 23527306. 7. Mäkeläinen S et al. 2019. An ABCA4 loss-of-function mutation causes a canine form of Stargardt disease. PLoS Genet. PMID: 30889179. 8. Awano T et al. 2009. Genome-wide association analysis reveals a SOD1 mutation in canine degenerative myelopathy. PNAS. PMID: 19188595. 9. Gultekin GI et al. 2012. Erythrocytic pyruvate kinase mutations causing hemolytic anemia, osteosclerosis, and secondary hemochromatosis in dogs. J Vet Intern Med. PMID: 22805166. 10. Bannasch D et al. 2008. Mutations in the SLC2A9 gene cause hyperuricosuria and hyperuricemia in the dog. PLoS Genet. PMID: 18989453. OMIA:001466-9615, OMIA:002926-9615, OMIA:001522-9615, OMIA:001374-9615, OMIA:001373-9615, OMIA:001772-9615, OMIA:002179-9615, OMIA:000263-9615, OMIA:000844-9615, OMIA:001033-9615.