Mayo Clinic Minute: Mitral Valve Clip
Gene Linked to Mitral Valve Prolapse, a Common Heart Defect
Finding a gene related to mitral valve prolapse will enhance scientists' understanding of the causes of heart failure.
By Jennifer J. Brown, PhD
Don't Miss This
Sign Up for OurHeart HealthNewsletter
Thanks for signing up!You might also like these other newsletters:
THURSDAY, October 24, 2013 —Scientists have found a new human gene they think is the cause of mitral valve prolapse, a common heart valve defect — and one that can lead to heart failure. They presented their research today at the American Society of Human Genetics annual meeting in Boston.
“This is the first gene identified in patients with isolated mitral valve prolapse,” said Susan A. Slaugenhaupt, Ph.D., a professor at the Center for Human Genetic Research of Massachusetts General Hospital and Harvard Medical School in Boston.
Mitral valve prolapse is a heart valve defect that affects about one in every 40 people and can lead to heart conditions like arrhythmia (irregular heart beat), heart failure, and even sudden death.
The researchers worked with DNA of a multigenerational family to identify the gene. “It was a four-generation family, with 12 members affected with mitral valve prolapse,” Dr. Slaugenhaupt said.
All 28 of the family members for whom researchers had DNA samples and echocardiograms — a type of imaging of the heart — had the genetic analysis, according to Slaugenhaupt and co-investigator Ronen Y. Durst, MD, who presented the study at the conference in Boston. Dr. Durst is a cardiologist at Hebrew University and Hadassah Medical Center in Jerusalem.
Many genes are essential for processes as complex as the development of the human heart. Investigator Slaugenhaupt emphasized the complexity of a defective valve condition like mitral valve prolapse. “We know that there are multiple genes controlling normal mitral valve development," she said. The researchers named the new human gene they identified DCSH1, and located it on one of the 23 human chromosomes, number 11.
In a normal heart, the mitral valve is in control of blood flow between the chambers of the heart known as the atria and ventricles. For patients with the defect, the mitral valve does not close completely to create the usual seal between the heart chambers. Instead it bulges out and allows blood to flow in the wrong direction, leaking from the ventricle back into the atrium. This leakage is called “regurgitation.”
Symptoms of mitral valve prolapse include palpitations, shortness of breath, and chest pain.
Probing a New Human Gene’s Function With Animal Studies
In order to understand the effect of the newly found gene on human heart development, the researchers turned first to experimental animals: fish and mice. They tested the effect of having the gene, reducing the gene's function, or eliminating it entirely in these lab animals.
The researchers found that reducing the function of the DCSH1 gene in zebrafish disrupted the normal heart beat. In addition, “Treating the zebrafish embryos with the normal copy of the DCHS1 gene rescued the lesion,” stated Slaugenhaupt, which restored a normal heart. This is proof that this gene is essential for the heart to function properly.
In mice, knocking out the DCSH1 gene caused mitral valve pathology — lengthening and thickening of the heart valve — much like the gene does in people with the valve defect. Researchers found that this deformity resulted from developmental errors during formation of the mouse heart.
These results indicate that the human version of the DCSH1 gene is probably also involved in human heart development and formation of the mitral valve.
The Mitral Valve Prolapse Gene: What It Means for Patients
For people with mitral valve prolapse, abnormal backflow of blood can get worse over time. In the long term it can put the heart at increased risk of infections, and may require surgery to replace the mitral valve.
One of the ultimate goals of identifying a gene responsible for a human disease is to create screening tests for patients, to identify who has the condition. Another important goal is development of new drugs to treat the disease. In this case, it's too early in the research process to predict when this gene could be used for screening or drug development.
“We have to understand what the role of this gene is in the general population of patients with mitral valve prolapse. Studies are ongoing," Slaugenhaupt said.
Video: Mitral Valve Prolapse at Holy Cross Hospital: Vicente Font, MD, Cardiologist
See Fergie’s wedding pics
Game of Thrones Might End After Season 8
7 libri da leggere assolutamente a ottobre
60 The Creation Of Adam Tattoo Designs For Men – Michelangelo Painting Ideas
How to Take Care of Cows
Your partner is more likely to cheat on this day of the year
3 Ways to Access Email
Why Men Need to Say Sorry More
This Woman Invented A Bracelet That Might Make It Easier For You To Get Pregnant
15 local London restaurants that truly excel
Pregnancy diet: Is consuming ghee during pregnancy is safe in ninth month