Key points are not available for this paper at this time.
The genetic variability of apolipoprotein E (apoE) influences plasma lipoprotein levels, and allele frequencies differ between African Americans and Caucasians. As African Americans have higher lipoprotein a (Lpa) levels than Caucasians, we investigated the effects of the apoE gene on allele-specific apolipoprotein a (apoa) levels across ethnicity. We determined apoa sizes, allele-specific apoa levels (i.e., levels associated with alleles defined by size), and the apoE gene polymorphism in 231 African Americans and 336 Caucasians. African Americans, but not Caucasians, with the apo E2 genotype had lower levels of Lpa compared with those with the apo E4 genotype (9.6 vs. 11.2 nmol/l; P = 0.034, expressed as square root levels). Distribution of apoa alleles across apoE genotypes were similar between African Americans and Caucasians. Among African Americans with large apoa, the allele-specific apoa level was significantly lower among ε2 carriers compared with ε3 or ε4 carriers (5.4 vs. 6.6 and 7.4 nmol/l, respectively; P < 0.005, expressed as square root levels). In contrast, there was no significant difference in allele-specific apoa levels across apoE genotypes among Caucasians. For large apoa sizes, apoE genotype contributed to the observed African American-Caucasian differences in allele-specific apoa levels. The genetic variability of apolipoprotein E (apoE) influences plasma lipoprotein levels, and allele frequencies differ between African Americans and Caucasians. As African Americans have higher lipoprotein a (Lpa) levels than Caucasians, we investigated the effects of the apoE gene on allele-specific apolipoprotein a (apoa) levels across ethnicity. We determined apoa sizes, allele-specific apoa levels (i.e., levels associated with alleles defined by size), and the apoE gene polymorphism in 231 African Americans and 336 Caucasians. African Americans, but not Caucasians, with the apo E2 genotype had lower levels of Lpa compared with those with the apo E4 genotype (9.6 vs. 11.2 nmol/l; P = 0.034, expressed as square root levels). Distribution of apoa alleles across apoE genotypes were similar between African Americans and Caucasians. Among African Americans with large apoa, the allele-specific apoa level was significantly lower among ε2 carriers compared with ε3 or ε4 carriers (5.4 vs. 6.6 and 7.4 nmol/l, respectively; P < 0.005, expressed as square root levels). In contrast, there was no significant difference in allele-specific apoa levels across apoE genotypes among Caucasians. For large apoa sizes, apoE genotype contributed to the observed African American-Caucasian differences in allele-specific apoa levels. A high plasma level of lipoprotein a (Lpa) is an independent risk factor for cardiovascular disease (1Utermann G. The mysteries of lipoprotein(a). Science. 1989; 246: 904-910Google Scholar, 2Stein J.H. Rosenson R.S. Lipoprotein Lp(a) excess and coronary heart disease. Arch. Intern. Med. 1997; 157: 1170-1176Google Scholar, 3Danesh J. Collins R. Peto R. Lipoprotein(a) and coronary heart disease. Meta-analysis of prospective studies. Circulation. 2000; 102: 1082-1085Google Scholar). Lpa levels are to a major extent regulated by genetic factors (4Boerwinkle E. Leffert C.C. Lin J. Lackner C. Chiesa G. Hobbs H.H. Apolipoprotein(a) gene accounts for greater than 90% of the variation in plasma lipoprotein(a) concentrations. J. Clin. Invest. 1992; 90: 52-60Google Scholar). Like LDL, Lpa has one molecule of apolipoprotein B-100, which is covalently bound to a carbohydrate-rich protein, apolipoprotein a (apoa) (5Gaubatz J.W. Heideman C. Gotto Jr., A.M. Morrisett J.D. Dahlen G.H. Human plasma lipoprotein a. Structural properties. J. Biol. Chem. 1983; 258: 4582-4589Abstract Full Text PDF PubMed Google Scholar, 6Scanu A.M. Edelstein C. Learning about the structure and biology of human lipoprotein a through dissection by enzymes of the elastase family: facts and speculations. J. Lipid Res. 1997; 38: 2193-2206Google Scholar). The size of the apoa gene is highly variable, resulting in a size variation of the apoa protein, as manifested in a variable number of kringle 4 (K4) repeats (1Utermann G. The mysteries of lipoprotein(a). Science. 