ALL Sphynx breeders of the world should be aware of the high risk of HCM in their breeding cats and in the kittens they produce.  

In an attempt mitigate HCM in our breeding program and in the Sphynx breed itself, WE FEEL that all Sphynx cats that are part of a breeding program should be tested at age 1 and then ever year thereafter throughout their life; even after retirement.  Scanning for HCM will allow you to assess risk for individual cats and will help identify carriers of the genetic mutation, therefore allowing you mitigate disease from future lines.

Because HCM carriers are in the pedigrees of all Sphynx, it is very important to breed cautiously.  

How Do We Breed Cautiously?

Carefully study breed-wide pedigrees.  A high inbreeding co-efficient, with HCM prevalent in the lines can be very risky. 
Carefully study HCM data published in the Sphynx HCM Database in order to determine which lines are an are not producing HCM.
Test all breeding cats annually; even after retirement.  Submit all HCM data to the Sphynx HCM Database.
Although there may be other situations outside the scope of normal breeding circumstances, we use the following guidelines.  

Normal Heart:
Cats with a normal heart status according to a echo-cardiogram and without any close relatives* diagnosed with HCM can be used in breeding.
Diagnosed with HCM:
Cats diagnosed with HCM of any degree should not be used in breeding.
Equivocal:
Cats with inconclusive or borderline heart health status and with or without any close relatives* is not recommended to use for breeding until normal heart health is conclusively verified. Echo-cardiograms should subsequently be done every 6 months.  If the cat remains equivocal the cat should not be used in breeding. Also see *Considerations.

*Close Relatives:
Parents - If either parent has been diagnosed with HCM, the cat should not be used for breeding.
Siblings - If a full sibling has been diagnosed with HCM, and the heart is normal on the cat itself, it is not recommended to be used in a breeding program.
If the cat itself remains clear over the age of 5, and the *considerations lean towards allowing the cat to breed, discretion may be made if mated to a cat which is a risk free partner (not equivocal or cat with a close relative diagnosed with HCM). 
Other relatives - If other relatives have been diagnosed with HCM, and the heart is normal on the cat itself, it is not recommended to be used in a breeding program until the cat is scanning clear over the age of 2-3. If the cat itself remains clear over the age of 2-3, and the *considerations lean towards allowing the cat to breed, discretion may be made if mated to a cat which is a risk free partner (not equivocal or cat with a close relative diagnosed with HCM). 

*Considerations
In my experience, it "appears" that HCM affects males more often than females.
In my experience, it "appears" that "incomplete penetration" is more common in females.
Sphynx with hypertension, hyperthyroidism and hypersomatotropism can cause "non-genetic" HCM.  Therefore, appropriate tests should be performed.