Archived Comments for:
Genetic study of common variants at the Apo E, Apo AI, Apo CIII, Apo B, lipoprotein lipase (LPL) and hepatic lipase (LIPC) genes and coronary artery disease (CAD): variation in LIPC gene associates with clinical outcomes in patients with established CAD
Apolipoprotein E allele frequency is different in various populations with coronary artery disease and healthy subjects
Genovefa Kolovou, Onassis Cardiac Surgery Center
10 February 2004
Apolipoprotein E allele frequency is different in various populations with coronary artery disease and healthy subjects
Genovefa D. Kolovou1 MD, Associate Director
Katherine K. Anagnostopoulou1 MSc Research Associate
Nikos Yiannakouris2 PhD, Research Associate
Dennis V. Cokkinos1 MD, Professor of Cardiology, Athens University Medical School, Director.
1Cardiology Department, Onassis Cardiac Surgery Center, Athens, Greece
2Harokopio University, Athens, Greece
Short Title: Apolipoprotein E allele frequency
Corresponding author
Genovefa D. Kolovou, MD, PhD, FESC
Onassis Cardiac Surgery Center
356 Sygrou Ave, 176 74 Athens, Greece
Tel: +30 210 9493520, Fax: +30 210 9493336
E-mail: Genkolovou@mail.gr
We have read with great interest the article of Baroni M and colleagues (1) describing association of apolipoprotein (apo) E apo E, apo AI, apo CIII, lipoprotein lipase, and hepatic lipase gene polymorphisms with clinical outcomes of coronary artery disease (CAD) and healthy subjects, in Italian population. We would like to add some comments and observations concerning the other populations that may be of interest.
Baroni and associates genotyped a total of 102 CAD patients and 104 healthy individuals. The reported apo E allele frequencies were ε2: 2.6%, ε3: 91.4%, ε4: 6.0% in the control group and ε2: 8.0%, ε3: 84.0%, ε4: 8.0% in the CAD group. The apo ε2 allele showed a significantly higher frequency in the CAD group compared to the control group. Our study (2) was based on 267 CAD patients, originating from various parts of Greece, from which 124 had myocardial infarction (MI), while 143 had CAD without MI. Our control group was comprised of 240 Greek healthy individuals with no family history of CAD or MI. Among the control subjects, we found that the apo ε2, ε3 and ε4 allele frequencies were 8.1%, 81.7% and 10.2%, respectively. These values are similar to those in other Southern European populations, like the Italians (3) (ε2: 7.3%, ε3: 83.3%, ε4: 9.4%) and the French (4) (ε2: 7.9%, ε3: 80.1%, ε4: 12.0%). The estimated ε2 allele frequency in the Greek healthy population was similar to the average Caucasian value (8.0%) (5). In contrast, the ε4 allele was less prevalent compared to most Northern European populations [24.4% in Filand (6), 20.3% in Sweden (7)] where the ε4 allele may, in part, account for the higher CAD mortality rates. Among the CAD group of our report, the apo ε2, ε3 and ε4 allele frequencies were 3.9%, 85.8% and 10.3%, respectively. The apo ε2 allele was twice higher in healthy subjects compared to CAD patients (p=0.02). In the study of Baroni and associates the opposite results were found. On the other hand, similar to Baroni and associates there was no difference in the distribution of apo ε4 allele between CAD patients and healthy subjects. This finding, which is in contradiction with what has been observed in most other populations, suggests that the positive association of the apo ε4 allele with the risk of CAD may not be extended to all ε4 allele carriers worldwide. Allele as well as genotype frequencies may vary in different populations. This becomes more apparent by analyzing the data of Baroni and associates and ours, where two different populations although geographically very close are compared.
References
1. Baroni MG, Berni A, Romeo S, Arca M, Tesorio T, Sorropago G, Di Mario U, Galton DJ. Genetic study of common variants at the Apo E, Apo AI, Apo CIII, Apo B, lipoprotein lipase (LPL) and hepatic lipase (LIPC) genes and coronary artery disease (CAD): variation in LIPC gene associates with clinical outcomes in patients with established CAD. BMC Med Genet. 2003 10;4:8.
2. Kolovou G, Yiannakouris N, Hatzivassiliou M, Malakos J, Daskalova D, Hatzigeorgiou G, Cariolou MA, Cokkinos DV. Association of apolipoprotein E polymorphism with myocardial infarction in Greek patients with coronary artery disease. Cur Med Res Opin 2002; 18: 118-124.
3. James RW, Boemi MG, Giansanti R, Fumelli P, Pometta D. Under-expression of the apolipoprotein E4 isoform in an Italian population. Arterioscler Thromb 1993; 13: 1456-1459.
4. Bailleul S, Couderc R, Landais, Lefevre G, Raichvarg D, Etienne J.V. Direct phenotyping of human apolipoprotein E in plasma: Application to population frequency distribution in Paris (France). Hum Hered 1993; 43: 159-165.
5. Davignon J, Gregg RE, Sing CF. Apolipoprotein E polymorphism and atherosclerosis. Atherosclerosis 1988; 8: 1-21.
6. Ehnholm C, Lukka M, Kuusi T, Nikkila E, Utermann G.. Apolipoprotein E polymorphism in the Finnish population: Gene frequencies and relation to lipoprotein concentrations. J Lipid Res 1986; 27: 227-235.
