Hypertrophic cardiomyopathy (HCM) is the inward thickening of the heart muscle which reduces chamber volume. The reduction of chamber volume reduces the volume of blood that can be pumped through the heart with each contraction. This causes health issues and eventually, death. There is no cure for HCM. Many purebred cats have higher incidents of HCM including Sphynx. This is why our breeding cat's hearts are screened once a year using an echocardiogram completed by a board certified cardiologist.
Unfortunately, even with the yearly screenings, HCM can still affect any cat at any age at any time. Always purchase your kitten from a reputable breeder with annual HCM scanning in place for every breeding cat. Please, have your sphynx cat's heart screened for HCM by a board certified cardiologist once a year after your kitten turns one year of age. OUR HCM GUARANTEE WILL BE VOID IF THIS REQUIREMENT IS NOT MET.
While HCM is not curable, science has come a long way in treating the symptoms of HCM which could allow your cat to live a longer, better quality of life, even if he/she is diagnosed with this disease. For more information about this illness, please visit: http://www.hairlesshearts.org/
NC State has very recently identified a DNA mutation in about 60% of affected Sphynx Cats. This mutation is also found occasionally in healthy adult Sphynx cats who do not have the disease. This referred to as “incomplete penetrance”. This means that even if a cat has the genetic mutation, the mutation may not actually penetrate or lead to the development in full disease in that cat. This is also a common finding in Maine Coons, Ragdolls and human beings with genetic mutations associated with Hypertrophic cardiomyopathy. Importantly since this mutation only appears to have identified about 60% of affected cats, it appears likely that there is at least one other Sphynx cat HCM Mutation DNA test results will indicate if the cat has the mutation on 1 copy of its 2 gene copies (called heterozygous) or both gene copies (homozygous). At this time, we do not know if the risk of developing disease is higher in cats that are homozygous for the mutation than heterozygous. The current interpretations of the possible test results are: Negative ( -/- ) Negative cats have two copies of the normal, unmutated gene. Very importantly, the absence of the mutation in this cat does not mean that it will never develop the disease. It means that it does not have the only known mutation that can cause the disease in the cat at this time. In the future, additional mutations may be identified that may be tested for as well. Positive Heterozygous: (+/-) Cats who are Positive Heterozygous for the HCM mutation have 1 copy of the mutated gene and 1 copy of a normal gene. Cats that are positive for the test will not necessarily develop significant heart disease and die from the disease. Some cats will develop a very mild form of the disease and will live quite comfortably. We recommend annual evaluation by an echocardiogram and discussion with a veterinarian for treatment options if hypertrophy develops. Positive Homozygous: (+/+) Cats who are Positive Homozygous for the HCM mutation have 2 copies of the mutated gene and may have a greater likelihood of showing severe signs of hypertrophic cardiomyopathy. Importantly, breeding decisions should be made carefully. At this time, we do not know what percent of the overall Sphynx cat population carry at least one copy of the gene. Removal of a large number of cats from the breeding population could have a negative impact on the breed. Remember that HCM affected cats also carry other important good genes that we do not want to lose from the breed. In general, we recommend not breeding homozygous cats and, if needed, breeding heterozygotes to unaffected cats to decrease the risk of producing affected cats.
As we move forward with our breeding program, we are working towards selecting Kings and Queens who are negative for this gene. Keep in mind that we are continually learning about this disease and recommendations will be altered as we obtain more information.
