Progressive Retinal Atrophy Lapponian Herder (PRA-LH)
Progressive Retinal Atrophy (IFT122-PRA), IFT122-PRA
Progressive Retinal Atrophy (PRA) is a category of disorders where the retinal cells in a dog’s eye degenerate and die eventually leading to complete blindness. A type of PRA specific to Lapponian Herders is due to a mutation in the IFT122 gene that leads to adult-onset eye disease. Symptoms will typically appear on average at 5 years old and is usually diagnosed anywhere from 5 to 12 years of age. Initial symptoms include vision difficulties in dim light often referred to as night blindness. As the disease progresses, the affected dog will continue to suffer loss of night vision which then progresses to visual deficits in brighter light and can eventually lead to total blindness. It is important to note that not all cases of PRA in Lapponian Herders are caused by this particular mutation.
Reading Your Results
These dogs have two copies of the normal gene and will neither develop Progressive Retinal Atrophy nor pass this mutation to their offspring.
B. (CARRIER/NOT AFFECTED):
These dogs have one copy of the normal gene and one copy of the mutation associated with this disease. They will not develop Progressive Retinal Atrophy but will, if bred, pass the mutation to 50% of its offspring, on average.
C. (AT RISK/AFFECTED):
These dogs have two copies of the mutation associated with Progressive Retinal Atrophy and will likely develop vision deficits and potential blindness.
Kaukonen M, Pettinen IT, Wickström K, Arumilli M, Donner J, Juhola IJ, Holopainen S, Turunen JA, Yoshihara M, Kere J, Lohi H. A missense variant in IFT122 associated with a canine model of retinitis pigmentosa. Hum Genet. 2021 Nov;140(11):1569-1579. [PubMed: 33606121]