Researchers  at the National Heart Centre Singapore (NHCS) believe they are the first in the world to correct a potentially fatal genetic heart disorder with drugs.

The disorder, long QT syndrome 2, affects the heart's electrical activity and may cause sudden and dangerous rhythms in response to exercise or stress.

Primarily an inherited condition and difficult to diagnose, it is estimated to affect one in 5,000 people in Singapore. Often, it is a cause of sudden cardiac death in the young.

The disease is typically managed through a combination of lifestyle changes - such as avoiding strenuous activity - and medical intervention, including implants which deliver electrical shocks to reset the heart rhythm.

But Associate Professor Philip Wong, the director of the NHCS' research and development unit, hopes his team is on track to produce a drug therapy within five to eight years which could lead to a "permanent reversal of the genetic condition".

After a year testing various drugs on beating heart cells made from human skin stem cells, the team discovered that a drug known as ALLN could correct the effects of the syndrome.

"We have mimicked a patient's disease condition in a petri dish, understood the mechanism of long QT syndrome 2 on this platform, and successfully tailored a drug that reverses the entire condition," said Prof Wong.

The researchers are now looking to conduct clinical trials to test the drug's side effects in humans. But they will have to collaborate with research outfits around the world as patients with the syndrome are rare here.

Identifying those born with the condition, which is caused by a gene

mutation, is also difficult since most do not show any signs or symptoms until their teens. But when symptoms, which can include fainting spells and seizures, do appear, studies show that half die within 10 years.

Dr Tan Chong Hiok, a cardiologist at Mount Elizabeth Hospital, believes a drug therapy for the condition "would be great". "Current treatment such as implants is expensive and does not treat the root cause," he explained.

"But it is going to be very difficult to set up large clinical trials quickly for something this rare and it might take a decade to get the drug on the market."