Recent research has shown that inactivation of a single gene reduces the risk of heart attack by 50%.
It is widely known that lowering blood LDL cholesterol can reduce the risk of heart disease.
The widely prescribed statins prevent the body from producing cholesterol. In contrast, the drug ezetimibe prevents dietary cholesterol from being absorbed into the bloodstream.
Although ezetimibe is known to effectively lower blood cholesterol levels, it has not been conclusively proven that it also reduces the risk of heart disease.
Ezetimibe works by inactivating a protein produced by the NPC1L1 gene.
The latest research involved sequencing the NPC1L1 gene in around 113,000 people from multiple existing studies to find naturally occurring mutations that stop production of the NPC1L1 protein.
Researchers then investigated whether there was a link between inactivation of the NPC1L1 gene and plasma lipid levels or the risk of coronary heart disease.
Only around 1 in 650 people were found to have one inactive version of the NPC1L1 gene. There were no cases of inactivating mutations being present in both NPC1L1 genes.
LDL cholesterol levels were on average 10% lower among people with only one working copy of the gene compared with people having two working copies of the gene.
Furthermore, the risk of coronary heart disease among people with an inactive copy of the NPC1L1 gene was half that seen in people with two functional copies of the gene.
The individuals with the rare gene mutation did not appear to differ from the larger population in any other ways, including in measures of blood pressure, body mass index and rates of diabetes.
This research shows that naturally occurring inactivation of NPC1L1 is associated with both reduced LDL cholesterol levels and a reduced risk of coronary heart disease.
It remains to be determined whether pharmacological therapies that inhibit NPC1L1 can provide similar benefits.
The reduction in LDL cholesterol observed in this analysis is comparable to that seen in patients taking ezetimibe so hopes are high.
Dr Sekar Kathiresan commented:
Protective mutations like the one we’ve just identified for heart disease...can teach us about the underlying causes of disease and point to important drug targets.
Dr Nathan Stitziel explained, " When people have one copy of a gene not working, it’s a little like taking a drug their entire lives that is inhibiting this gene...this genetic analysis gives us some confidence that targeting this gene should reduce the risk of heart attack”.