Genetic studies of human apolipoproteins. XX. Genetic polymorphism of apolipoprotein J and its impact on quantitative lipid traits in normolipidemic subjects.
Apolipoprotein J (apo J) is a newly identified member of a growing family of proteins associated with various lipoprotein particles. Apo J is a glycoprotein which exists in the plasma associated with high-density lipoprotein subfractions which also contain apo A-I and cholesteryl ester transfer protein (CETP). We have investigated the possible existence of genetic polymorphism at the apo J structural locus and have evaluated its role in lipid metabolism. By employing isoelectric focusing and immunoblotting techniques, we have screened plasma or serum samples from six population groups: U.S. whites, Amerindians, Eskimos, New Guineans, U.S. blacks, and Nigerian blacks. Apo J revealed a common two-allele polymorphism only in populations with African ancestry and was found to be monomorphic in all other population groups tested. The genetic basis of the two alleles designated--APO J*1 and APO J*2, at a single structural locus, apo J-- was confirmed in a large number of segregating families. In the U.S. blacks, the frequencies of the APO J*1 and APO J*2 alleles were .76 and .24, respectively, and in the Nigerian blacks these values were .72 and .28, respectively. In addition, a single example of a rare allele designated APO J*3 was also encountered in the U.S. black sample. In Nigerian blacks, the apo J polymorphism's impact on seven quantitative lipid traits--total cholesterol, LDL-cholesterol, HDL-cholesterol, HDL3-cholesterol, HDL2-cholesterol, VLDL-cholesterol, and triglycerides--was investigated. No significant impact of the apo J polymorphism was observed for any of these lipid traits.
Kamboh
M I
MI
Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, PA 15261.
Harmony
J A
JA
Sepehrnia
B
B
Nwankwo
M
M
Ferrell
R E
RE
D000293:Adolescent; D000328:Adult; D001053:Apolipoproteins / Q000097:blood / Q000235:genetics*; D044383:Black People / Q000235:genetics; D051152:Clusterin; D005260:Female; D006023:Glycoproteins; D006801:Humans; D007525:Isoelectric Focusing; D008055:Lipids / Q000097:blood* / Q000235:genetics; D008075:Lipoproteins, HDL / Q000097:blood / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D018832:Molecular Chaperones; D009549:Nigeria / Q000208:ethnology; D011110:Polymorphism, Genetic; D044465:White People / Q000235:genetics
D001053:Apolipoproteins; C495242:CLU protein, human; D051152:Clusterin; D006023:Glycoproteins; D008055:Lipids; D008075:Lipoproteins, HDL; D018832:Molecular Chaperones