1989; 246: 904-910Google Scholar, 7McLean J.W. Tomlinson J.E. Kuang W.J. Eaton D.L. Chen E.Y. Fless G.M. Scanu A.M. Lawn R.M. cDNA sequence of human apolipoprotein(a) is homologous to plasminogen. Nature. 1987; 330: 132-137Google Scholar). There is an inverse relationship between apoa size and Lpa levels, as smaller apoa sizes in general are associated with higher plasma Lpa levels. However, for a given size, there is considerable interindividual variation in Lpa levels (4Boerwinkle E. Leffert C.C. Lin J. Lackner C. Chiesa G. Hobbs H.H. Apolipoprotein(a) gene accounts for greater than 90% of the variation in plasma lipoprotein(a) concentrations. J. Clin. Invest. 1992; 90: 52-60Google Scholar, 8Kraft H.G. Lingenhel A. Pang R.W. Delport R. Trommsdorff M. Vermaak H. Janus E.D. Utermann G. Frequency distributions of apolipoprotein(a) kringle IV repeat alleles and their effects on lipoprotein(a) levels in Caucasian, Asian, and African populations: the distribution of null alleles is non-random. Eur. J. Hum. Genet. 1996; 4: 74-87Google Scholar, 9Gaw A. Boerwinkle E Cohen J.C. Hobbs H.H. Comparative analysis of the apo(a) gene, apo(a) glycoprotein, and plasma concentrations of Lp(a) in three ethnic groups. Evidence for no common “null” allele at the apo(a) locus. J. Clin. Invest. 1994; 93: 2526-2534Google Scholar). Furthermore, Lpa levels vary across ethnicity, with the most profound differences between populations of African descent and non-African populations, including Asians and Caucasians (10Guyton J.R. Dahlen G.H. Patsch W. Kautz J.A. Gotto Jr., A.M. Relationship of plasma lipoprotein Lp(a) levels to race and to apolipoprotein B. Arteriosclerosis. 1985; 5: 265-272Google Scholar, 11Parra H.J. Luyeye I. Bouramoue C. Demarquilly C. Fruchart J.C. Black-white differences in serum Lp(a) lipoprotein levels. Clin. Chim. Acta. 1987; 168: 27-31Google Scholar, 12Gaubatz J.W. Ghanem K.I. Guevara Jr., J. Nava M.L. Patsch W. Morrisett J.D. Polymorphic forms of human apolipoproteina: inheritance and relationship of their molecular weights to plasma levels of lipoprotein a. J. Lipid Res. 1990; 31: 603-613Google Scholar, 13Sandholzer C. Hallman D.M. Saha N. Sigurdsson G. Lackner C. Csaszar A. Boerwinkle E. Utermann G. Effects of the apolipoprotein(a) size polymorphism on the lipoprotein(a) concentration in 7 ethnic groups. Hum. Genet. 1991; 86: 607-614Google Scholar, 14Marcovina S.M. Albers J.J. Jacobs Jr., D.R. Perkins L.L. Lewis C.E. Howard B.V. Savage P. Lipoproteina concentrations and apolipoproteina phenotypes in Caucasians and African Americans. The CARDIA study. Arterioscler. Thromb. 1993; 13: 1037-1045Google Scholar). This difference is not explained by a difference in apoa size frequency. Importantly, Africans as well as African Americans have substantially higher Lpa levels than do Caucasians or Asians, adjusting for apoa sizes (15Berglund L. Ramakrishnan R. Lipoprotein(a): an elusive cardiovascular risk factor. Arterioscler. Thromb. Vasc. Biol. 2004; 24: 2219-2226Crossref PubMed Scopus (196) Google Scholar, 16Marcovina S.M. Albers J.J. Wijsman E. Zhang Z. Chapman N.H. Kennedy H. Differences in Lpa concentrations and apoa polymorphs between black and white Americans. J. Lipid Res. 1996; 37: 2569-2585Google Scholar). Recently, we demonstrated that for small apoa sizes, differences in allele-specific apoa levels between African Americans and Caucasians were explained by allelic interactions and by an upstream pentanucleotide repeat polymorphism (17Rubin J. Kim H.J. Pearson T.A. Holleran S. Ramakrishnan R. Berglund L. Apoa size and PNR explain African American-Caucasian differences