Background: Hypertrophic cardiomyopathy (HCM) is an inherited autosomal dominant trait in cats. The A31P single nucleotide polymorphism (SNP) in the myosin binding protein C 3 gene is thought to be the causative mutation in Maine Coon cats. Additionally, the A74T SNP is offered as a genetic test for HCM. Objectives: To evaluate the genetic association between the above-mentioned SNPs and phenotypes. Animals: Eighty-three Maine Coon cats and 68 cats of other breeds. Methods: The study was performed prospectively. Cats were phenotyped as healthy or HCM with echocardiography. Taqman genotyping assays were used for genotyping; results were confirmed by sequencing analysis. Results: A31P was found in 18/83 (22 per cent) Maine Coon cats. Fifteen of 18 Maine Coons (83 per cent) with the A31P mutation were healthy on echocardiographic examination (mean age 65 months). A74T was present in 28/79 (35 per cent) of Maine Coons and in 42/68 (62 per cent) of other cat breeds. Twenty-two of 28 (79 per cent) of Maine Coons and 21/42 (62 per cent) of other breed cats with the A74T mutation were healthy at a mean age of 72 months and 91 months, respectively. Of 12 Maine Coons with HCM, 9 (75 per cent) were genotype-negative for A31P and 6 (50 per cent) for A74T. Allele frequencies did not differ significantly (P= .47) between phenotype groups. None of the evaluated genetic tests was able to provide useful predictive information of disease outcome. Conclusions and Clinical Importance: The value of currently available genetic tests is low in the cats of this study. The mutations analysed appear to have a low penetrance, and even homozygote cats can remain healthy. The report is from the Ludwig-Maximilians-University, Munich, Germany.
Wess G, Schinner C, Weber K et al. J Vet Intern Med 2010 Apr 16 [Epub ahead of print].
Background: Hypertrophic cardiomyopathy (HCM) is an inherited autosomal dominant trait in cats. The A31P single nucleotide polymorphism (SNP) in the myosin binding protein C 3 gene is thought to be the causative mutation in Maine Coon cats. Additionally, the A74T SNP is offered as a genetic test for HCM. Objectives: To evaluate the genetic association between the above-mentioned SNPs and phenotypes. Animals: Eighty-three Maine Coon cats and 68 cats of other breeds. Methods: The study was performed prospectively. Cats were phenotyped as healthy or HCM with echocardiography. Taqman genotyping assays were used for genotyping; results were confirmed by sequencing analysis. Results: A31P was found in 18/83 (22 per cent) Maine Coon cats. Fifteen of 18 Maine Coons (83 per cent) with the A31P mutation were healthy on echocardiographic examination (mean age 65 months). A74T was present in 28/79 (35 per cent) of Maine Coons and in 42/68 (62 per cent) of other cat breeds. Twenty-two of 28 (79 per cent) of Maine Coons and 21/42 (62 per cent) of other breed cats with the A74T mutation were healthy at a mean age of 72 months and 91 months, respectively. Of 12 Maine Coons with HCM, 9 (75 per cent) were genotype-negative for A31P and 6 (50 per cent) for A74T. Allele frequencies did not differ significantly (P= .47) between phenotype groups. None of the evaluated genetic tests was able to provide useful predictive information of disease outcome. Conclusions and Clinical Importance: The value of currently available genetic tests is low in the cats of this study. The mutations analysed appear to have a low penetrance, and even homozygote cats can remain healthy. The report is from the Ludwig-Maximilians-University, Munich, Germany.
Wess G, Schinner C, Weber K et al. J Vet Intern Med 2010 Apr 16 [Epub ahead of print].