Type B PRA 2 [HIVEP3] (Miniature Schnauzer Type)



Test Overview:

Type A PRA is a difficult form of retinal atrophy as it can be partially dominant; some carrier animals appear partially affected when examined clinically. An abnormal shine may be apparent in the dog’s eyes as a result of increased pupil dilation, as the eye attempts to let in more light. The pupil will appear dark and glossy, and will not respond as quickly to light as an unaffected dog. Disorientation is also common symptom of PRA, particularly at night due to the degeneration of the light sensitive rods specializing in dim light perception. Initial night blindness in most cases will progress slowly to day blindness also as the cones in the eye that respond to bright light are progressively damaged. Sadly, like humans, there is no treatment or cure for blindness in dogs. The key findings of the study have several scientific and medical implications. We demonstrate the presence of at least two clinically and genetically different forms of PRA in the MS breed. The type 1 PRA with a homogeneous onset at 4 years of age mapped to chromosome 15, while the type 2 PRA, with an overrepresentation of affected males and a wider range of age of onset, mapped to chromosome X. While the tentative association in chromosome X needs to be replicated with additional cases, the association of the type 1 PRA in chromosome 15 was very strong.


Ophthalmologic - Associated with the eyes and associated structures


HIVEP3 chromosome 15

Variant Detected:

g.1432293 G>A


Low-Moderate. This disease can cause some discomfort and/or dysfunction in the affected animal. It does not generally affect life expectancy.

Mode of Inheritance:

Autosomal Recessive

Research Citation(s):

Kaukonen, 2020, PLoS Genet 16(3): e1008659

Associated Breed(s):

Miniature Schnauzer, Schnoodle,