Preprint: Genotype-stratified study characterises hypertrophic cardiomyopathy in Maine Coon cats carrying MYBPC3-A31P

A preprint posted to bioRxiv on 19 August 2026 reports a genotype-stratified phenotypic characterisation of hypertrophic cardiomyopathy (HCM) in Maine Coon cats carrying the *MYBPC3* c.91G>C (p.A31P) variant. The study examines whether being heterozygous or homozygous for this variant affects the severity and nature of the cardiac phenotype.

HCM is the most common inherited cardiac condition in both humans and cats. In humans, pathogenic variants in *MYBPC3* — which encodes cardiac myosin binding protein C — account for approximately 40–50% of genetically solved HCM cases. The feline p.A31P variant is homologous in both genetics and pathology to human *MYBPC3* mutations. The authors note that mouse models of HCM are complicated by the thin interventricular septum of the mouse heart, which can make it difficult to distinguish pathological hypertrophy from normal anatomy; the larger body size of cats and their spontaneous development of HCM make them a potentially more tractable large-animal model.

The preprint is relevant to researchers in cardiac genetics, veterinary genetics, and those developing or evaluating animal models for inherited cardiac disease. Educators teaching variant dosage effects and genotype–phenotype relationships in dominant conditions may also find the dataset illustrative. Genetic counsellors advising families with *MYBPC3*-linked HCM may find the animal-model context of background interest.

This is a preprint and has not yet been peer-reviewed.