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HIGH QUALITY DNA
TESTING YOU CAN TRUST
OUR PANELS
The tests in our DNA health testing panels are selected based on the scientific evidence available for disorders in the breed. Our scientists stay up to date with the latest developments and discoveries in the field to ensure that our testing panels are as up-to-date as possible.
DID YOU KNOW?
Our ISO-accredited testing services are relied upon by UK police forces for assessing the suitability of canine recruits for police duties.
TESTIMONIALS
approx. 2 weeks
Typical turnaround
2
Conditions screened
Simple cheek swab
At-home sampling
UK laboratory
Tested in-house
MacrothrombocytopaeniaMTCP
Macrothrombocytopaenia (MTCP) is a condition which causes a low blood platelet number but increased platelet size, with these two factors often resulting in an overall normal platelet function. It is important to inform your vet of this condition so they are not concerned by a low platelet count on blood tests.
An autosomal recessive condition caused by a mutation in the TUBB1 gene.
Note: this is the King Charles Cavalier Spaniel variant only.
How it's inherited
Recessive
What your result means
Clear (N/N): no copies; not expected to develop MTCP, nor pass it on.
Carrier (N/MTCP): one copy. Healthy, but can pass it on. Breeding two carriers risks affected puppies.
Affected (MTCP/MTCP): two copies; expected to develop MTCP. Discuss with your vet.
Progressive Retinal Atrophy -PRCDPRA-PRCD
Progressive Retinal Atrophy, progressive rod-cone degeneration type (PRA-PRCD), is an inherited eye condition in which the light-sensing cells of the retina gradually break down. It leads to night blindness first, then progressive loss of vision, often ending in blindness. Onset and speed vary. Testing supports breeding choices and early awareness.
Signs to look for
Early night blindness or reluctance in the dark, bumping into things in low light, dilated pupils or a reflective 'shine' to the eyes, progressing to daytime vision loss.
How it's inherited
Recessive — a dog needs two copies of the variant to be affected.
What your result means
Clear (N/N): no copies; not expected to develop PRA-PRCD, nor pass it on.
Carrier (N/PRA): one copy. Healthy, but can pass it on. Breeding two carriers risks affected puppies.
Affected (PRA/PRA): two copies; expected to develop PRA-PRCD. Discuss with your vet.
MacrothrombocytopaeniaMTCP
- Gene
- TUBB1
- Variant
- c.745 G>A
- Inheritance
- autosomal recessive
- OMIA
- OMIA002434 9615
Molecular mechanism
Thrombocytopenia, TUBB1-related is an inherited platelet disorder characterised by macrothrombocytopenia, in which affected dogs have reduced platelet numbers and enlarged platelets. The condition is inherited as an autosomal recessive trait and has been reported in Cavalier King Charles Spaniels, Norfolk Terriers and Cairn Terriers (Pedersen et al., 2002; Gelain et al., 2014).
In Cavalier King Charles Spaniels, Davis et al., (2008) identified a missense variant (c.745G\u0026gt;A; p.D249N) in the TUBB1 gene, encoding beta-1 tubulin, which correlated with the observed macrothrombocytopenia. A different TUBB1 missense variant was subsequently identified as the likely cause of a similar disorder in Norfolk and Cairn Terriers (Gelain et al., 2014).
The condition is generally asymptomatic, with the thrombocytopenia identified through blood analysis rather than clinical signs (Pedersen et al., 2002). Genetic testing can identify dogs carrying the known breed-associated variants, supporting informed breeding decisions. Note: only the King Charles Cavalier Spaniel TUBB1 variant is offered on this test, not the Norfolk/Cairn Terrier version.
References
Davis, B., Toivio-Kinnucan, M., Schuller, S., Boudreaux, MK. : Mutation in beta1-tubulin correlates with macrothrombocytopenia in Cavalier King Charles Spaniels. J Vet Intern Med 22:540-5, 2008. Pubmed reference: 18466252. DOI: 10.1111/j.1939-1676.2008.0085.x.
Gelain, M.E., Bertazzolo, W., Tutino, G., Pogliani, E., Cian, F., Boudreaux, M.K. : A novel point mutation in the β1-tubulin gene in asymptomatic macrothrombocytopenic Norfolk and Cairn Terriers. Vet Clin Pathol 43:317-21, 2014. Pubmed reference: 25060661. DOI: 10.1111/vcp.12168.
Pedersen, H.D., Haggstrom, J., Olsen, L.H., Christensen, K., Selin, A., Burmeister, M.L., Larsen, H. : Idiopathic asymptomatic thrombocytopenia in Cavalier King Charles Spaniels is an autosomal recessive trait J Vet Intern Med 16:169-73, 2002. Pubmed reference: 11899033. DOI: 10.1892/0891-6640(2002)016\u0026lt;0169:iatick\u0026gt;2.3.co;2.
Progressive Retinal Atrophy -PRCDPRA-PRCD
- Gene
- PRCD
- Variant
- c.5G>A (p.Cys2Tyr)
- Inheritance
- autosomal recessive
- OMIA
- OMIA 001298 9615
- Reported frequency
- A single PRCD variant is shared across a large number of breeds, making it one of the most commonly tested PRA forms.
