It may soon be possible to use a simple blood test to identify whether you are at greater risk of suffering from a heart attack. Two recent studies have revealed new insights into the connection between specific genetic variants and the increased risk of heart disease.
Firstly, a research group made up of Canadian and British researchers has identified specific genes which are associated with the heightened risk of heart attack. The team, led by Dr Sonia Anand, a professor in the Michael G DeGroote School of Medicine at McMaster University, Canada, extracted DNA over 8,000 individuals from five different ethic groups - European, south Asian, Arab, Iranian and Nepalese.
In this study 1,536 SNPs (single nucleotide polymorphisms) were genotyped. SNPs are variations in DNA which occur within genes that can, in some cases, alter the expression of other genes. From this research it was concluded that 13 common SNPs were associated with the risk factors of heart disease and one SNP variant was connected independently with the risk of heart attack. Dr Anand explained that 'the unique contribution of our study is that we demonstrate that common genetic variants are indeed common across five ethic groups'. She also emphasised that although genetic variants did have 'a small independent contribution to the risk of heart attack', the nine risk factors (high cholesterol, diabetes, hypertension, abdominal obesity, tobacco, physical inactivity, psychosocial stressors, low fruit and vegetable intake and no alcohol consumption) 'account for the vast majority of heart attacks'.
A second study has revealed findings of a genome-wide study which compared the genomes of 3000 people who had suffered heart attacks earlier in life (men under 50 and women under 60), with 3000 people who had not suffered heart attacks. The research found that SNPs in nine regions of the genome were connected with risk of early heart attack; 20 per cent of the participants who had the most unfavourable genetic profile were more than twice as likely to suffer from early heart attacks, in comparison to the 20 per cent with the best genetic profile.
In contrast to Dr Anand's reflections on the small relevance of genetic variants, this research would seem to provide explanation as to why some people suffer heart attacks at an early age despite healthy lifestyles, while others with relatively unhealthy life styles manage to avoid earlier heart attacks.
Professor Nilesh Samani, British Heart Foundation Professor of Cardiology at the University of Leicester, UK, commented that 'this is a major advance in understanding the familial basis of coronary heart disease ... understanding how they increase risk of heart attacks may provide new means of preventing or treating coronary heart disease'.