in allele-specific apoa levels for small but not large apo a. J. Lipid Res. 2006; 47: 982-989Google Scholar). However, differences in allele-specific apoa levels remain unexplained for larger apoa sizes. Overall, genetic factors have a major impact on Lpa levels (15Berglund L. Ramakrishnan R. Lipoprotein(a): an elusive cardiovascular risk factor. Arterioscler. Thromb. Vasc. Biol. 2004; 24: 2219-2226Crossref PubMed Scopus (196) Google Scholar, 18Geethanjali F.S. Luthra K. Lingenhel A. Kanagasaba-Pathy A.S. Jacob J. Srivastava L.M. Vasisht S. Kraft H.G. Utermann G. Analysis of the apo(a) size polymorphism in Asian Indian populations: association with Lp(a) concentration and coronary heart disease. Atherosclerosis. 2003; 169: 121-130Google Scholar, 19Ogorelkova M. Kraft H.G. Ehnholm C. Utermann G. Single nucleotide polymorphisms in exons of the apo(a) kringles IV types 6 to 10 domain affect Lp(a) plasma concentrations and have different patterns in Africans and Caucasians. Hum. Mol. Genet. 2001; 10: 815-824Google Scholar). Furthermore, as described above, we and others have identified several genetic variations that affect allele-specific apoa levels (8Kraft H.G. Lingenhel A. Pang R.W. Delport R. Trommsdorff M. Vermaak H. Janus E.D. Utermann G. Frequency distributions of apolipoprotein(a) kringle IV repeat alleles and their effects on lipoprotein(a) levels in Caucasian, Asian, and African populations: the distribution of null alleles is non-random. Eur. J. Hum. Genet. 1996; 4: 74-87Google Scholar, 16Marcovina S.M. Albers J.J. Wijsman E. Zhang Z. Chapman N.H. Kennedy H. Differences in Lpa concentrations and apoa polymorphs between black and white Americans. J. Lipid Res. 1996; 37: 2569-2585Google Scholar, 17Rubin J. Kim H.J. Pearson T.A. Holleran S. Ramakrishnan R. Berglund L. Apoa size and PNR explain African American-Caucasian differences in allele-specific apoa levels for small but not large apo a. J. Lipid Res. 2006; 47: 982-989Google Scholar, 20Chretien J.P. Coresh J Berthier-Schaad Y. Kao W.H. Fink N. Klag M.J. Marcovina S.M. Giaculli F. Smith M.W. Three single-nucleotide polymorphisms in LPA account for the majority of lipoprotein(a) level elevation in African Americans compared to European Americans. J. Med. Genet. 2006; 43: 917-923Google Scholar). Genetic variability of apolipoprotein E (apoE) is a major determinant of plasma lipoprotein levels (21Mahley R.W. Rall Jr., S.C. Apolipoprotein E: far more than a lipid transport protein. Annu. Rev. Genomics Hum. Genet. 2000; 1: 507-537Crossref PubMed Scopus (1311) Google Scholar), and furthermore, apoE genotype frequencies differ between African Americans and Caucasians (22Moore R.J. R.M. Apolipoprotein E and the risk of in and white A 2004; Scholar, P. of in a Scholar). As the African American-Caucasian differences in allele-specific apoa levels for large apoa sizes remain we on apoE as a genetic factor to have investigated the impact of apoE genotypes on Lpa levels, but the have no impact of apoE genotypes on Lpa levels were in several Saha N. of association of apolipoprotein E polymorphism with plasma Lp(a) levels in the Clin. Genet. Scholar, M. H. H. E. G. Lipoprotein(a) is an independent risk factor for at a Clin. Chem. 1990; Scholar, J. Ehnholm C. J. Dahlen G. Apolipoprotein E phenotypes in a and study. J. Lipid Res. 1990; 31: Scholar, S. R. C. J. F. J. Lipoprotein(a) in with risk factors and of Clin. Chem. Scholar, M. C. Apolipoprotein E polymorphism on and Lp(a) in a apo Atherosclerosis. 1996; Scholar, E. K. G. C. W. The effects of and apolipoprotein E polymorphism on serum and and lipoprotein(a). J. 1993; Scholar, S. S. Effects of and on the association of apolipoprotein E with plasma lipoprotein levels. the Arterioscler. Thromb. 1994; Scholar), others significant differences in plasma Lpa levels across apoE phenotypes P. A. L.M. Apolipoprotein E polymorphism plasma levels of lipoprotein(a). Atherosclerosis. 