Scientists in the UK have shown that genetic variations in the Y chromosome affect a male’s risk of coronary heart disease. It is well known that males have a higher incidence of coronary heart disease than females due, in part, to the Y chromosome they inherit from their fathers. To investigate the role of the Y chromosome further, a team from the University of Leicester carried out research to determine whether genetic variations in the Y-chromosome affect risk for males.
Not all Y chromosomes are the same. There are variants within the male gender called “Y-haplogroups”, which are usually associated with specific geographic regions and tend to indicate the origin of the ancestral line. Professor Nilesh Samani explains the background to the project that was funded by the British Heart Foundation, “We set out to determine if men with differing types of Y chromosome were at differing risk of heart disease. We tested nearly 3,000 British males, and found that those carrying the I-haplogroup variant had a 55 percent higher risk of coronary heart disease.”
Of the 3,000 men tested, 1,295 were the cohort group of those with coronary heart disease and the rest were the control group. The Y-haplogroup was identified in all men, and the results showed that those in the I-haplogroup had an approximately 55 percent higher risk of coronary heart disease compared to the others. The association of the I-haplogroup with coronary heart disease was independent of, and not explained by, traditional heart risk factors such as cholesterol, high blood pressure and smoking.
Commonly found in central, eastern and northern Europe, the I-haplogroup is carried by about 13 percent of British men. Its origin is thought to be of the Gravettian culture, which arrived in Europe from the Middle East about 25,000 years ago. Since the I-haplogroup is not so prevalent in southern parts of Europe, an interesting speculation is whether it contributes to the higher levels of coronary heart disease in the north compared to the south – however, this requires further research and testing.
What is clear from this study though, is that men carrying the I-haplogroup are more likely to suffer from coronary heart disease than men with other Y-haplogroups.