Primary Lens Luxation

Primary Len Luxation is a well-recognised, painful and blinding eye condition that affects many breeds of dog. A mutation for this condition in several breeds was discovered by AHT scientists at the Kennel Club Genetics centre. This test has been available since 2009.

In dogs affected with Primary Lens Luxation (PLL) the zonular fibres that support the lens of the eye, breakdown or disintegrate. This causes the lens to fall in to the wrong position with in the eye. If the lens falls into the Anterior chamber of the eye Glaucoma and loss of vision an quickly occur.

Affected breeds

Jack Russell terrier, Parson Russell terrier,  Miniature bull terrier, Tibetan terrier, Lanchashire Heeler, Chinese Crested, Australian Cattle dog, Jagd terrier, Patterdale terrier, Rat terrier, Sealyham terrier, Tenterfield terrier, Toy Fox terrier, Volpino Italiano, Welsh terrier, Wire-Haired Fox terrier and Yorkshire terrier.

How is the disease inherited?

Parson Russell TerrierThe disorder shows an autosomal recessive mode of inheritance, which means that two copies of the defective gene (one inherited from each parent) have to be present for a dog to be affected by the disease.

Individuals with one copy of the defective gene and one copy of the normal gene, called carriers, show no signs of disease but can pass the defective gene onto their offspring.

When two carriers are crossed, 25% (on average) of the offspring will be affected by the disease, 25% will be clear and the remaining 50% will themselves be carriers.

When using our DNA test you will be sent results identifying your dog as belonging to one of three categories. In all cases the term “normal” and “mutation” refer to the position in the DNA where this PLL mutation is located. It is not possible to learn anything about any other region of DNA from this test.

Clear: This dog has two copies of the normal gene and will not develop PRIMARY LENS LUXATION as a result of the mutation we are testing for.

Carrier:This dog has one copy of the mutation and one normal copy of DNA. Our research has demonstrated that carriers have a very low risk of developing PRIMARY LENS LUXATION. The majority of carriers do not develop Primary Lens Luxation during their lives but a small percentage do.

Affected: This dog has 2 copies of the mutation and will almost certainly develop PRIMARY LENS LUXATION during their lifetime.

We cannot exclude the possibility that carriers might develop a similar condition due to other mutations they might carry that are not detected by this test.

Breeding advice

Carriers can still be bred to clear dogs. On average, 50% of such a litter will be clear and 50% carriers; there can be no affected dogs produced from such a mating.

Pups from such a litter should be DNA tested themselves to determine if they are Carrier or clear of this mutation. So informed choices can be made about future matings.

Clubs/associations receiving results:

The results of this DNA test as reported to the Kennel Club for the following breeds:  Chinese Crested, Jack Russell Terrier, Lancashire Heeler, Miniature Bull Terrier, Parson Russell Terrier, Sealyham Terrier, Tibetan Terrier and Welsh Terrier.

Results are only reported to clubs and associations within the country of residence given when ordering.

The following organisations also received results: Klub chovatelů naháčů ČR, Norwegian Kennel Club, Parson & Jack Russell Club of Austria, The Netherlands Vereniging JRT( Dutch JRT club), Tysk Jaktterrier Klubb of Sweden, Lancashire Heeler Club of Netherlands, The Finnish Lancashire Heeler Breed Club, The Swedish Lancashire Heeler Club, Bull Terrier Club Belgie, Swedish Bullterrier Club, Parson Russell Terrier Club of Ireland and Swedish Parson Russell Terrier Club.

Test Statistics

(updated 26/6/2017)

Total number tested: 14655

Affected: 388

Carrier: 4819

Normal: 9448

For more information please contact us and we’ll be happy to deal with your enquiry.

Invest Ophthalmol Vis Sci. 2010 Sep;51(9):4716-21. doi: 10.1167/iovs.09-5142. Epub 2010 Apr 7.An ADAMTS17 splice donor site mutation in dogs with primary lens luxation.Farias FH1, 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 DR, Mellersh C.

 Gould, D., Pettitt, L., McLaughlin, B., Holmes, N., Forman, O., Thomas, A., Ahonen, S., Lohi, H., O’Leary, C., Sargan, D. and Mellersh, C. (2011), ADAMTS17 mutation associated with primary lens luxation is widespread among breeds. Veterinary Ophthalmology, 14: 378–384. doi:10.1111/j.1463-5224.2011.00892.x