New mechanism discovered to treat genetic heart disorders

Washington: Heart is known as the pump to the body, which works in co-ordination with valves divided in between the left and the right ventricle. Researchers have discovered a new mechanism involved in a common congenital disease of the aortic valve located in the left ventricle.

Valve disease affects two per cent of the population, which is a significant proportion. Despite this high incidence and many signs that point to the role played by genetics in aortic diseases, only a few genes have been identified to date.

According to Dr Gregor Andelfinger, a pediatric cardiologist and researcher at CHU (Centre Hospitalier Universitaire) Sainte-Justine and at Universite de Montreal, the valve diseases can affect one of the heart's four valves -- the tricuspid, pulmonary, mitral or aortic valve.

"We looked at patients with a bicuspid aortic valve, which is an aortic valve that has only two functional leaflets instead of the usual three. Most patients affected by this valve disease are asymptomatic in early life. But in adulthood, this bicuspid valve can leak or cause premature aortic narrowing, resulting in shortness of breath or abnormal fatigue on exertion," said Andelfinger.

According to Florian Wunnemann, PhD and the lead author of the study, to understand the role of this gene, "we had to use a preclinical model that presented the same pathological features as our young patients. This helped us to analyze the function of this gene in great detail and to define the mechanisms of the disease."

"By using single-cell sequencing, a new technology that establishes the genetic profile of a single cell -- in heart tissue. For example, we can very precisely define the type of cell behind the pathology. This really helped us demonstrate the molecular consequences of the mutation," he added.

Indeed, the data shows that the mutation in patients changes the regulatory mechanism in the valves. One thing leading to another, an Israeli team of researchers at the Hadassa Hebrew University Medical Center that had identified exactly the same gene contacted Dr Andelfinger and his team, lending support to their hypothesis.

An estimated 4,000 valve surgeries are performed in Canada each year, and this figure is constantly rising due to the ageing of the population. On top of the pain and suffering of patients and their families, the economic burden is close to 1 billion USD a year. The discovery of the genetic causes of some 40 rare diseases by the teams at CHU Sainte-Justine in recent years is a shining example of this expertise.