Cardiomyopathy and juvenile mortality / CJM (YARS2-related) - Belgian Shepherd

What does this test examine?

This genetic test analyses the YARS2 c.1054G>A variant in the Belgian Shepherd. The disorder is called cardiomyopathy and juvenile mortality or CJM.

What does this mean for the dog?

YARS2 encodes mitochondrial tyrosyl-tRNA synthetase 2, an enzyme required for mitochondrial protein synthesis and energy supply. Puppies with two copies of the variant can become severely ill after initially normal development at about 6 to 8 weeks of age. Reported signs include vomiting, shortness of breath, lethargy, tremors, muscle twitching, locomotion problems and rapid decline due to heart failure.

Practical value of this test

• The result distinguishes clear dogs, carriers and genetically affected dogs.
• Breeders can identify carriers and avoid pairings that may produce affected puppies.
• The test is especially relevant for Belgian Shepherd lines because affected puppies may die suddenly at a very young age.

The condition is inherited as an autosomal recessive trait. One copy means carrier status; two copies cause the CJM genotype with a severe risk of juvenile death.