1991; 90: Scholar, L. C. Effects of apoE gene polymorphism on Lp(a) concentrations on the size of a of white J. Mol. Med. 1996; Scholar, P. R. J. J. Ehnholm C. Effects of and apolipoprotein E on serum lipoprotein(a) concentrations of J. Clin. 1996; Scholar, K. M. M. H. Y. H. M. A. A. I. Effects of apolipoprotein E polymorphism on plasma lipoprotein(a) levels. 1993; Scholar, R. B. P. A. and between and and apolipoprotein E J. Lipid Res. 2000; Scholar, G. F. S. M. Apolipoprotein E and lipoprotein(a) in for lipoprotein(a) Clin. 1994; Scholar). Among the P. A. L.M. Apolipoprotein E polymorphism plasma levels of lipoprotein(a). Atherosclerosis. 1991; 90: high plasma levels of Lpa and in Caucasians with the apo ε4 and the that Lpa is by the G. F. S. M. Apolipoprotein E and lipoprotein(a) in for lipoprotein(a) Clin. 1994; a similar of the apoE genotype on Lpa levels in with with E2 and E4 plasma Lpa levels. However, most of plasma Lpa levels, and levels are by apoa size we allele-specific apoa levels to the effects of the apoE gene on We that African apo ε2 compared with ε3 or ε4 had lower allele-specific apoa levels for large apoa sizes. were a for coronary at in or the in The has described (17Rubin J. Kim H.J. Pearson T.A. Holleran S. Ramakrishnan R. Berglund L. Apoa size and PNR explain African American-Caucasian differences in allele-specific apoa levels for small but not large apo a. J. Lipid Res. 2006; 47: 982-989Google Scholar, F. Pearson T.A. M. J. levels of Lp(a) with a small apo(a) are associated with coronary disease in African and white Arterioscler. Thromb. Vasc. Biol. 2000; Scholar, E. J. G. Pearson T.A. Holleran S. Ramakrishnan R. Berglund L. of apolipoprotein E2 on coronary disease in African Americans is through lipoprotein J. Lipid Res. 2006; 47: Scholar). a of were and of which were as Caucasians and were as African Americans. This is on the African Americans and 336 in Lpa levels and apoE genotypes were Apoa allele sizes, apoa and allele-specific apoa levels were for African Americans and This was by the at the the of and and the of and was were the and serum and plasma were at and and were determined levels were with the of and of the concentration of lipoprotein in of the Clin. Chem. Scholar). Lpa levels were in by a F. Pearson T.A. M. J. levels of Lp(a) with a small apo(a) are associated with coronary disease in African and white Arterioscler. Thromb. Vasc. Biol. 2000; Scholar, E. J. G. Pearson T.A. Holleran S. Ramakrishnan R. Berglund L. of apolipoprotein E2 on coronary disease in African Americans is through lipoprotein J. Lipid Res. 2006; 47: Scholar). apoa allele sizes, we of in as described C. Cohen J.C. Hobbs H.H. of the size polymorphism in Hum. Mol. Genet. 1993; PubMed Scopus Google Scholar, J. F. Holleran S. Pearson T.A. Ramakrishnan R. Berglund L. Apolipoprotein a genotype influences in African Americans and Caucasians. J. Lipid Res. 43: Scholar). Apoa sizes were by of plasma by the apoa were with the a F. Pearson T.A. M. J. levels of Lp(a) with a small apo(a) are associated with coronary disease in African and white Arterioscler. Thromb. Vasc. Biol. 2000; Scholar, polymorphism of apolipoprotein J. Hum. Genet. 1991; Scholar, S.M. Hobbs H.H. Albers J.J. between number of apolipoprotein(a) kringle 4 repeats and of in for a Clin. Chem. 1996; Scholar). The was determined by analysis of the apoa on the and the were by For apoa levels were to the of of the on the J. F. Holleran S. Pearson T.A. Ramakrishnan R. Berglund L. Apolipoprotein a genotype influences in African Americans and Caucasians. J. Lipid Res. 43: Scholar). were determined at the level by the and as described by and J.E. of human apolipoprotein E by gene and with J. Lipid Res. 1990; 31: Full Text PDF PubMed Google Scholar). Analysis of was with analysis are expressed as levels were and Lpa levels and allele-specific apoa levels were square to were compared between analysis and were compared The distribution