Lack of genetic linkage evidence for a trans-acting factor having a large effect on plasma lipoprotein[a] levels in African Americans.
The distribution of plasma lipoprotein[a] (Lp[a]) concentrations, a risk factor for cardiovascular disease, varies greatly among racial groups, with African Americans having values that are shifted toward higher levels than those of whites. The underlying cause of this heterogeneity is unknown, but a role for "trans-acting" factors has been hypothesized. This study used genetic linkage analysis to localize genetic factors influencing Lp[a] levels in African Americans that were absent in other populations; linkage results were analyzed separately in non-Hispanic whites, Hispanic whites, and African Americans. As expected, all three samples showed highly significant linkage at the approximate location of the lysophosphatidic acid locus. The white populations also independently had regions of significant linkage on chromosome 19 (LOD 3.80) and suggestive linkage on chromosomes 12 (LOD 1.60), 14 (LOD 2.56), and 19 (LOD 2.52). No linkage evidence was found to support the hypothesis of another single gene with large effects specifically segregating in African Americans that may account for their elevated Lp[a] levels.
Human Genetics Center and Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
Ruth Ann
RA
Barkley
Andrew C
AC
Brown
Craig L
CL
Hanis
Sharon L
SL
Kardia
Stephen T
ST
Turner
Eric
E
Boerwinkle
D000328:Adult; D001741:Black or African American; D000368:Aged; D044383:Black People; D002881:Chromosomes, Human, Pair 12; D002883:Chromosomes, Human, Pair 14; D002888:Chromosomes, Human, Pair 19; D008040:Genetic Linkage; D006801:Humans; D017270:Lipoprotein(a) / Q000097:blood*; D008126:Lod Score; D008246:Lysophospholipids / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D015533:Transcriptional Activation; D044465:White People
D017270:Lipoprotein(a); D008246:Lysophospholipids