Primary lens luxation (PLL)

Pennuille tehtiin PLL testi - Puppies were tested for PLL - Valparna testades för PLL. Lue lisää täältä - Find out more here - Läs mera här: 
http://www.genoscoper.com/en/

Prima Neve Vero Verdi, Prima Neve Vinci Virgilio & Prima Neve Vannia Valentina: ovat PLL normaaleja - are PLL normal - är PLL fria

Prima Neve Veo Versace:  on kantaja - is a carrier - bär på anlaget

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Primary lens luxation (PLL) test for several breeds

Ocular lenses are held in place behind the pupil by zonular fibers which link the lens to the surrounding ciliary muscle. Rupture of the zonular fibers can result in the displacement of the lens producing a condition known as ectopia lentis. The disease is painful and the dog may become blind. The familial form of the ectopia lentis is known as primary lens luxation (PLL). PLL is present at high frequency in several terrier and terrier type breeds.
Researchers have now identified the first PLL mutation in several terrier breeds. A mutation-based test can identify normal, carrier and affected dogs. PLL is a recessive disease so usually only dogs that have two copies of the mutation will be affected. However, it has been noted that some percentage of the carrier dogs have similar symptoms indicating that there are other genetic or environmental factors that may play a role in the developement of the disease.
The following breeds are known to carry the mutation and can be tested:
Chinese Crested Dog
Jack Russell Terrier
Jagd Terrier
Lancashire Heeler
Miniature Bull Terrier
Parson Russell Terrier
Patterdale Terrier
Sealyham Terrier
Tibetan Terrier
Volpino Italiano
American Hairless Terrier
Rat terrier
Pumi
Australian Cattle Dog
Welsh Terrier
Yorkshire Terrier
Wire-haired Fox Terrier
Toy Fox Terrier
Studies have shown that the mutation occurs in high frequency in the affected breeds. Breeders are advised to use all dogs in breeding regardless of the genetic status. Otherwise the genetic diversity of the breed may become endangered. However, it is recommended to breed carrier dogs and genetically affected dogs with dogs that are DNA-tested normal/clear.
The test results are reported as follows:
NORMAL: The dog has two normal copies of gene. A dog that a has been tested normal will not develop PLL as a result of the mutation we are testing for. However, we cannot exclude the possibility of dogs tested normal developing PLL due to other causes including trauma or effects of other unidentified mutations.
CARRIER: The dog has one copy of the mutation and one normal copy of the normal gene. Carriers have a very low risk of developing PLL. The majority of carriers do not develop PLL during their lifetime. However, it is estimated that 2% – 20% of carriers will develop the condition. The reason for this is not yet known.
AFFECTED: The dog has two copies of the mutation and will almost certainly develop PLL during its lifetime. It is advised that all genetically affected dogs have their eyes examined by a veterinary ophthalmologist every 6 months, from the age of 18 months, so the clinical signs of PLL are detected as early as possible.
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References:
Sargan DR, Withers D, Pettitt L, Squire M, Gould DJ, Mellersh CS. Mapping the mutation causing lens luxation in several terrier breeds. J Hered. 2007; 98:534-538.
Farias FHG, Johnson GS, Taylor JF, Giuliano E, Katz ML, Sanders DN, Schnabel RD, McKay SD, Khan S, Gharahkhani P, O’Leary CA, Pettitt L, Forman O, Boursnell M, McLaughlin B, Ahonen S, Lohi H, Hernandez-Merino E, Gould DJ, Sargan DR, and Mellersh C. A Splice Donor Mutation in Dogs with Primary Lens Luxation, Invest Ophthal and Vis Science, in press, 2010.

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