Subvalvular aortic stenosis (SAS) is an inherited heart defect of several breeds of dogs. This is a defect located below the aortic valve that results in narrowed outflow and increased work on the heart. Currently, a mutation (PICALM) has been identified in association with SAS in Newfoundlands. 

Your veterinarian may be concerned that your Newfoundland has this trait if they detect a heart murmur when they evaluate your dog. The diagnosis can be confirmed with echocardiography by a veterinary cardiologist. Dogs with the severe form of the disease may die suddenly, often before 2 years of age. It is also possible for dogs to have a subtle form of the disease that can not be clinically detected, but they may still pass on the mutated gene if affected. 

The identified mutation is highly associated with SAS, but it is still a disease of incomplete penetrance. Presence of the mutation will not guarantee this heart defect or development of clinical signs, and disease can still occur in the absence of the mutation. 

Testing Prices:

Newfoundland SAS = $48.00 per dog

Newfoundland Litter Discount = $38.00 per puppy

Sample Type for Submission:

Acceptable samples include a cheek swab or 1-2 mL whole blood collected in an EDTA tube. If these sample types are unavailable, please reach out to us at cvm-cardiacgenetics@ncsu.edu for more information. Alternative sample types may result in an additional charge.

Explanation of Results:

Two copies of each gene are inherited, one from each parent. Possible results include:

Negative

Dogs have two copies of the normal gene, which is not predicted to be at an increased risk of SAS. They cannot transmit this mutation to their offspring.

Positive Heterozygous

Dogs have one copy of the normal gene and one copy of the mutated gene, which is associated with an increased risk of SAS. Dogs that are heterozygous often show signs of SAS by echocardiogram examination.

Positive Homozygous

Dogs have two copies of the mutated gene, which is associated with an increased risk of SAS. Dogs that are homozygous are likely to have evidence of SAS by echocardiogram examination. They will transmit one copy of the mutation to their offspring.

The identified mutation is highly associated with SAS, with an estimated 80% penetrance. This indicates that an estimated 80% of dogs with this mutation will have evidence of SAS.

Other factors could contribute to this condition in dogs, and a negative result does not rule out the presence of a different mutation that could cause a similar genetic disorder or trait.

Breeding Recommendations:

Breeding decisions should be made carefully and in discussion with your veterinarian. We cannot give specific breeding recommendations regarding your dog, but we advise to consider these genetic results as well as the overall health of the line. The goal is to reduce the prevalence of these disease-associated mutations while maintaining high quality variety within the population.