Hypertrophic cardiomyopathy (HCM)
A thickening of the heart muscle that can cause sudden cardiac death; Cornell's Feline Health Center lists Persian among the breeds in which HCM is more prevalent than in the general cat population. No specific causal DNA mutation has been established for Persian-type HCM, unlike the discrete mutations known in Maine Coon and Ragdoll, so a clear DNA test cannot rule it out.
What to ask for
Cardiologist echocardiogram of both parents (no validated breed-specific DNA marker exists)

