Breeds Affected: Many Terriers (Parson Russell, Jack Russell, Patterdale, Rat, Sealyham, Tenterfield, Toy Fox, Tibetan, Welsh, Wirehaired Fox, Yorkshire, Miniature Bull, Lakeland, Lucas, Norwich), Lancashire Heeler, Australian Cattle Dog, Chinese Crested Dog, Danish-Swedish Farmdog, Jagdhund, Shih Tzu, Spanish Waterdog, Standard Poodle, Volpino Italiano, and American Eskimo Dog.
Samples Accepted: Blood, Buccal Swabs
Disease Information: Primary Lens Luxation (PLL) is an eye disease in which fibers in the eye which hold the lens in place lose structural integrity and the lens is able to move out of place (luxate). This in turn causes painful glaucoma, and is usually bilateral, resulting in blindness. Symptoms are usually noted between 3 – 8 years of age.
Inheritance Information: Primary Lens Luxation is considered to be autosomal recessive, meaning that animals with two copies of this allele will be affected, and animals with one copy of the gene will be clinically-normal carriers; however, several affected dogs have been found to be heterozygous.
The possible genotypes are:
N/N The dog is normal, and cannot produce affected offspring.
N/pll The dog is a carrier, and can pass the allele on to approximately 50% of any offspring. If bred to another N/pll carrier, approximately 25% of the offspring will be normal, 50% will be carriers, and 25% will be affected.
pll/pll The dog is affected, and if bred to a normal animal, 100% of the offspring will be carriers. If bred to an N/pll carrier, 50% of the offspring will be carriers and 50% will be affected.
– Carriers may be bred to normal animals (N/pll x N/N) without any risk of producing affected offspring. The offspring should be tested before breeding to determine if they are carriers or normal.
– Breeding two carriers (N/pll x N/pll) is not recommended due to the possibility of 25% of the offspring being affected.
– Affected animals (pll/pll) should not be used for breeding.
Test Information: This test identifies a single base change in the ADAMTS17 gene.
Donner, J., Kaukonen, M., Anderson, H., Möller, F., Kyöstilä, K., Sankari, S., Hytönen, M., Giger, U., Lohi, H. :Genetic Panel Screening of Nearly 100 Mutations Reveals New Insights into the Breed Distribution of Risk Variants for Canine Hereditary Disorders. PLoS One 11:e0161005, 2016. Pubmed reference: 27525650. DOI: 10.1371/journal.pone.0161005.
Farias, FH., Johnson, GS., Taylor, JF., Giuliano, E., Katz, ML., Sanders, DN., Schnabel, RD., McKay, SD., Khan, S., Gharahkhani, P., O’Leary, CA., Pettitt, L., Forman, OP., Boursnell, M., Mclaughlin, B., Ahonen, S., Lohi, H., Hernandez-Merino, E., Gould, DJ., Sargan, D., Mellersh, CS.: An ADAMTS17 Splice Donor Site Mutation in Dogs with Primary Lens Luxation. Invest Ophthalmol Vis Sci :, 2010. Pubmed reference: 20375329. DOI: 10.1167/iovs.09-5142
Further information is available at the Online Mendelian Inheritance in Animals website.