You could be at risk of a genetic condition that causes high cholesterol and not even know it, warns a new study. Familial hypercholesterolemia, it says, can go unnoticed for several generations – putting the people who have it at a dangerously high risk of heart attacks and stroke.
The condition affects 1 in 200–250 people worldwide, causing high levels of low-density lipoprotein (LDL) cholesterol from birth. This is the ‘bad’ cholesterol that drives plaque buildup in your arteries. Yet, scientists say, standard testing often doesn’t pick up on it.
To find out how much familial hypercholesterolemia goes undiagnosed, the researchers behind the new study, from the Mayo Clinic in the US, studied the data of 84,000 people. Specifically, the results from exome sequencing – a genetic test that analyses the parts of DNA responsible for coding proteins.
They found that 419 of them were at risk of familial hypercholesteremia – but 90 per cent of these people weren’t aware that they had it.
What’s worse, one in five of them had already developed coronary artery disease.
According to the study, these people would likely not have found out about their condition via standard genetic testing.
Currently, in the US, genetic testing is only given to those who already have high enough cholesterol levels or a recorded family history of high levels – an issue the Mayo Clinic researchers called a “blind spot” in national guidelines. Seventy-five per cent of those diagnosed via the study wouldn’t have met this criteria.
The study advises that routine screening could catch the condition and save lives, yet other scientists caution that this isn’t so straightforward.
“The issue is that the cost to screen everyone with genetic testing required is simply too high, and so we have to make some form of thresholds,” cardiometabolic medical researcher Prof Naveed Sattar told BBC Science Focus.
“Wider screening for familial hypercholesterolemia will only happen if the costs of testing come down markedly and, even then, more people would need to come forwards to have bloods done and be happy to have their genes tested.”
Most people with familial hypercholesterolemia show no symptoms. However, Sattar says, yellowish deposits under the skin or (in under-45-year-olds) a greyish white ring around the eye’s cornea can be signs of the condition.
“But most have no visible signs – if people have a strong family history of premature heart attacks (especially if a first degree relative had a heart attack under 50), they should get their lipids checked sooner than routine screening in middle age occurs.”
The study was published in journal Circulation: Genomic and Precision Medicine.
Read more: