Influence of Clinical Aspects and Genetic Factors on Feline HCM Severity and Development

Abstract

Hypertrophic cardiomyopathy (HCM), which is associated with thickening of the left ventricular wall, is one of the most common heart pathologies in cats. This disease has a hereditary etiology and is primarily related to mutations in the MYBPC3 and MYH7 genes. This study aims to determine the effect of the presence of heterozygosity or homozygosity for the p. A31P mutation (c.91G>C) in the MYBPC3 gene in cats (Maine Coon) of different ages referring to the HCM severity and development, and to compare echocardiographic data and various clinical aspects for the most objective detection of disease in cats of different breeds. The incidence of HCM was 59% of the 103 cases of heart disease in cats in this study. In 23 cats diagnosed with HCM, cats heterozygous for the mutation accounted for 34%, and homozygous cats accounted for 26%. Cats homozygous for this mutation had moderate to severe HCM, suggesting an association with high penetrance of HCM and a significant risk of cardiac death in this group. The penetrance of the heterozygous type was lower than that of the homozygous genotype. This study also indicates that HCM has some age-related penetrance. The disease did not occur in the study group of cats aged up to 1 year, whereas at the age of 7 and older, the percentage of animals diagnosed with HCM was the highest and amounted to 44.3% of the total number of studied cats with HCM.