of apoa alleles for apoE genotype was the for ethnic were for lipid and apolipoprotein levels for and were by for independent was for apoE distribution and were by for independent a P < was to Lipid and lipoprotein are in African Americans had significantly higher levels of and and lower levels of compared with Caucasians. There was no difference in the levels of and as well as in the levels of between the ethnic of the Americans = = < < < < < lipoprotein a. are were compared for ethnic were for lipid and apolipoprotein levels for and were by for independent for were and for Lpa were square P < P < in a lipoprotein a. are were compared for ethnic were for lipid and apolipoprotein levels for and were by for independent for were and for Lpa were square African Americans had a significantly higher of the ε2 vs. = P = and ε4 alleles vs. = P < and a significantly lower of the ε3 allele vs. = P < compared with Caucasians In a were three genotype ε2 carriers and ε3 carriers and ε4 carriers and We the of apoE gene variability on plasma Lpa levels in ethnic As in among African Americans, there was a in Lpa levels ε2 to ε3 to ε4 African ε2 carriers had significantly lower levels of Lpa compared with ε4 carriers (9.6 vs. 11.2 nmol/l; P = 0.034, expressed as square root levels). However, there were no differences in Lpa levels across apoE genotypes among Caucasians, and the levels were similar across apoE We that different of Lpa levels in African Americans across apoE genotypes to a different distribution of apoa alleles or a difference in allele-specific apoa levels. the we compared the distribution of apoa alleles for apoE genotype the As in there were no significant differences in distribution of apoa alleles in African Americans and Caucasians across apoE distribution of apolipoprotein a (apoa) allele size in African Americans and Caucasians across apoE The differences between apo and E4 genotypes in the distribution of apoa alleles were and in African Americans and and in Caucasians, which were not significantly different kringle As we not difference in apoa allele distribution across apoE we compared the distribution of allele-specific apoa levels. In with the Lpa levels among African Americans compared with Caucasians, the allele-specific apoa level was significantly higher in African Americans than in Caucasians vs. nmol/l; P < expressed as square root levels). apoa size we smaller larger apoa sizes the apoa size as in (17Rubin J. Kim H.J. Pearson T.A. Holleran S. Ramakrishnan R. Berglund L. Apoa size and PNR explain African American-Caucasian differences in allele-specific apoa levels for small but not large apo a. J. Lipid Res. 2006; 47: 982-989Google Scholar). As in allele-specific apoa levels for smaller apoa were similar across apoE genotypes among African Americans and Caucasians. However, for African Americans with larger apoa, the allele-specific apoa level was significantly lower in with the apo ε2 genotype compared with apo ε3 and ε4 carriers < and P < For I. difference was observed for Caucasians, larger allele-specific apoa levels were significantly lower compared with African Americans across apoE groups. Furthermore, we and differences in allele-specific apoa levels for large apoa sizes across apoE and levels in and were similar As described above, we an apoa size of in as the However, as a of has to small apoa, we analysis to large small The were the allele-specific large apoa levels in African ε2 and ε4 carriers were significantly different vs. nmol/l, respectively; P < expressed as square root difference was observed among Caucasians. The in are as African apo ε2 compared with ε3 or ε4 had lower allele-specific apoa levels for large apoa and apoE genotype contributed to the observed African American-Caucasian differences for large apoa sizes. We on the association of apoE genotypes and lipid levels in E. J. G. Pearson T.A. Holleran S. Ramakrishnan R. Berglund L. of apolipoprotein E2 on coronary disease in African Americans is through lipoprotein J. Lipid Res. 2006; 47: Scholar). This was to a impact of apoE genotypes on allele-specific apoa levels. have the apoE genotypes have a impact on plasma lipoprotein levels (21Mahley R.W. Rall Jr., S.C. Apolipoprotein E: far more than a lipid transport protein. Annu. Rev. Genomics Hum. Genet. 