Men may inherit a form of heart disease from their fathers via Y chromosome

Although heart disease is the leading killer of women as well as of men, two heart disease patients out of every three are male, and heart disease strikes men 10 to 15 years earlier than it does women. No one really knows why.

Now, a new study reports that part of the answer may lie in the Y chromosome, the one chromosome unique to men.

In the study, published on Wednesday in The Lancet, researchers found that nearly all British men have one of two variants of a cluster of genes on their Y chromosome. Those with one of the variants had a 50 per cent increased risk of heart disease compared with men with the other variants. This risk was independent of traditional factors like cholesterol, smoking and diabetes.

The study needs to be replicated, researchers say, and while it raises intriguing hypotheses, it is not definitive.

The researchers also do not yet know which individual genes in the cluster are responsible for the increased risk, nor do they know why the genes have this effect. 

Everyone knows men who did all the wrong things — ignored their cholesterol levels, smoked — and yet were spared heart disease. And everyone knows men who were careful about their diet, controlled their cholesterol levels and blood pressure and did not smoke, yet died young from heart attacks.

The message of the new study, was that for some of those unlucky men, “yes indeed, they did have inheritable factors that independently caused death.” And when a screening test is developed to find those Y chromosome gene clusters, and researchers have a better understanding of how they act, it may be possible to protect some of them from having heart attacks.

A heart disease researcher  said it was also possible that simply having a Y chromosome instead of two X chromosomes, as women have, increased heart disease risk. The extra X could be protective.

Heart disease researchers have generally ignored the role of the Y chromosome, assuming it was mostly involved in determining malenes . He suggested the cluster of genes on the Y chromosome of the men with lower risk may help control inflammation, a process that is part of the formation of atherosclerotic plaques.

 A lot more work needs to be done on the gene cluster. The association between the gene cluster and heart disease risk needed to be confirmed.