Cardiac arrhythmia

General Information: Cardiac Arrhythmia (QIL1) is an inherited disorder in dogs that affects the normal electrical activity of the heart, leading to irregular heartbeats. Dogs with two copies of the associated QIL1 gene mutation are predisposed to this condition, which can manifest at any age. Symptoms of cardiac arrhythmia may include exercise intolerance, weakness, fainting (syncope), lethargy, and in severe cases, sudden collapse or death. The irregular heartbeats can disrupt the heart's ability to pump blood efficiently, potentially leading to heart failure over time. Not all dogs with the mutation will show symptoms initially, but the condition may worsen with age or stress. Early diagnosis and careful management are essential for maintaining the affected dog’s quality of life.

How to Read Your Dog's Test Results for this Genetic Variant:

Two Variants Detected: Dog Likely Affected

One Variant Detected: Dog Unlikely Affected

No Variants Detected: No Effect

Gene / Testing Information: Genetic testing for the QIL1 gene variant can determine whether a dog is at risk of developing cardiac arrhythmia. This disorder is inherited in an Autosomal Recessive manner, meaning dogs must inherit two copies of the mutated gene—one from each parent—to develop the disease. Carrier dogs, with only one copy of the mutation, typically do not show symptoms but can pass the gene to their offspring. When two carriers are bred, each puppy has a 25% chance of being affected and a 50% chance of being a carrier. Reliable genetic testing is crucial for informed breeding practices, as breeding two carriers together increases the risk of producing affected puppies. Dogs that are not carriers have no increased risk of having affected offspring.