2000; 1: 507-537Crossref PubMed Scopus (1311) Google Scholar, E. J. G. Pearson T.A. Holleran S. Ramakrishnan R. Berglund L. of apolipoprotein E2 on coronary disease in African Americans is through lipoprotein J. Lipid Res. 2006; 47: apoE allele between African Americans and Caucasians (22Moore R.J. R.M. Apolipoprotein E and the risk of in and white A 2004; Scholar, P. of in a Scholar, E. J. G. Pearson T.A. Holleran S. Ramakrishnan R. Berglund L. of apolipoprotein E2 on coronary disease in African Americans is through lipoprotein J. Lipid Res. 2006; 47: plasma Lpa levels differ between African Americans and Caucasians (10Guyton J.R. Dahlen G.H. Patsch W. Kautz J.A. Gotto Jr., A.M. Relationship of plasma lipoprotein Lp(a) levels to race and to apolipoprotein B. Arteriosclerosis. 1985; 5: 265-272Google Scholar, 11Parra H.J. Luyeye I. Bouramoue C. Demarquilly C. Fruchart J.C. Black-white differences in serum Lp(a) lipoprotein levels. Clin. Chim. Acta. 1987; 168: 27-31Google Scholar, 12Gaubatz J.W. Ghanem K.I. Guevara Jr., J. Nava M.L. Patsch W. Morrisett J.D. Polymorphic forms of human apolipoproteina: inheritance and relationship of their molecular weights to plasma levels of lipoprotein a. J. Lipid Res. 1990; 31: 603-613Google Scholar, 13Sandholzer C. Hallman D.M. Saha N. Sigurdsson G. Lackner C. Csaszar A. Boerwinkle E. Utermann G. Effects of the apolipoprotein(a) size polymorphism on the lipoprotein(a) concentration in 7 ethnic groups. Hum. Genet. 1991; 86: 607-614Google Scholar, 14Marcovina S.M. Albers J.J. Jacobs Jr., D.R. Perkins L.L. Lewis C.E. Howard B.V. Savage P. Lipoproteina concentrations and apolipoproteina phenotypes in Caucasians and African Americans. The CARDIA study. Arterioscler. Thromb. 1993; 13: 1037-1045Google and the difference in allele-specific apoa levels for larger apoa size between African Americans and Caucasians is unexplained (17Rubin J. Kim H.J. Pearson T.A. Holleran S. Ramakrishnan R. Berglund L. Apoa size and PNR explain African American-Caucasian differences in allele-specific apoa levels for small but not large apo a. J. Lipid Res. 2006; 47: 982-989Google Scholar). In we have that African Americans have higher allele-specific apoa levels compared with Caucasians. Furthermore, we that apoE genotypes Lpa levels in African Americans but not in African with the apo E2 genotype had lower Lpa levels compared with apo ε3 or ε4 the of apoE gene variation on Lpa levels have the for differences have not Saha N. of association of apolipoprotein E polymorphism with plasma Lp(a) levels in the Clin. Genet. Scholar, M. H. H. E. G. Lipoprotein(a) is an independent risk factor for at a Clin. Chem. 1990; Scholar, J. Ehnholm C. J. Dahlen G. Apolipoprotein E phenotypes in a and study. J. Lipid Res. 1990; 31: Scholar, S. R. C. J. F. J. Lipoprotein(a) in with risk factors and of Clin. Chem. Scholar, M. C. Apolipoprotein E polymorphism on and Lp(a) in a apo Atherosclerosis. 1996; Scholar, E. K. G. C. W. The effects of and apolipoprotein E polymorphism on serum and and lipoprotein(a). J. 1993; Scholar, S. S. Effects of and on the association of apolipoprotein E with plasma lipoprotein levels. the Arterioscler. Thromb. 1994; Scholar, P. A. L.M. Apolipoprotein E polymorphism plasma levels of lipoprotein(a). Atherosclerosis. 1991; 90: Scholar, L. C. Effects of apoE gene polymorphism on Lp(a) concentrations on the size of a of white J. Mol. Med. 1996; Scholar, P. R. J. J. Ehnholm C. Effects of and apolipoprotein E on serum lipoprotein(a) concentrations of J. Clin. 1996; Scholar, K. M. M. H. Y. H. M. A. A. I. Effects of apolipoprotein E polymorphism on plasma lipoprotein(a) levels. 