Hypertrophic Cardiomyopathy (Domestic cat type)

 

Gene: MYH7

Transmission: Autosomal, probably dominant

The animal only has to have one copy of the mutation to be at risk of developing hypertrophic cardiomyopathy.  Animals with two copies of the mutation generally have more severe symptoms and an earlier onset of the disease than animals with just one copy of the mutation.  Offspring are potentially at risk of developing the disease if at least one parent carries the mutation.

Mutation: Substitution, MYH7 gene: c.5647 G>A, p. (Glu1883Lys)

Medical system: Cardiac

Breeds: Domestic Cat

Age of onset of symptoms: 5 to 7 years of age on average

Hypertrophic cardiomyopathy is a genetic disease characterized by hypertrophy (thickening) of the heart muscle in the left ventricle.  In general, cats with hypertrophic cardiomyopathy may be asymptomatic or symptomatic. Clinical signs include a heart murmur, galloping sound or arrhythmia on auscultation. In cats more advanced in the disease, signs of congestive heart failure, aortic thromboembolism, syncope and even sudden death can be found. Diagnosis can be confirmed with an echocardiogram or on necropsy.

A domestic shorthair cat was diagnosed at necropsy with hypertrophic cardiomyopathy.   A heterozygous mutation in the MYH7 gene was detected and considered pathogenic following sequence comparisons with other species.  A survey of 200 additional cats found no other evidence for the mutation.  For the time being, this mutation in the MYH7 gene in cats, while of academic interest, does not appear to be of major clinical relevance.

Note that hypertrophic cardiomyopathy in the cat has complex genetics with a number of known gene mutations involved as well as unknown mutations yet to be identified.  Characterized mutations include:

Mutations gene MYBPC3, Maine Coon and Ragdoll.  OMIA link: [0515-9685]

Mutation gene ALMS1, Sphynx.  OMIA link: [2316-9685]

Mutation gene MYH7, domestic cat.  Lien OMIA : [2122-9685]

 

References:

OMIA link: [2212-9685]

Boeykens F, Abitbol M, Anderson H, et al. (2024) Classification of feline hypertrophic cardiomyopathy-associated gene variants according to the American College of Medical Genetics and Genomics guidelines. Front Vet Sci 11:1327081.  [pm/38371598]

Kittleson MD, Côté E. (2021) The feline cardiomyopathies: 2. Hypertrophic cardiomyopathy. J Feline Med Surg 23:1028-1051. [pubmed/34693811]

Kittleson MD, Côté E. (2021) The feline cardiomyopathies: 1. General concepts.  J Feline Med Surg 23:1009-1027.  [pm/34693806]

O’Donnell K, Adin D, Atkins CE, et al. (2021) Absence of known feline MYH7 and MYBPC3 variants in a diverse cohort of cats with hypertrophic cardiomyopathy. Anim Genet 52:542-4.  [pm/33970514]

Gil-Ortuño C, Sebastián-Marcos P, Sabater-Molina M, et al. (2020) Genetics of feline hypertrophic cardiomyopathy. Clinical Genetics. 98: 203–214. [pm/32215921]

Schipper T, Van Poucke M, Sonck L, et al. (2019) A feline orthologue of the human MYH7 c.5647G>A (p.(Glu1883Lys)) variant causes hypertrophic cardiomyopathy in a Domestic Shorthair cat. Eur J Hum Genet 27:1724–1730. [pm/31164718]

 

Contributed by: Casandra Gilbert and Sarah-Maude Paquet, Class of 2028, Faculty of Veterinary Medicine, University of Montreal. (Translation DWS).