Hypertrophic cardiomyopathy in the Sphynx cat: A retrospective evaluation of clinical presentation and heritable etiology

Abstract

Hypertrophic cardiomyopathy is an inherited disease in some feline breeds including the Maine Coon and Ragdoll. In these breeds, distinct causative genetic mutations have been identified. The two breeds appear to have slightly different clinical presentations, including age of diagnosis. The observation that these two breeds may have different clinical presentations, as well as different genetic mutations, suggests that hypertrophic cardiomyopathy is a diverse disease in the cat. Hypertrophic cardiomyopathy is poorly described in the Sphynx. The objective of this study was to phenotypically characterize Sphynx hypertrophic cardiomyopathy and to evaluate for a familial etiology. Records of 18 affected cats (11 female, seven male) were evaluated. Age of affected cats ranged from 0.5 to 7 years (median, 2 years). Four affected cats were from a single family and included an affected cat in each of four generations (three females, one male). Further studies are warranted to evaluate for a causative mutation and better classify the phenotypic expression.

International collaborative study to assess cardiovascular risk and evaluate long‐term health in cats with preclinical hypertrophic cardiomyopathy and apparently healthy cats: The REVEAL Study

“…2,5,[7][8][9][15][16][17][18][19][20]25,26,28 Certain breeds including Maine Coon, Ragdoll, British shorthair, Sphynx, Chartreux, Persian, Domestic Shorthair, and Norwegian Forest Cats are predisposed to hypertrophic cardiomyopathy, suggesting a heritable basis in these populations. [10][11][12]24,[29][30][31][32][33][34][35][36][37][38] Despite the fact that this disease is widely recognized, risk of attendant cardiovascular complications is unknown, and the natural history of preclinical feline hypertrophic cardiomyopathy remains unresolved.…”

The genetic basis of hypertrophic cardiomyopathy in cats and humans

“…106,107 After the first two mutations in MYBPC3 were identified, other feline breeds were screened for mutations in sarcomeric genes. In one study, 14 cats with HCM representing 5 different breeds (Sphynx, Norwegian Forest Cat, Siberian, British Shorthair, and Maine Coon [without the A31P mutation]) were examined for mutations in genes encoding cardiac troponin I, troponin T, MYBPC3, essential and regulatory light chains, alpha-tropomyosin, actin, and MYH7.…”

Myosin‐Binding Protein C DNA Variants in Domestic Cats (A31P, A74T, R820W) and their Association with Hypertrophic Cardiomyopathy

“…In cats, a breed prevalence, suggesting a heritable component for HCM, is described in Siberian, Sphynx, American Shorthair, Cornish Rex, Persian, European, British Shorthair, Bengal, Chartreux, and Norwegian Forest cats. [7][8][9][10][11][12][13][14][15] Autosomal dominant inheritance and 2 causal mutations resulting in amino acid substitution -A31P and R820Win Cardiac Myosin-Binding Protein C3 (MYBPC3) have been identified in Maine Coons and Ragdolls with HCM, respectively. 9,13 In humans, l-thyroxine mutations in MYBPC3 typically exhibit low and agerelated penetrance in heterozygotes.…”