Description: Cardiomyopathy with juvenile mortality (CJM) is an inherited disease characterized by the early death of puppies, often at birth or at the age of max. 6-8 weeks. The development of puppies is initially normal, later non-specific clinical symptoms appear, such as vomiting, imbalance, insufficient coordination of movements (trembling, burying), respiratory problems. Puppies die a few days after the onset of the first clinical signs due to heart failure.
The disease is caused by mutation c. 1054G>A in the YARS2 gene, which encodes mitochondrial tyrosyl-tRNA synthetase 2. Eukaryotic organisms have two tyrosyl-tRNA synthetases – cytoplasmic (YARS1) and mitochondrial (YARS2). These two types of synthetase have evolutionarily conserved sequence motifs (observed in animals, fungi, but also plants), indicating the importance of maintaining the correct sequence for function in the body. The mutation causes the evolutionarily conserved negatively charged glutamate in the tRNA binding domain to be replaced by positively charged lysine. Thus, the c.1054G>A mutation affects the function of the YARS2 gene, preventing proper recognition and binding to mitochondrial tRNA. Loss of YARS2 function can also be observed in humans, patients have similar symptoms to Belgian Shepherds, suffer from myopathy, lactic acidosis, anemia, and lead to an early death.
Inheritance: autosomal recessive
Mutation: c. 1054G>A in YARS2 gene
Sample: EDTA whole blood (1.0 ml) or 2 buccal brushes
The analysis is suitable for the following breeds: Belgian Shepherds Malinois