Why we are not able to find the coronary heart disease gene - apoE as an example.

The apoprotein E gene ranks among the most discussed candidate genes for cardiovascular disease. We studied whether the association between apoprotein E gene polymorphism and manifestation of acute coronary syndrome is modulated by the presence/absence of traditional cardiovascular risk factors. The population under study were 1066 patients (men under 65 years) admitted between 2006- 2009 to five coronary care units in Prague (GENetic DEtermination of Myocardial Infarction in Prague) and the control population (1066 age-matched men selected from the Czech population sample). The frequency of disadvantage genotype E4+ was significantly higher (P < 0.01) in acute coronary syndrome patients (22.38 %) than in controls (16.76 %). When the acute coronary syndrome group was step by step limited to non-smokers, non-diabetics and normotensive individuals, the odds ratio displayed a gradual increase from 1.35 (for the entire group) through 1.48 (non-smokers), 1.53 (non-smokers+non-diabetics) to 1.71 (non-smokers+non-diabetics+normotensives). The effect of the apoprotein E gene on the individual risk of acute coronary syndrome is nonhomogenous within the patient groups. This association of apoprotein E gene with acute coronary syndrome is strongly modified by the presence/absence of traditional cardiovascular factors of atherosclerosis in a high-risk Czech population.