Primary Open Angle Glaucoma
Affected Genes: ADAMTS10
Inheritance: Autosomal Recessive
Variant(canFam6):
chr20:52896776: C>T
Breed: Beagle
Carlin Pinscher
General Information: Primary Open Angle Glaucoma (POAG) is a genetic eye disorder that affects Beagles, typically presenting between 8 to 16 months of age. The condition leads to increased pressure within the eyes, causing the eyeballs to enlarge and become painful. Early signs include excessive blinking, tearing, and redness. Without treatment, this increased pressure damages the optic nerve, leading to gradual vision loss. By around 2.5 years of age, many affected dogs exhibit lens luxation, where the lens dislocates within the eye. Symptoms of lens luxation include squinting, tearing, and excessive blinking. Forward dislocation is more common and can exacerbate glaucoma and vision loss if not treated promptly. Other symptoms may include bulging eyes and cataracts.
How to Read Your Dog's Test Results for this Genetic Variant:
Two Variants Detected: Dog Likely Affected
One Variant Detected: Dog Unlikely Affected
No Variants Detected: No Effect
Gene / Testing Information: Genetic testing for POAG in Beagles focuses on the ADAMTS10 gene. This condition is inherited in an autosomal recessive manner, meaning that a dog must inherit two copies of the mutated gene (one from each parent) to be affected. Carrier dogs, which have one normal and one mutated gene, do not show symptoms but can pass the mutation to their offspring. If two carriers are bred, there is a 25% chance of producing an affected puppy and a 50% chance of producing a carrier. Genetic testing is essential for responsible breeding practices to avoid producing affected pups. By breeding carriers only with dogs that do not carry the mutation, breeders can help eliminate this condition from their lines. Since symptoms may not appear until adulthood, it's crucial to perform genetic testing before breeding to ensure healthy offspring.
References:
Gelatt KN, Peiffer RL Jr, Gwin RM, Gum GG, Williams LW. Clinical manifestations of inherited glaucoma in the beagle. Invest Ophthalmol Vis Sci. 1977 16(12):1135-1142.
Kuchtey J, Kunkel J, Esson D, Sapienza JS, Ward DA, Plummer CE, Gelatt KN, Kuchtey RW. Screening ADAMTS10 in Dog Populations Supports Gly661Arg as the Glaucoma-Causing Variant in Beagles. Invest Ophthalmol Vis Sci. 2013 54(3):1881-1886.
Kuchtey J, Olson LM, Rinkoski T, MacKay EO, Iverson TM, Gelatt KN, Haines JL, Kuchtey RW. Mapping of the disease locus and identification of ADAMTS10 as a candidate gene in a canine model of primary open angle glaucoma. PLoS Genet. 2011 7(2):e1001306.