Testing of dogs: CSNB in Beagles
Related tests
- Combination Beagle CAT + CSNB + FVII + IGS + MLS + NCCD + OI + PK + POAG
Congenital Stationary Night Blindness (CSBN) in Beagles
Congenital stationary night blindness is an inherited eye disease that is characterized by slow progressive retinal degeneration. It is caused by dysfunctions in ON-bipolar cells which are secondary neurons of the retina. The disease initially manifests itself as night blindness, but gradually progresses and can lead to complete blindness.
In beagles, the disease is caused by a 1bp deletion in the LRIT3 gene. The mutation leads to a truncated protein with defective function.
The genetic test can clearly reveal the genotype of the animal and is a useful tool for breeders to prevent unintentional breeding of affected puppies.
The disease affects dogs with P/P (positive / positive) genotype only. Dogs with P/N (positive /negative) genotype are clinically without any symptoms. They are genetically considered carriers of the disease (heterozygotes). In offspring of two heterozygous animals following genotype distribution can be expected: 25 % N/N (healthy non-carriers), 25 % P/P (affected), and 50 % N/P (healthy carriers). Because of high risk of producing affected offspring, mating of two N/P animals (carriers) can not be recommended.
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Reference:
Das, R.G., Becker, D., Jagannathan, V., Goldstein, O., Santana, E., Carlin, K., Sudharsan, R., Leeb, T., Nishizawa, Y., Kondo, M., Aguirre, G.D., Miyadera, K. : Genome-wide association study and whole-genome sequencing identify a deletion in LRIT3 associated with canine congenital stationary night blindness. Sci Rep 9:14166, 2019. Pubmed reference: 31578364