Scientists Seeking Patient Input: Gene Therapy to Treat Inherited Cardiomyopathies

A group of scientists working on gene therapy for inherited cardiomyopathies are seeking input from patients about their interest and willingness to participate in gene therapy trials. These researchers hope that treatment with gene therapy will ultimately prove to be a cure for hypertrophic cardiomyopathy as well as other genetic cardiomyopathies.

If you are interested in learning more about gene therapy and are willing to answer a few questions about your willingness to participate in this type of research, watch this video.  Then, fill out this short questionnaire.  It just takes a few minutes and you may help to find a cure for HCM.

Targeted Gene Therapy for HCM

The expanding field of personalized medicine has not left hypertrophic cardiomyopathy behind. In fact, two companies are currently developing targeted gene therapies for HCM patients. Each therapy targets a separate and distinct HCM gene mutation.

Tenaya Therapeutics, located in the San Francisco area, is developing a therapy called TN-201 which is directed at mutations in the Myosin Binding Protein C3 (MYBPC3) gene. The therapy has shown favorable results in mice.  In May of this year, Tenaya received Orphan Drug Designation from the U.S Food and Drug Administration. An Orphan Drug Designation confers certain tax and economic incentives on companies developing a treatment for rare conditions.

Meanwhile, this week, Lexeo Therapeutics acquired Stelios Therapeutics, a San Diego based company developing a therapy for HCM patients with a mutation in the TNNI3 gene. These TNNI3 patients comprise somewhere between 5% and 7% of all patients with HCM, or approximately 30,000 people.  The underpinnings of this research come from the University of California, San Diego.

HCMBeat will continue following these developments. It is a busy and exciting time in the treatment of HCM!

Identical Twins Show Impact of Behavior and Environment on HCM

A recent study of identical twins with HCM found significant variation in the expression of hypertrophic cardiomyopathy, even between twins carrying the same HCM-causing genetic mutation. 

This paper concludes that epigenetics (things which influence expression of DNA like behavioral and environmental factors) greatly influence the expression of HCM genetic mutations. 

The researchers studied 11 pairs of twins with HCM. 9 of the twin pairs had known HCM sarcomere mutations while 2 of the pairs had HCM of unknown cause. The siblings were followed for a time frame of between 5 to 14 years.

Researchers compared left ventricular wall thickness, left atrial size and left ventricular ejection fraction. Differences were found in the left ventricular wall thickness of all 11 pairs of twins, while left atrial size was similar in 3 of the 9 twin pairs who carried HCM mutations. Left ventricular ejection fraction was different in 4 of 7 twin pairs. 

The researchers theorize that similarities in left atrial size may be due to impaired ventricular relaxation directly tied to sarcomere dysfunction. In contrast, environmental factors yield more influence over ventricular function.

HCM epigenetics is a field ripe for research. As HCM patients, we hope that it will yield actionable data in the near future.

HCM Genetics Discovery by British Researchers

A recent discovery by British researchers sheds light on how a type of common genetic mutation – a so called “common variant” – influences the expression of hypertrophic cardiomyopathy caused by mutation(s) in the cardiac sarcomere. 

How do Common Variants Impact Sarcomere Mutations?

This research, funded by the British Heart Foundation and spearheaded by Dr. Hugh Watkins of the University of Oxford, explains why some individuals with a particular sarcomere mutation develop a severe case of HCM, while their family members with the same mutation may develop only mild HCM symptoms or show no signs of the disease at all.  It also may explain why people who lack sarcomere mutations develop the disease.

The researchers compared the DNA of 2,780 people with HCM and 47,486 people without HCM and found that common variants acting in concert with rare sarcomere mutations determine whether a person will develop HCM. 

Common Variant HCM Not Hereditable

In addition, the researchers found that HCM attributable to common variants alone is unlikely to be passed on to future generations. This is good news for the children of HCM patients caused by common variants.

Watch your Blood Pressure

Lastly, this paper found that high diastolic blood pressure was associated with the development of  HCM caused by common variants. Hence, keeping blood pressure under control is something that patients can do to minimize their risk of developing HCM in the future.

