The research showed that around one in 100 people carry a faulty gene which could trigger a dangerous heart condition in seemingly healthy people, if the heart is placed under abnormal stress, such as through pregnancy or high blood pressure.
We found that those with mutations have an enlarged heart, and in a pattern similar to that seen in heart failure patients. This may impact as many as 35 million people around the world.
– Dr Antonio de Marvao Study author
The team, who studied both rats and people, believe the findings suggest around 75 million people worldwide could be at risk of developing heart failure if their hearts are placed under abnormal stress. It may be that the stress caused by pregnancy, a viral infection of the heart, alcoholism or high blood pressure could trigger the heart problems.
They found that although the rats appeared healthy, placing abnormal stress on the heart triggered a rare heart muscle condition called dilated cardiomyopathy (DCM), which causes heart failure.
Dilated cardiomyopathy is a disease of the heart muscle where it becomes stretched and thin, and is unable to pump blood around the body efficiently. It affects 1 in 250 people in the UK and is the most common cause of heart transplant.
As expected, 14 people (1 per cent) had the titin gene mutation. From looking at the 3D heart models, the scientists found that healthy people with the titin mutations had a slightly enlarged heart, compared with those without the mutations.
This supports the findings in rats which suggest titin mutations, even in the absence of dilated cardiomyopathy, are having an impact on the heart.