Progressive retinal atrophy / PRA2 (CNGA1-related) - Shetland Sheepdog

What does this test analyse?

This genetic test analyses the c.1752_1755delAACT variant for progressive retinal atrophy / PRA2 in the Shetland Sheepdog. PRA is an umbrella term for inherited retinal disorders in which photoreceptors progressively deteriorate.

What does this condition mean?

CNGA1-PRA in the Shetland Sheepdog often starts with night blindness and loss of peripheral vision. Age of visible onset can vary widely, ranging from young adult dogs to older dogs in described cases.

CNGA1 encodes a channel protein required for photoreceptor signalling. The tested deletion causes a frameshift and premature stop codon. Because Shelties can also have other inherited eye disorders, variant-specific information is important.

Inheritance and result

The trait is inherited as an autosomal recessive condition. Clear dogs have two normal copies. Carriers have one copy of the variant and can pass it on. Dogs with two copies have the genotype that causes this PRA form.

Practical value of this test

• Helps breeders identify carriers before two carriers are combined.
• Enables targeted breeding plans without automatically losing healthy carriers from valuable lines.
• Gives buyers and owners clear information about genetic risk in a breed or line.
• Supports early preparation when a dog has a genetic risk for progressive vision loss.
• Helps distinguish this PRA variant from other inherited eye disorders within the same breed.

This test is especially valuable when a breed has several inherited eye problems: the result names the exact tested variant and makes breeding advice more concrete.