A link to the study in Nature Genetics can be found here;
You can access a thorough summary by the British Heart Foundation here;
and you can find a short summary at Medical Xpress here.

2020 AHA/ACC HCM Diagnosis & Treatment Guidelines Released

The highly anticipated 2020 American Heart Association/American College of Cardiology Guidelines for the Diagnosis and Treatment of Patients with Hypertrophic Cardiomyopathy have been released.

This document, drafted with reference to published HCM literature, and with input from a committee of HCM experts with broad expertise, updates the prior version published in 2011.  It contains clinical practice guidelines for the broad spectrum of issues which may confront medical professionals as they approach the diagnosis and treatment of patients and families affected by hypertrophic cardiomyopathy.

Continue reading “2020 AHA/ACC HCM Diagnosis & Treatment Guidelines Released”

Wall Street Journal Highlights Risks in Genetic Testing

This story in the Wall Street Journal about genetic testing shows the speed of changes in the medical community’s understanding of how and whether certain genes cause hereditary disease.

The article quoted Dr. Jodie Ingles, a geneticist from the University of Sydney in Australia who specializes in HCM and has published a recent article on the subject.  Dr. Ingles said that 22 out of 33 genes comprising a genetic testing panel commonly used to test for HCM had either limited or no evidence of being disease causative.

Continue reading “Wall Street Journal Highlights Risks in Genetic Testing”

When Do You Screen Your Kids For HCM?

A recent study published in Circulation suggests that clinical testing of kids who are first degree family members of HCM patients (i.e. siblings and children of those who have already been diagnosed with HCM) could be improved by starting testing at a younger age. And, genetic testing should further improve diagnosis and treatment for this group.

Continue reading “When Do You Screen Your Kids For HCM?”

Are Your Genetic Test Results Valid?

A recent study by several HCM genetics researchers around the globe, led by Australia’s Dr. Jodie Inglesfound that 2/3 of genetic mutations previously reported to patients as HCM causative may actually NOT trigger HCM.

Continue reading “Are Your Genetic Test Results Valid?”

MyoKardia and 23andMe Create Online HCM Community

MyoKardia is collaborating with 23andMe, a genetic testing company which provides ancestry and health information directly to consumers, to create an online patient community intended to advance research efforts related to hypertrophic cardiomyopathy. The companies plan to allow 23andMe customers access to the latest information about HCM, as well as the opportunity to participate in research.

The companies will use a custom designed survey to collect baseline and follow-up data from HCM patients. They are hopeful that this collaboration will yield unique insights into HCM.

Research findings gained through the collaboration will be shared with HCM patients through the 23andMe platform.  Currently more than 6,000 HCM patients are customers of 23andMe

More details of the collaboration can be found:

Press release from MyoKardia and 23andMe

P&T Community

Genomeweb

 

 

 

 

DISCLOSURES:  HCMBeat has received unrestricted educational grants from MyoKardia.  Additionally, Cynthia Burstein Waldman of HCMBeat serves as a Patient Advisor on the Steering Committee for MyoKardia’s Explorer trial.

Is Whole Genome Sequencing a Better Method for HCM Genetic Testing?

According to this study published recently in the Journal of the American College of Cardiology, whole genome testing may sometimes be used to identify the gene(s) responsible for HCM when targeted genetic testing (the type used in the clinical setting) has been inconclusive.

In particular, the study found the responsible gene(s) in 9 of 26 families (20%) in whom targeted testing had previously been inconclusive.

When used as the initial form of genetic testing, whole genome sequencing identified the responsible HCM gene in 5 of 12 families, or 42%.

According to this article in Wired U.K., a whole genome sequencing test costs about $600 and takes just a few weeks to complete.  On the other had, the cost of data storage necessary to store such a large amount of collective data is, according to this article, prohibitively high.

If not for everyone, perhaps whole genome sequencing could be used in families where traditional genetic testing has proven inconclusive.  Time will tell.