Multi-disease genetic panel for the Golden Retriever that groups seven molecular tests: three forms of progressive retinal atrophy (GR-PRA1/SLC4A3, GR-PRA2/TTC8 and prcd-PRA/PRCD), Duchenne-type muscular dystrophy (DMD), congenital ichthyosis (PNPLA1), neuronal ceroid lipofuscinosis type 5 (NCL5/CLN5) and osteogenesis imperfecta (COL1A1). It combines ocular, neuromuscular, dermatological, metabolic and skeletal conditions. The panel is complementary to the ophthalmological, neurological and dermatological examination in breeding selection.

Golden Retriever worldwide. prcd-PRA and GR-PRA1/2 are the most frequent PRAs in the breed. Ichthyosis and NCL5 have documented frequencies. Carrier frequencies vary between countries and lines (limited data).

- GR-PRA1/GR-PRA2: progressive night blindness\n- prcd-PRA: initial night blindness with progression\n- MD: progressive muscle weakness, hypertrophy of the tongue\n- Ichthyosis: generalised scaling from birth\n- NCL5: ataxia and neurodegeneration\n- OI: recurrent fractures

The various conditions in the panel were characterised independently. The three PRAs (GR-PRA1, GR-PRA2 and prcd-PRA) have different genes and are independent of one another. MD is X-linked recessive. Congenital ichthyosis was associated with PNPLA1 (Grall 2012). NCL5 was associated with CLN5 in the Golden Retriever (Gilliam 2015). Osteogenesis imperfecta was associated with COL1A1.

- Genotype breeding animals before mating (seven tests on a single sample)\n- For the recessive conditions (GR-PRA1, GR-PRA2, prcd-PRA, NCL5, OI): do not mate two carriers — 25% of affected homozygotes; carrier×clear is safe if tested\n- For MD (X-linked): carrier females transmit the gene to 50% of their sons (which will be affected); do not breed from carrier females\n- For ichthyosis: do not mate two carriers\n- Complement with annual ophthalmological examination (ECVO) and neurological assessment\n- After a confirmed case, do not repeat the parental mating and inform the buyer of the status

The differential diagnosis of Golden Retriever PRAs requires differentiating the three forms by specific test: a negative result for one does not exclude the other two. MD is a diagnosis of exclusion after ruling out acquired neuromuscular causes. Ichthyosis is diagnosed by skin biopsy and molecular test. NCL5 must be distinguished from other neurodegenerations. OI is confirmed by radiography (multiple fractures) and molecular test.

1. Downs LM et al. 2011, SLC4A3 y GR-PRA1 en Golden retriever (PMID 21738669)
2. Downs LM et al. 2014, TTC8 y GR-PRA2 en Golden retriever (PMID 26401321)
3. Zangerl B et al. 2006, PRCD y prcd-PRA (PMID 16938425)
4. Grall A et al. 2012, PNPLA1 e ictiosis congénita del Golden retriever (PMID 22246504)
5. Gilliam D et al. 2015, CLN5 y NCL5 en Golden retriever (PMID 25934231)
6. OMIA:001374 GR-PRA1; OMIA:001376 GR-PRA2; OMIA:001314 prcd-PRA; OMIA:001482 NCL5