HCM and Maine Coon Cats: Genetics, Screening, and What to Ask

What buyers should understand

HCM is not a single story with one villain gene and one easy fix. In Maine Coons, researchers identified a DNA change in the MYBPC3 gene (often called A31P) that shows up frequently in screened populations. Peer-reviewed surveys report the mutation in a large minority of cats tested, with percentages that swing by region and sampling (roughly one-third to well over forty percent in some published cohorts).

Important nuance from those same studies: many cats with the mutation never develop obvious disease, while some cats without the mutation still develop HCM. That is why responsible programs lean on ultrasound screening by a boarded cardiologist, not a cheek swab alone.

Echocardiogram vs. DNA

• Echocardiogram looks at the actual thickness and motion of the heart today.
• DNA tells you whether one risk allele is present; it is useful for pairing decisions and transparency, but it is not a lifetime guarantee either way.

Think of them as complementary tools, not substitutes.

TICA’s Maine Coon breed page summarizes what responsible breeders aim for: periodic echocardiograms read by a board-certified veterinary cardiologist plus genetic testing, because not every mutation is known and a normal DNA result is not a lifetime pass.

Questions worth asking any breeder

• When did each parent last see a cardiologist, and can you show the report summary?
• Do you track pedigrees for early sudden deaths even when parents tested “normal” as young cats?
• What happens if my kitten’s vet hears a murmur at the first visit?

After the kitten comes home

Plan on annual veterinary exams and a conversation with your own vet about whether repeat cardiac screening makes sense as your cat ages. Insurance policies differ wildly on hereditary conditions, so read the fine print if you buy coverage.