Multi-disease genetic panel for the Labradoodle (Labrador × Poodle cross) that groups together nine molecular tests: two forms of progressive retinal atrophy (prcd-PRA and rcd4-PRA), exercise-induced collapse (EIC), skeletal dysplasia 2/dwarfism (SD2), neonatal encephalopathy with seizures (NEWS), von Willebrand disease type 1 (vWD1), degenerative myelopathy (DM exon 2), centronuclear myopathy (CNM) and hereditary nasal parakeratosis (HNPK). The panel brings together variants described in both the Labrador Retriever and the Poodle, reflecting the hybrid origin of the breed. The molecular test is complementary to ocular, neuromuscular and haemostatic examination in breeding selection.

Applicable breed: Labradoodle (Labrador Retriever × Poodle cross). The variants come from the parental breeds and there are no published estimates of carrier frequency in the Labradoodle breeding population (limited data). prcd-PRA and rcd4-PRA are documented in the Poodle; EIC, CNM, SD2 and HNPK are documented in the Labrador; DM exon 2 is widely distributed. vWD1 due to VWF c.7437G>A is documented in the Miniature Poodle and other breeds (OMIA:001057-9615), but there is no breed-specific study in the Labradoodle; its real relevance in the breed is uncertain. In large cohorts, prcd-PRA remains one of the most frequent recessive variants in breeds of retriever and poodle ancestry (Donner et al., 2023; Clark et al., 2023).

- Reduced night vision and progressive retinal atrophy (prcd-PRA and rcd4-PRA)\n- Progressive blindness with altered ocular fundus\n- Weakness after intense exercise with wobbly gait and collapse (EIC)\n- Rapid recovery when exercise stops (EIC)\n- Short limbs and dwarf conformation (SD2)\n- Seizures and neurological deterioration in the neonatal puppy (NEWS)\n- Early death in most cases (NEWS)\n- Prolonged bleeding after surgery or trauma, ecchymoses and epistaxis (vWD1)\n- Progressive paresis of the hindlimbs with proprioceptive ataxia (DM)\n- Muscle weakness and atrophy from a young age with wobbly gait (CNM)\n- Nasal hyperkeratosis with fissures and nasal crust (HNPK)

The tests in the panel were developed independently as canine genetics groups characterised specific variants for each disease. prcd-PRA was associated with the PRCD gene (Zangerl et al., 2006). rcd4-PRA was associated with a frameshift mutation in C2orf71/PCARE, described in the Gordon Setter and Irish Setter (Downs et al., 2013) and later documented in the Standard and Miniature Poodle and other breeds (Downs et al., 2014; OMIA:001575-9615). Exercise-induced collapse was associated with DNM1 in the Labrador Retriever (Patterson et al., 2008). Skeletal dysplasia 2 (SD2) was associated with COL11A2 in the Labrador (Frischknecht et al., 2013). Neonatal encephalopathy with seizures of the Standard Poodle (NEWS) was associated with ATF2 (Chen et al., 2008). vWD type 1 is associated with the VWF c.7437G>A variant, described in the Doberman and in more than a dozen breeds (Crespi et al., 2018; OMIA:001057-9615). Centronuclear myopathy (CNM) of the Labrador was associated with a SINE insertion in HACD1 (formerly PTPLA) (Pelé et al., 2005; Maurer et al., 2012). Hereditary nasal parakeratosis (HNPK) of the Labrador was associated with SUV39H2 (Jagannathan et al., 2013). Canine DM was linked to the exon 2 variant of SOD1 (Awano et al., 2009).

- Genotype breeding animals before mating; the panel covers nine conditions in a single sample\n- For the recessive conditions (prcd-PRA, rcd4-PRA, EIC, SD2, NEWS, CNM, HNPK, DM): do not mate two carriers — 25% risk of homozygotes; carrier × clear is safe for offspring intended for breeding if they are tested\n- For DM: remember the incomplete penetrance; homozygotes are not a breeding priority and a clinical decision must not be based on genotype alone\n- For vWD1 (VWF c.7437G>A; dominant expression with incomplete penetrance): assess the von Willebrand factor level and confirm with the laboratory the exact variant used in the panel\n- After a confirmed clinical case, do not repeat the parental mating and inform the buyer of the status

The two PRAs in the panel differ by age of onset and ocular fundus, but the molecular diagnosis is what confirms the suspicion; rcd4-PRA is due to C2orf71/PCARE and not to CNGB3. Complementary annual ocular examination (ECVO/CERF). EIC must be differentiated from collapse due to arrhythmogenic cardiomyopathy, laryngeal myopathy and adynamic crisis. NEWS must be differentiated from other neonatal encephalopathies (infectious, metabolic, toxic). vWD1 is confirmed by assay of von Willebrand factor antigen and activity; the panel variant (VWF c.7437G>A) is documented in the Miniature Poodle, but not specifically in the Labradoodle. CNM is confirmed by muscle biopsy (centronuclear fibres) and molecular test. HNPK is confirmed by clinical examination and molecular test. DM is a diagnosis of exclusion: rule out spinal cord compression before attributing the presentation to SOD1.

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3. Downs LM, et al. Genetic screening for PRA-associated mutations in multiple dog breeds shows that PRA is heterogeneous within and between breeds. Vet Ophthalmol. 2014. PMID: 24255994.
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8. Pelé M, et al. 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. 2005. PMID: 15829503.
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10. Jagannathan V, et al. A mutation in the SUV39H2 gene in Labrador Retrievers with hereditary nasal parakeratosis (HNPK). PLoS Genet. 2013. PMID: 24098150.
11. Awano T, et al. Genome-wide association analysis reveals a SOD1 mutation in canine degenerative myelopathy. PNAS. 2009. PMID: 19188595.
12. Donner J, et al. Genetic prevalence and clinical relevance of canine Mendelian disease variants in over one million dogs. PLoS Genet. 2023. PMID: 36848397.
13. Clark JA, et al. Global frequency analyses of canine prcd-PRA and collie eye anomaly. Genes (Basel). 2023. PMID: 38003037.
14. Goossens LT, et al. Retrospective evaluation of hereditary eye diseases in Labradoodles. Front Vet Sci. 2026. PMID: 42339098 (contexto oftalmológico; no aborda rcd4/C2orf71).
OMIA:001575-9615 (rcd4/C2orf71); OMIA:001057-9615 (vWD1); OMIA:001466-9615 (EIC); OMIA:001772-9615 (SD2); OMIA:001374-9615 (CNM); OMIA:001373-9615 (HNPK).