APOLIPOPROTEIN-E POLYMORPHISM IN A FRENCH-CANADIAN POPULATION OF NORTHEASTERN QUEBEC - ALLELE FREQUENCIES AND EFFECTS ON BLOOD LIPID AND LIPOPROTEIN LEVELS

Apolipoprotein E phenotypes and plasma lipid and lipoprotein levels we re determined in 435 individuals (233 men, 202 women) of French Canadi an descent living in northeastern Quebec, This region is known for its high frequency of mutant genes responsible for rare genetic disorders . Total cholesterol, low-density lipoprotein (LDL) cholesterol, high-d ensity lipoprotein (HDL) cholesterol, and triglyceride levels were adj usted for age, height, weight, body mass index (BMI), and waist circum ference using regressions performed separately in men and in premenopa usal and postmenopausal women, The APOE allele frequencies in this pop ulation-based sample were 0.137, 0.749, and 0.114 for the 2, *3, and 4 alleles, respectively. APOE2 (APOE 2,2 and APOE 3,2) subjects had l ower total and LDL cholesterol levels than APOE3 (APOE 3,3) subjects, In APOE4 (APOE 4,3 and APOE 4,4) men and postmenopausal women levels o f total and LDL cholesterol and triglycerides were significantly highe r than in the corresponding APOE3 subjects. The 2 allele was also fou nd to be associated with higher triglyceride levels in men and postmen opausal women, Men of the APOE4 group also presented lower HDL cholest erol levels. Although the impact of APOE polymorphism on blood lipid a nd lipoprotein levels in this French Canadian population is similar to what has been reported in other white populations, the frequency of t he 2 allele is among the highest ever reported. This finding is discu ssed in terms of the founder effect characterizing the Quebec populati on.