7. Eggertsen G, Tegelman R, Ericsson S, Ericsson S, Angelin B, Berglund. Apolipoprotein E polymorphism in a healthy Swedish population: Variation of allele frequency with age and relation to serum lipid concentrations. Clin Chem 1993; 39: 2125-2129.
Apolipoprotein E allele frequency is different in various populations with coronary artery disease and healthy subjects
10 February 2004
Apolipoprotein E allele frequency is different in various populations with coronary artery disease and healthy subjects
Genovefa D. Kolovou1 MD, Associate Director
Katherine K. Anagnostopoulou1 MSc Research Associate
Nikos Yiannakouris2 PhD, Research Associate
Dennis V. Cokkinos1 MD, Professor of Cardiology, Athens University Medical School, Director.
1Cardiology Department, Onassis Cardiac Surgery Center, Athens, Greece
2Harokopio University, Athens, Greece
Short Title: Apolipoprotein E allele frequency
Corresponding author
Genovefa D. Kolovou, MD, PhD, FESC
Onassis Cardiac Surgery Center
356 Sygrou Ave, 176 74 Athens, Greece
Tel: +30 210 9493520, Fax: +30 210 9493336
E-mail: Genkolovou@mail.gr
We have read with great interest the article of Baroni M and colleagues (1) describing association of apolipoprotein (apo) E apo E, apo AI, apo CIII, lipoprotein lipase, and hepatic lipase gene polymorphisms with clinical outcomes of coronary artery disease (CAD) and healthy subjects, in Italian population. We would like to add some comments and observations concerning the other populations that may be of interest.
Baroni and associates genotyped a total of 102 CAD patients and 104 healthy individuals. The reported apo E allele frequencies were ε2: 2.6%, ε3: 91.4%, ε4: 6.0% in the control group and ε2: 8.0%, ε3: 84.0%, ε4: 8.0% in the CAD group. The apo ε2 allele showed a significantly higher frequency in the CAD group compared to the control group. Our study (2) was based on 267 CAD patients, originating from various parts of Greece, from which 124 had myocardial infarction (MI), while 143 had CAD without MI. Our control group was comprised of 240 Greek healthy individuals with no family history of CAD or MI. Among the control subjects, we found that the apo ε2, ε3 and ε4 allele frequencies were 8.1%, 81.7% and 10.2%, respectively. These values are similar to those in other Southern European populations, like the Italians (3) (ε2: 7.3%, ε3: 83.3%, ε4: 9.4%) and the French (4) (ε2: 7.9%, ε3: 80.1%, ε4: 12.0%). The estimated ε2 allele frequency in the Greek healthy population was similar to the average Caucasian value (8.0%) (5). In contrast, the ε4 allele was less prevalent compared to most Northern European populations [24.4% in Filand (6), 20.3% in Sweden (7)] where the ε4 allele may, in part, account for the higher CAD mortality rates. Among the CAD group of our report, the apo ε2, ε3 and ε4 allele frequencies were 3.9%, 85.8% and 10.3%, respectively. The apo ε2 allele was twice higher in healthy subjects compared to CAD patients (p=0.02). In the study of Baroni and associates the opposite results were found. On the other hand, similar to Baroni and associates there was no difference in the distribution of apo ε4 allele between CAD patients and healthy subjects. This finding, which is in contradiction with what has been observed in most other populations, suggests that the positive association of the apo ε4 allele with the risk of CAD may not be extended to all ε4 allele carriers worldwide. Allele as well as genotype frequencies may vary in different populations. This becomes more apparent by analyzing the data of Baroni and associates and ours, where two different populations although geographically very close are compared.
References
1. Baroni MG, Berni A, Romeo S, Arca M, Tesorio T, Sorropago G, Di Mario U, Galton DJ. Genetic study of common variants at the Apo E, Apo AI, Apo CIII, Apo B, lipoprotein lipase (LPL) and hepatic lipase (LIPC) genes and coronary artery disease (CAD): variation in LIPC gene associates with clinical outcomes in patients with established CAD. BMC Med Genet. 2003 10;4:8.
2. Kolovou G, Yiannakouris N, Hatzivassiliou M, Malakos J, Daskalova D, Hatzigeorgiou G, Cariolou MA, Cokkinos DV. Association of apolipoprotein E polymorphism with myocardial infarction in Greek patients with coronary artery disease. Cur Med Res Opin 2002; 18: 118-124.
3. James RW, Boemi MG, Giansanti R, Fumelli P, Pometta D. Under-expression of the apolipoprotein E4 isoform in an Italian population. Arterioscler Thromb 1993; 13: 1456-1459.
4. Bailleul S, Couderc R, Landais, Lefevre G, Raichvarg D, Etienne J.V. Direct phenotyping of human apolipoprotein E in plasma: Application to population frequency distribution in Paris (France). Hum Hered 1993; 43: 159-165.
5. Davignon J, Gregg RE, Sing CF. Apolipoprotein E polymorphism and atherosclerosis. Atherosclerosis 1988; 8: 1-21.
6. Ehnholm C, Lukka M, Kuusi T, Nikkila E, Utermann G.. Apolipoprotein E polymorphism in the Finnish population: Gene frequencies and relation to lipoprotein concentrations. J Lipid Res 1986; 27: 227-235.
7. Eggertsen G, Tegelman R, Ericsson S, Ericsson S, Angelin B, Berglund. Apolipoprotein E polymorphism in a healthy Swedish population: Variation of allele frequency with age and relation to serum lipid concentrations. Clin Chem 1993; 39: 2125-2129.
Competing interests
None declared