February 9th, 2012
The Y Chromosome May Explain Why Men Have Earlier Coronary Disease
The earlier onset of coronary artery disease in men has long provoked speculation and research. Now a new study in the Lancet suggests that common variations in the Y chromosome (which is transmitted directly from father to son and does not undergo recombination) may play an important role in the increased risk seen in men.
Using genetic information on the Y chromosome, an international team of researchers identified nine different ancient lineages — haplogroups — in 3233 British men. Two of the haplogroups accounted for nearly 90% of the Y chromosome variants in subjects, and carriers of one of these haplogroups — haplogroup I — had a 50% increase in the risk of coronary artery disease compared to men with other haplotypes. This increase in risk was independent of other known risk factors. The investigators noted that haplogroup I appeared to exert a powerful effect on genes relating to inflammation and immunity. They further noted that haplotype I is generally more prevalent in northern than in southern Europe, and that this distribution is paralleled by an increased risk of coronary artery disease in northern Europe.
In an accompanying comment, Virginia Miller writes that the results of the study are “exciting because they identify a genetic haplotype linking response to infection (adaptive immunity) rather than innate immunity with perhaps an exaggerated inflammatory response and cardiovascular disease in men.”