(From BBC News)
Scientists say they have identified genes that cause a deadly heart condition that can only be cured by transplants of the heart or lungs.
Pulmonary arterial hypertension kills 50% of those affected within five years, but little was known about what caused the condition in some people.
Now experts say they have discovered five genes that cause the illness.
Pulmonary arterial hypertension (PAH) currently affects around 6,500 people in the UK and causes the arteries carrying blood from the heart to their lungs to stiffen and thicken, ultimately leading to heart failure.