UC Davis School of Veterinary Medicine Veterinary Genetics Laboratory

Primary Lens Luxation (PLL)


Primary Lens Luxation (PLL) is a painful inherited eye disorder where the lens of the eye moves from its normal position causing inflammation and glaucoma. PLL results from a single base change mutation in the gene ADAMST17. If untreated, the condition can rapidly lead to blindness. The disease is inherited in an autosomal recessive fashion thus both sexes are equally affected. PLL appears spontaneously, typically between 3-8 years, although both eyes are not necessarily affected at the same time. Watery, red, teary eyes may indicate that lens luxation has occurred and veterinary intervention is required. Dogs with only one copy of the disease mutation most frequently show no sign of the disease but can, on occasion, develop PLL. Breeding between two carriers is expected to produce 25% affected offspring.

The PLL mutation is widespread among Terrier breeds and genetic testing is recommended for this group of dogs. In addition, PLL is known to occur in;
American Eskimo Dog, Australian Cattle Dog, Chinese Crested, Chinese Foo Dog,
Danish-Swedish Farmdog, Italian Greyhound, Lancashire Heeler and
Volpino Italiano

The VGL offers a test for PLL to assist owners and breeders in identifying affected and carrier dogs. The test uses DNA collected from buccal (cheek) swabs, thus avoiding blood sample collection. Breeders can use results from the test as a tool for selection of mating pairs to avoid producing affected dogs.

Allow 3-6 business days for results.

Results reported as:

N/N no copies of the PLL mutation; dog is normal.
N/PLL 1 copy of the PLL mutation; dog is a carrier and at slight risk for developing PLL.
PLL/PLL 2 copies of the PLL mutation; dog is affected.


Farias FH, GS Johnson GS, JF Taylor, E Giuliano, ML Katz, DN Sanders, RD Schnabel, SD McKay, S Khan, P Gharahkhani, CA O'Leary, L Pettitt, OP Forman, M Boursnell, B McLaughlin, S Ahonen, H Lohi, E Hernandez-Merino, DJ Gould, D Sargan, CS Mellersh. (2010) An ADAMTS17 splice donor site mutation in dogs with primary lens luxation. Investigative Ophthalmology and Visual Science 51:4716-4721.

Gould D, L Pettitt, B McLaughlin, N Holmes, O Forman, A Thomas, S Ahonen, H Lohi, C O'Leary, D Sargan, C Mellersh. (2011) ADAMTS17 mutation associated with primary lens luxation is widespread among breeds. Vet Ophthalmol. 14(6):378-84.

Veterinary Genetics Laboratory, Tel 530-752-2211, Email VGL