A newly discovered gene mutation may be the answer behind the mysterious cardiac deaths in otherwise healthy young people, research points out.
Frequently over the last years, healthy young people have experienced sudden cardiac death, and many doctors are confused as to why the heart abruptly stopped beating.
Researchers from Denmark have found a gene mutation that can cause serious heart disease or sudden cardiac death in both adults and children.
Professor Anders Borglum and his team, whose study was published in The American Journal of Human Genetics, believe their new discovery could explain some extremely publicized cases of young athletes suddenly dropping dead during sporting events.
The causes of these deaths are normally put down to “unknown heart disease”. These cases cannot directly be attributed to this new disease gene just yet, but the possibility is not unimaginable.
This particular study was the result of years of detective work. A family in Sweden was suffering from heart issues, with two healthy boys ages 13 and 15 both experiencing sudden cardiac death during sporting events. Doctors were certain that the heart problems had to be hereditary. However, the family did not have the genetic mutation that was known to cause cardiac conditions. The Swedish doctors decided to collaborate with Danish researchers to solve this puzzle.
Associate Professor Mette Nyegaard, of Aarhus University’s Department of Human Genetics, who was involved in the project said:
“We received blood samples from a number of the Swedish family members, we then started scanning their entire genome. It was an arduous task, but we eventually managed to zoom in on one particular gene mutation that all the family members had in common.”
The mutation was located in the calmodulin, a gene which acts as rules for the body’s production of a critical protein. Scientists have previously been aware of certain genes which can cause sudden cardiac death, but calmodulin was never one of them until now.
The researchers are currently studying the prevalence of the newly discovered gene mutation. They examine blood samples of large groups of patients with heart problems from unknown causes.
Humans carry three separate kinds of calmodulin genes, but scientists have only found mutations in one, called calmodulin 1. They are interested to see if mutations are the cause in the other calmodulins genes as well.
Associate Professor Michael Toft Overgaard, of Aalborg University’s Department of Biotechnology, Chemistry and Environmental Engineering, explains:
“The calmodulin protein usually functions like a kind of sensor which measures the concentration of calcium in the body’s cells. The concentration of calcium is of immense importance to the heart because it determines when the heart contracts and beats.”
Overgaard conducted a series of experiments to find out how the mutated calomodulin proteins behave. The mutated calmodulin genes were put into bacteria with the help of DNA technology, and ended up having the same abnormal genes that cause the heart troubles in the Swedish family. The flawed calomodulin protein formed by the bacteria could not bind to calcium in the same way as normal calmodulin proteins.
Overgaard concluded: “Our theory is that these gene mutations cause heart disease because the ability to measure the calcium concentration in the heart cells simply isn’t optimal. And that could cause irregular heartbeats.”.
Finding this mutation helped the researchers exclude several family members who may suffer from this problem, because they did not have this gene mutation. This discovery can help prevent deaths by identifying this faulty gene. People who carry the mutation could be better equipped with a pacemaker if their heart abruptly stops beating. The scientists plan to continue their research to reveal specifically which molecular mechanisms are affected by calmodulin mutations.
Written by Kelly Fitzgerald