1993; Scholar, R. B. P. A. and between and and apolipoprotein E J. Lipid Res. 2000; Scholar, G. F. S. M. Apolipoprotein E and lipoprotein(a) in for lipoprotein(a) Clin. 1994; Scholar). of have in Caucasians, and furthermore, Lpa levels have As the apoa gene is highly the plasma Lpa level is a of different apoa size with allele-specific levels. to apoa size we allele-specific apoa levels to differences in the impact of apoE gene variation on Lpa in more L. C. Effects of apoE gene polymorphism on Lp(a) concentrations on the size of a of white J. Mol. Med. 1996; that the of apoE gene polymorphism on Lpa levels was on the molecular size of In their to and on plasma Lpa levels, determined apoa as molecular size and that for large apoa Lpa levels were high in and genotypes and in The that to a high of large apoa, as well as apo ε4 for which and by L. C. Effects of apoE gene polymorphism on Lp(a) concentrations on the size of a of white J. Mol. Med. 1996; Scholar, W. A. H. R. I. W. W. lipoprotein size differ by their with the lipoprotein and the lipoprotein 1993; Scholar). we not differences across apoE genotypes in Caucasians, for African Americans were in the with lower allele-specific apoa levels for apo ε2 For of we apoa levels as large or that we determined allele-specific apoa levels the of apoa sizes. we not of apoE genotypes on levels in the African effects of apoE on plasma E. J. G. Pearson T.A. Holleran S. Ramakrishnan R. Berglund L. of apolipoprotein E2 on coronary disease in African Americans is through lipoprotein J. Lipid Res. 2006; 47: Scholar). Overall, Lpa levels in African apo ε2 carriers at different the a different distribution of apoa alleles across apoE apo ε2 carriers have larger apoa sizes, more associated with lower Lpa levels. the to a difference in allele-specific apoa levels across apoE the we not differences in the of apoa alleles in across apoE genotypes We analysis to allele-specific apoa levels and their distribution across apoE allele-specific apoa levels a different across apoE carriers among African Americans but not among Caucasians. we that African Americans with larger apoa size had significant differences in allele-specific apoa levels across apoE allele-specific levels were lower among ε2 carriers compared with apo ε3 and ε4 In contrast, no difference was for small apoa sizes. the for the of apoE variation on apoa levels in African Americans to several the of a at the a as the apoa and apoE are on different and for in and However, is well that the apoE gene in the of apoE the of and a and the of and to the (21Mahley R.W. Rall Jr., S.C. Apolipoprotein E: far more than a lipid transport protein. Annu. Rev. Genomics Hum. Genet. 2000; 1: 507-537Crossref PubMed Scopus (1311) Google Scholar). in the ε4 allele has associated with levels of and the ε2 allele has associated with lower and concentrations. Furthermore, an of apoE on lipoprotein has demonstrated B. M. R.J. Effects of E on of are effects on J. Biol. Chem. Scholar, H. M.J. R. L.M. Apolipoprotein E in the of by the J. Biol. Chem. Scholar). As Lpa levels are by to an between apoE and apoa on the However, are to an of to in were for coronary and for the number was As the apo E4 genotype has associated with cardiovascular a of a distribution of apoE genotypes in compared with the at the apoE allele was similar to that described for African and populations (22Moore R.J. R.M. Apolipoprotein E and the risk of in and white A 2004; Scholar, P. of in a Scholar). Furthermore, the apo ε4 allele was similar in with and coronary disease for African Americans vs. and Caucasians vs. In that allele-specific levels are lower among African ε2 for large apoa sizes, no differences were observed among Caucasians. to in African and are to This was by and the and This was in by the of with
Anuurad et al. (Sat,) studied this question.