Molecular mechanism
Progressive retinal atrophy (PRA) encompasses a genetically heterogeneous group of inherited retinal degenerative disorders characterised by the progressive loss of photoreceptor function, ultimately resulting in irreversible blindness. Although the clinical presentation is broadly similar across affected breeds, with initial degeneration of rod photoreceptors causing night blindness followed by cone degeneration and progressive loss of daylight vision, numerous genetically distinct forms of PRA have been identified (Miyadera et al., 2012; Mowat et al., 2024). Advances in canine molecular genetics have demonstrated that variants in multiple genes involved in photoreceptor development, maintenance and function can produce clinically similar retinal phenotypes. Consequently, breed-specific genetic testing is required, as different forms of PRA are associated with different causative variants.
PRA-PRCD is an autosomal recessive form of progressive retinal atrophy caused by a missense variant in the PRCD gene. PRCD Zangerl et al., (2006) identified a c.5G\u0026gt;A (p.Cys2Tyr) variant that has been reported across numerous dog breeds. Affected dogs are born with normal vision but gradually develop night blindness, progressing to complete blindness as both rod and cone photoreceptors degenerate. Widespread genetic testing has substantially reduced the frequency of this variant in several breeds, although carriers and affected dogs continue to be identified (Zangerl et al., 2006; Lewis \u0026amp; Mellersh, 2019; Clark et al., 2023).
The expanding number of recognised PRA-associated variants highlights the marked genetic heterogeneity underlying inherited retinal degeneration in dogs. While many of these variants are breed-specific, others are shared across multiple breeds through historical founder events. Genetic testing enables accurate identification of affected and carrier dogs, supporting informed breeding decisions aimed at reducing disease prevalence while preserving genetic diversity. As additional causative variants continue to be identified, molecular testing will remain an important tool for improving the diagnosis, management and long-term control of progressive retinal atrophy in canine populations (Lewis \u0026amp; Mellersh, 2019; Mowat et al., 2024).
References
References
Aguirre, G.D., Lohi, H., Kaukonen, M., Murgiano, L. : Formal commentary. PLoS Genet 16:e1009059, 2020. Pubmed reference: 33151924. DOI: 10.1371/journal.pgen.1009059.
Clark, J.A., Anderson, H., Donner, J., Pearce-Kelling, S., Ekenstedt, K.J. : Global frequency analyses of canine progressive rod-cone degeneration-progressive retinal atrophy and Collie eye anomaly using commercial genetic testing data. Genes (Basel) 14:2093, 2023. Pubmed reference: 38003037. DOI: 10.3390/genes14112093.
Downs, L.M., Wallin-Håkansson, B., Boursnell, M., Marklund, S., Hedhammar, Å., Truvé, K., Hübinette, L., Lindblad-Toh, K., Bergström, T., Mellersh, C.S. : A frameshift mutation in golden retriever dogs with progressive retinal atrophy endorses SLC4A3 as a candidate gene for human retinal degenerations. PLoS One 6:e21452, 2011. Pubmed reference: 21738669. DOI: 10.1371/journal.pone.0021452.
Downs, L.M., Bell, J.S., Freeman, J., Hartley, C., Hayward, L.J., Mellersh, C.S. : Late-onset progressive retinal atrophy in the Gordon and Irish Setter breeds is associated with a frameshift mutation in C2orf71. Anim Genet 44:169-77, 2013. Pubmed reference: 22686255. DOI: 10.1111/j.1365-2052.2012.02379.x.
Downs, L.M., Mellersh, C.S. : An intronic SINE insertion in FAM161A that causes exon-skipping is associated with progressive retinal atrophy in Tibetan Spaniels and Tibetan Terriers. PLoS One 9:e93990, 2014. Pubmed reference: 24705771. DOI: 10.1371/journal.pone.0093990.
Downs, L.M., Wallin-Håkansson, B., Bergström, T., Mellersh, C.S. : A novel mutation in TTC8 is associated with progressive retinal atrophy in the golden retriever. Canine Genet Epidemiol 1:4, 2014. Pubmed reference: 26401321. DOI: 10.1186/2052-6687-1-4.
Goldstein, O., Mezey, JG., Boyko, AR., Gao, C., Wang, W., Bustamante, CD., Anguish, LJ., Jordan, JA., Pearce-Kelling, SE., Aguirre, GD., Acland, GM. : An ADAM9 mutation in canine cone-rod dystrophy 3 establishes homology with human cone-rod dystrophy 9. Mol Vis 16:1549-69, 2010. Pubmed reference: 20806078.
Karlskov-Mortensen, P., Proschowsky, H.F., Gao, F., Fredholm, M. : Identification of the mutation causing progressive retinal atrophy in Old Danish Pointing Dog. Anim Genet 49:237-241, 2018. Pubmed reference: 29624701. DOI: 10.1111/age.12659.
