Hypertrophic cardiomyopathy (HCM) in ragdoll cats has been associated with a substitution mutation in the myosin binding protein C3 (MYBPC3) gene. Prognosis is poor with HCM, and HCM is more likely to be severe in those homozygous for the mutation; however, the outcome for ragdoll cats tested for the MYBPC3 mutation has not been studied. Breeders and owners of MYBPC3 genotyped ragdolls completed a questionnaire to determine the influence of genotype on survival. Questions focused on signalment, genotype, current status (alive or dead), and date and circumstance of death (cardiac or noncardiac), if applicable.
Results found ragdoll cats homozygous for the C3 mutation were more likely to die from cardiac death and had a significantly shorter time before cardiac death. Mean survival time for homozygous cats was 5.65 years compared with >16.7 years and >15.2 years for heterozygous and wild-type (WT) cats, respectively. There was no significant difference in survival time between heterozygous or WT cats. Data suggest an incomplete dominance inheritance pattern. Study information may be helpful in counseling breeders and owners regarding genetic testing outcomes.