Sons can inherit heart disease from dad: Study - Times of India

This increased risk is irrespective of traditional cardiovascular risk factors such as high blood pressure or cholesterol. The study was led by Dr Maciej Tomaszewski from University of Leicester, the UK, and Dr Fadi Charchar from University of Ballarat, Australia. They concluded, "Our study is the first to evaluate associations between main Y chromosome lineages and CAD as well as its underlying risk factors. It has revealed that the Y chromosome might have a magnified effect on men beyond sex determination despite the small number of genes it harbours in the human genome."

The authors, however, added that future re-sequencing and functional experiments will be needed to identify the causative variants underlying the increased susceptibility to CAD in carriers of haplogroup I and to decipher complex interplay among human Y chromosome, immunity and cardiovascular disease. Cardiologist Dr Pramod Kumar from Fortis Hospital says, "Even after taking other known risk factors - such as age, diabetes, smoking, alcohol, socio economic status, high blood pressure and cholesterol - into account, the haplogroup I variant increased men's CAD risk by 50% compared to those without it. This may be because men with haplogroup I tend to have more sensitive immune systems, which can trigger damaging inflammation of heart tissue."

CAD means narrowing of vessels delivering blood to heart, or difficulties for oxygen can to reach the vital organ. This can lead to angina symptoms that could cause heart attacks. The authors' genotyped 11 markers of the male-specific region of the Y chromosome in 3,233 biologically unrelated British men. On the basis of this information, each Y chromosome was tracked back into one of 13 ancient lineages defined as haplogroups.

Of the nine haplogroups identified, two (R1b1b2 and I) accounted for roughly 90% of the Y chromosome variants among British men. Carriers of haplogroup I (15% to 20% of the British male population) had about a 50% higher age-adjusted risk of CAD than did men with other Y chromosome in the other lineages.

Dr Virginia Miller, Mayo Clinic, USA, says, "It would be interesting to examine whether existing algorithms assessing individual risk of coronary artery disease for men could be improved by changing the question 'Did your mother or father have a heart attack before age 60?' to 'Did your father have a heart attack before the age of 60?' Both sex and family matter in inheritance of coronary artery disease."

The haploid Y chromosome contains the smallest number of genes. The main part of the Y chromosome is transmitted intact from father to son, and contains single and multi-copy genes that encode about 27 distinct proteins. The biological role of the Y chromosome is to impart male characteristics.