GM2 gangliosidosis type I / B variant (HEXA-related) - Japanese Chin

What does this test analyse?

This genetic test analyses the HEXA c.967G>A variant in the Japanese Chin. The disorder is known as Gangliosidose GM2 type I / B-variant, Tay-Sachs-like GM2 type I, lysosomal storage disease, inherited neurodegenerative disorder and metabolic disease of the nervous system.

Gangliosidoses occur when the body cannot properly break down specific gangliosides. In this form, GM2-ganglioside accumulates in cells, with a strong impact on nerve cells. This causes a progressive neurological disorder with loss of coordination, tremors, abnormal movement, behavioural change, impaired growth and increasing deterioration. In Japanese Chin dogs, a severe progressive disorder is described with ataxia, behavioural change and vision problems.

Practical value of this test

The test is useful for breeders and owners who want to manage a serious recessive risk in their line before matings are planned. Carriers are usually healthy themselves, but can pass the variant on unnoticed. By testing breeding dogs, a carrier can be paired responsibly with a clear partner and carrier-to-carrier matings can be avoided, preventing affected puppies from this variant.

• Clear: the tested variant was not detected.
• Carrier: one copy of the variant is present and can be passed on.
• Affected genotype: two copies cause the tested gangliosidosis form.