Discovery of Gene Defect Linked to Heart Disease in
You can’t help but wonder if Dr.
Kathryn Meurs hollered “Bingo!” when she found a gene mutation in
Maine Coon cats that is clearly associated with feline hypertrophic
cardiomyopathy, the most common form of heart disease in cats. After years
of scratching for research dollars and laboriously sequencing genes, she
finally discovered the genes that were linked to sarcomeric proteins in
the heart and was recently able to publish the findings.
Dr. Mark Kittleson, a cardiac
veterinary specialist at the School of Veterinary Medicine at the
University of California, Davis has partnered with Meurs. “First we’ll
confirm this finding is really true of Maine Coon cats in the general
population (outside a lab setting), and then we look for other mutations
in other breeds. Meanwhile, we’re able to identify individual Main Coon
cats with the mutation. So, yes, this discovery is potentially important
for saving lives.”
Feline hypertrophic cardiomyopathy
(HCM) is by far the most common heart disease in cats. According to
several studies, it is also the number one cause of spontaneous death in
all indoor adult cats.
Just as the rare football star who
drops suddenly and dies on the field – the same thing occurs in
cats. Except, in cats, sudden death due to HCM is surprisingly common, and
often the first – and only - symptom. In people HCM is generally
diagnosed. In cats, when diagnosed, one symptom may be a clot, causing
debilitating stroke-like symptoms, which can be treated. The problem is
that these stroke-like events continue and typically worsen.
“This is very difficult to deal
with emotionally and also financially,” says Dr. Susan Little, executive
director of the Winn Feline Foundation, a not for profit organization that
helped to fund the ground-breaking research. “Sudden death though is
especially traumatic to witness – you’re just not prepared for it.”
Kittleson explains that HCM is a
thickening of the left chamber of the heart, causing the heart to
over-work. Sometimes vets can diagnose HCM hearing a murmur or an
exceedingly rapid heartbeat (though neither is always necessarily
indicative of HCM). Cardiac vets can identify HCM using an ultra-sound.
While any cat, including mixed
breeds, can have HCM, it was Kittleson who learned years ago, there is a
genetic and also a breed tendency, among the American Shorthair, Devon
Rex, Ragdoll, Persian and the Maine Coon.
Since HCM often isn’t found until cats are young adults or older, breeding out genetic carriers is challenging if not downright impossible. A male cat, for example, can sire several litters before he reaches, say 5 years, and then is unexpectedly diagnosed with HCM – even if there is no immediate family history. Kittleson says naturally that cat is neutered, but gene mutations – which ‘till now have remained a mystery - have already been potentially passed on.
Kittleson says the hopes now that
the mystery is unraveled – at least for Maine Coons – the hope is HCM
carriers can be identified as kittens.
Meurs, who was at Ohio State
University College of Veterinary Medicine – Columbus, has been sniffing
for the HCM gene abnormality since 1995. Several years of research focused
on sarcomeric proteins associated with the thickening of the heart that
occurs in HCM in people. The “Bingo” winner and breakthrough came when
Meurs discovered cardiac myosin binding protein C doesn’t get properly
incorporated into the muscle of the Maine Coon cats with HCM. Meurs then
traced the gene responsible for this abnormality.
Little, who is in Ottawa, Ontario,
Canada says, “By identifying the gene and the protein the gene produces,
it’s more likely a drug may be created to intervene.”
While there are drugs currently
used to hopefully control HCM (in the cats who are lucky enough to be
diagnosed), the reviews on their effectiveness are mixed at best.
Kittleson is now researching the
potential efficacy of two medications that would successfully treat HCM.
To determine the impact of these meds, Kittleson is looking at the hearts
of the cats using MRI imaging, a first for revealing changes in cats’
Generating Funds for Feline
The research conducted by Meurs
and Kittleson was financed through the Ricky Fund of the Winn Feline
Foundation, private donations to Ohio State and the University of
The Morris Animal Foundation is
another funder of animal health studies, and executive director Dr.
Patricia Olson says there’s actually a shortage of proposals on feline
“With so much to learn, and so
much to do it’s shocking and it’s inexcusable there’s money (for
funding research) that isn’t being used,” says veterinary cardiologist
Dr. Paul Pion, co-founder and president of the Davis, CA-based Veterinary
“I’m grateful for the dollars
I’ve received, but it’s a struggle,” says Kittleson. “I assume my
colleagues see a lot more money being thrown at the problem of HCM in
humans without a significant breakthrough – so they figure, how can we
ever solve the problem in cats?”
Pion, isn’t as diplomatic,
“With the progress Kate (Meurs) has made, it’s flabbergasting there
aren’t more investigators interested.”
Meurs, who is in the process of
setting up a new lab at Washington State University College of Veterinary
Medicine – Pullman, as the Dr. Richard L. Ott Endowed Chair in Small
Animal Medicine & Research points out there are many mutations in
human HCM, so it’s likely the mutations will vary as she investigates
other breeds. “The prospects are exciting, but we have a long ways to
go,” she says.
Kittleson – who with Pion –
helped to solve the mystery of a related heart disease in cats several
years ago says, “I just think about all the cats who suffer with this
disease or die early. My hope is that one day we can do something about
*Please note at this time there are varied opinions in dealing with the issue of HCM and the newly developed DNA test for one genetic cause of the disease. I havelisted information from a number of different sources expressing opinions on the subject. The content is solely the opinion of the author(s).
Recommendation by Drs. Mark Kittleson, Rebecca Gompf, and Susan Little
PawPeds Recommendation For Testing And Breeding
Recommendation by Dr. Jerold S Bell
Recommendation by Dr. Jens Haggstrom
HCM Screening Protocol: Breeder Guidelines - by Jody Chinitz, Paul Huntley, and others
Veterinary Cardiac Genetics Lab - A genetic test has been developed for the cMyBP-C mutation causing HCM in Maine Coons. Information about HCM and instructions to order the test kit.
Update from Kathyrn M. Meurs, DVM, PhD, Professor
Frequently Asked Questions about the test for the HCM Mutation
Q & A from Dr. Mark Kittleson
Feline Hypertrophic Cardiomyopathy - by Jody Chinitz, Marcia Munro, and Dr. Mark Kittleson
Feline Cardiomyopathies - by Dr. Paul Pion
CVCA's FAQ on cardiac diseases
- the feline section is halfway down the page
Hypertrophic Cardiomyopathy in Cats by PetPlace - by Dr. Bonagura
Summary page or In-depth article
Listing of Board Certified Veterinary Cardiologists with contact information, websites, and email
ACVIM Specialty of Cardiology - Alphabetic and Geographic lists of veterinary cardiology diplomates