Kaukonen, M., Quintero, I.B., Mukarram, A.K., Hytönen, M.K., Holopainen, S., Wickström, K., Kyöstilä, K., Arumilli, M., Jalomäki, S., Daub, C.O., Kere, J., Lohi, H. : A putative silencer variant in a spontaneous canine model of retinitis pigmentosa. PLoS Genet 16:e1008659, 2020. Pubmed reference: 32150541. DOI: 10.1371/journal.pgen.1008659.
Kropatsch, R., Petrasch-Parwez, E., Seelow, D., Schlichting, A., Gerding, WM., Akkad, DA., Epplen, JT., Dekomien, G. : Generalized progressive retinal atrophy in the Irish Glen of Imaal Terrier is associated with a deletion in the ADAM9 gene. Mol Cell Probes 24:357-63, 2010. Pubmed reference: 20691256. DOI: 10.1016/j.mcp.2010.07.007.
Lewis, T.W., Mellersh, C.S. : Changes in mutation frequency of eight Mendelian inherited disorders in eight pedigree dog populations following introduction of a commercial DNA test. PLoS One 14:e0209864, 2019. Pubmed reference: 30650096. DOI: 10.1371/journal.pone.0209864.
Mellersh, CS., Boursnell, ME., Pettitt, L., Ryder, EJ., Holmes, NG., Grafham, D., Forman, OP., Sampson, J., Barnett, KC., Blanton, S., Binns, MM., Vaudin, M. : Canine RPGRIP1 mutation establishes cone-rod dystrophy in miniature longhaired dachshunds as a homologue of human Leber congenital amaurosis. Genomics 88:293-301, 2006. Pubmed reference: 16806805. DOI: 10.1016/j.ygeno.2006.05.004.
Mowat, F.M., Iwabe, S., Aguirre, G.D., Petersen-Jones, S.M. : Consensus guidelines for nomenclature of companion animal inherited retinal disorders. Vet Ophthalmol 28:663-667, 2024. Pubmed reference: 38334230. DOI: 10.1111/vop.13185.
Miyadera, K., Acland, G.M., Aguirre, G.D. : Genetic and phenotypic variations of inherited retinal diseases in dogs: the power of within- and across-breed studies. Mamm Genome 23:40-61, 2012. Pubmed reference: 22065099. DOI: 10.1007/s00335-011-9361-3.
Murgiano, L., Becker, D., Torjman, D., Niggel, J.K., Milano, A., Cullen, C., Feng, R., Wang, F., Jagannathan, V., Pearce-Kelling, S., Katz, M.L., Leeb, T., Aguirre, G.D. : Complex structural PPT1 variant associated with non-syndromic canine retinal degeneration. G3 (Bethesda) 9:425-437, 2019. Pubmed reference: 30541930. DOI: 10.1534/g3.118.200859.
Petersen-Jones, S.M., Entz, D.D., Sargan, D.R. : CGMP phosphodiesterase-alpha mutation causes progressive retinal atrophy in the Cardigan Welsh corgi dog Investigative Ophthalmology \u0026amp; Visual Science 40:1637-1644, 1999. Pubmed reference: 10393029.
Suber, M.L., Pittler, S.J., Qin, N., Wright, G.C., Holcombe, V., Lee, R.H., Craft, C.M., Lolley, R.N., Baehr, W., Hurwitz, R.L. : Irish Setter Dogs Affected with Rod/Cone Dysplasia Contain a Nonsense Mutation in the Rod cGMP Phosphodiesterase beta- Subunit Gene Proceedings of the National Academy of Sciences of the United States of America 90:3968-3972, 1993. Pubmed reference: 8387203.
Svensson, M., Olsén, L., Winkler, P.A., Petersen-Jones, S.M., Bergström, T., Garncarz, Y., Narfström, K. : Progressive retinal atrophy in the Polski Owczarek Nizinny dog: a clinical and genetic study. Vet Ophthalmol 19:195-205, 2016. Pubmed reference: 26009980. DOI: 10.1111/vop.12284.
Wiik, A.C., Ropstad, E.O., Ekesten, B., Karlstam, L., Wade, C.M., Lingaas, F. : Progressive retinal atrophy in Shetland sheepdog is associated with a mutation in the CNGA1 gene. Anim Genet 46:515-21, 2015. Pubmed reference: 26202106. DOI: 10.1111/age.12323.
Winkler, P.A., Ekenstedt, K.J., Occelli, L.M., Frattaroli, A.V., Bartoe, J.T., Venta, P.J., Petersen-Jones, S.M. : A large animal model for CNGB1 autosomal recessive retinitis pigmentosa. PLoS One 8:e72229, 2013. Pubmed reference: 23977260. DOI: 10.1371/journal.pone.0072229.
Zangerl, B., Goldstein, O., Philp, AR., Lindauer, SJ., Pearce-Kelling, SE., Mullins, RF., Graphodatsky, AS., Ripoll, D., Felix, JS., Stone, EM., Acland, GM., Aguirre, GD. : Identical mutation in a novel retinal gene causes progressive rod-cone degeneration in dogs and retinitis pigmentosa in humans. Genomics 88:551-563, 2006. Pubmed reference: 16938425. DOI: 10.1016/j.ygeno.2006.07.007.
