Test Detail

Multi-disease panel for the Giant Schnauzer grouping five molecular tests: two forms of progressive retinal atrophy (NECAP1-PRA and prcd-PRA), dilated cardiomyopathy (DCM due to a 22-bp deletion in RBM20), hyperuricosuria (HUU, SLC2A9) and degenerative myelopathy (DM, exon 2 variant of SOD1). It combines ocular, cardiac, urinary and neurological conditions. Molecular testing is complementary to, not a substitute for, annual ocular examination and cardiac monitoring in breeding selection.

Applicable breed: Giant Schnauzer. RBM20-related DCM: in the Standard Schnauzer ~21 % carried at least one allele (19.7 % heterozygotes; 1.5 % homozygotes) and in the Giant Schnauzer 9.8 % (Leach 2022); the variant was not detected in the other breeds analysed. HUU is described in the Giant Schnauzer at low frequencies (Karmi et al., 2010; frequency by breed: Karmi et al., 2010, J Vet Intern Med, PMID: 21054540). prcd-PRA and DM are pan-breed tests without published breed-specific evidence in the Giant Schnauzer; NECAP1-PRA has scant casuistry. Reliable carrier frequencies in the breeding population: limited data.

- Genotype breeding animals before mating; the panel covers five conditions in a single sample\n- Recessive conditions (NECAP1-PRA, prcd-PRA, HUU, DM): do not cross two carriers (25 % affected homozygotes); carrier x clear is admissible if the offspring intended for breeding is tested\n- DCM (RBM20): do not use homozygotes as breeding animals and consider echocardiography and Holter in breeding animals, in addition to molecular testing\n- HUU: in homozygotes, low-purine diet, abundant hydration and urinary monitoring\n- After a confirmed clinical case, do not repeat the parental cross and communicate the status to the buyer

Annual ocular examination (ECVO) and electroretinography when appropriate: several PRAs are late-onset. DCM requires diagnosis by echocardiography and Holter; molecular testing does not replace cardiac monitoring, and the RBM20 variant does not explain all cases of DCM in the breed. HUU is confirmed by urinalysis and, if there are stones, by stone analysis (differentiate from cystine and infectious ones). DM is a diagnosis of exclusion (rule out spinal cord compression, disc herniation and tumours).

1. NECAP1-PRA: Hitti RJ et al. 2019. Whole genome sequencing of Giant Schnauzer dogs with progressive retinal atrophy establishes NECAP1 as a novel candidate gene. Genes (Basel). PMID: 31117272; Kang M et al. 2025. PCR-based detection of hereditary mutations in SLC2A9, BTBD17, and NECAP1 among native Korean dog breeds. J Vet Sci. PMID: 40765230; OMIA:002198-9615
2. prcd-PRA: Zangerl B et al. 2006. Identical mutation in a novel retinal gene causes progressive rod-cone degeneration in dogs. Genomics. PMID: 16938425; Goldstein O et al. 2006. Linkage disequilibrium mapping in domestic dog breeds. Genomics. PMID: 16859891
3. DCM (RBM20): Harmon MW et al. 2017. Dilated cardiomyopathy in Standard Schnauzers: retrospective study of 15 cases. J Am Anim Hosp Assoc. PMID: 27841675; Leach SB et al. 2022. Prevalence, geographic distribution, and impact on lifespan of a dilated cardiomyopathy-associated RBM20 variant in genotyped dogs. J Vet Cardiol. PMID: 34144877; OMIA:002365-9615 (Leach 2014: ponencia ACVIM, sin PMID)
4. HUU (SLC2A9): Bannasch D et al. 2008. Mutations in the SLC2A9 gene cause hyperuricosuria and hyperuricemia in the dog. PLoS Genet. PMID: 18989453; Karmi N et al. 2010. Validation of a urine test and characterization of the putative genetic mutation for hyperuricosuria. Am J Vet Res. PMID: 20673090; Karmi N et al. 2010. Estimated frequency of the canine hyperuricosuria mutation in different dog breeds. J Vet Intern Med. PMID: 21054540; OMIA:001033-9615
5. DM (SOD1): Awano T et al. 2009. Genome-wide association analysis reveals a SOD1 mutation in canine degenerative myelopathy. Proc Natl Acad Sci U S A. PMID: 19188595; Coates JR et al. 2010. Canine degenerative myelopathy. Vet Clin North Am Small Anim Pract. PMID: 20732599; OMIA:000263-9615