Prospective Echocardiographic and Tissue Doppler Imaging Screening of a Population of Maine Coon Cats Tested for the A31P Mutation in the Myosin-Binding Protein C Gene: A Specific Analysis of the Heterozygous Status

• Published in: Journal of veterinary internal medicine Vol. 23; no. 1; pp. 91 - 99
• Main Authors: Carlos Sampedrano, C, Chetboul, V, Mary, J, Tissier, R, Abitbol, M, Serres, F, Gouni, V, Thomas, A, Pouchelon, J.L
• Format: Journal Article
• Language: English
• Published: Malden, USA Blackwell Publishing Inc 2009; Wiley
• Subjects: Animal biology; Animals; Cardiomyopathy; Cardiomyopathy, Hypertrophic - genetics; Cardiomyopathy, Hypertrophic - veterinary; Carrier Proteins - genetics; Cat Diseases - genetics; Cats; Echocardiography; Echocardiography - veterinary; Feline; Female; Gene Expression Regulation; Genetic Predisposition to Disease; Genotype; Homozygote; Life Sciences; Loss of Heterozygosity; Male; Mutation; myosin; phenotype; Veterinary medicine and animal Health; feline; cardiomyopathy; echocardiography; genotype
• ISSN: 0891-6640; 1939-1676
• DOI: 10.1111/j.1939-1676.2008.0218.x

Background: A mutation in the sarcomeric gene coding for the myosin‐binding protein C gene has been identified in a colony of Maine Coon cats with hypertrophic cardiomyopathy (MyBPC3‐A31P mutation). However, the close correlation between genotype and phenotype (left ventricular hypertrophy [LVH] and dysfunction) has never been assessed in a large population, particularly in heterozygous (Hetero) cats. Objectives: To investigate LV morphology and function with echocardiography and tissue Doppler imaging (TDI) in a population of Maine Coon cats tested for the MyBPC3‐A31P mutation with focus on Hetero animals. Animals: Ninety‐six Maine Coon cats. Methods: Prospective observational study. Cats were screened for the MyBPC3‐A31P mutation and examined with both echocardiography and 2‐dimensional color TDI. Results: Fifty‐two out of 96 cats did not have the mutation (wild‐type genotype, Homo WT), 38/96 and 6/96 were Hetero‐ and homozygous‐mutated (Homo M) cats, respectively. Only 11% of Hetero cats (4/38) had LVH and 29% (10/34) of Hetero cats without LVH were >4 years old (4.1–11.5 years). LVH was also detected in 2 Homo WT cats (4%). A significantly decreased (P < .05) longitudinal E/A (ratio between early and late diastolic myocardial velocities) in the basal segment of the interventricular septum was observed in Hetero cats without LVH (n = 34) compared with Homo WT cats without LVH (n = 50), thus confirming that the Hetero status is associated with regional diastolic dysfunction (P < .05). Conclusions: The heterozygous status is not consistently associated with LVH and major myocardial dysfunction. Moreover, Homo WT cats can also develop LVH, suggesting that other genetic causes might be implicated.