title: Variation in LPA is associated with Lp(a) levels in three populations from the Third National Health and Nutrition Examination Survey.
abstract: The distribution of lipoprotein(a) [Lp(a)] levels can differ dramatically across diverse racial/ethnic populations. The extent to which genetic variation in LPA can explain these differences is not fully understood. To explore this, 19 LPA tagSNPs were genotyped in 7,159 participants from the Third National Health and Nutrition Examination Survey (NHANES III). NHANES III is a diverse population-based survey with DNA samples linked to hundreds of quantitative traits, including serum Lp(a). Tests of association between LPA variants and transformed Lp(a) levels were performed across the three different NHANES subpopulations (non-Hispanic whites, non-Hispanic blacks, and Mexican Americans). At a significance threshold of p<0.0001, 15 of the 19 SNPs tested were strongly associated with Lp(a) levels in at least one subpopulation, six in at least two subpopulations, and none in all three subpopulations. In non-Hispanic whites, three variants were associated with Lp(a) levels, including previously known rs6919246 (p = 1.18 × 10(-30)). Additionally, 12 and 6 variants had significant associations in non-Hispanic blacks and Mexican Americans, respectively. The additive effects of these associated alleles explained up to 11% of the variance observed for Lp(a) levels in the different racial/ethnic populations. The findings reported here replicate previous candidate gene and genome-wide association studies for Lp(a) levels in European-descent populations and extend these findings to other populations. While we demonstrate that LPA is an important contributor to Lp(a) levels regardless of race/ethnicity, the lack of generalization of associations across all subpopulations suggests that specific LPA variants may be contributing to the observed Lp(a) between-population variance.
authors.affiliation: Center for Human Genetics Research, Vanderbilt University, Nashville, Tennessee, United States of America.
authors.forename: Logan
authors.initials: L
authors.lastname: Dumitrescu
authors.forename: Kimberly
authors.initials: K
authors.lastname: Glenn
authors.forename: Kristin
authors.initials: K
authors.lastname: Brown-Gentry
authors.forename: Cynthia
authors.initials: C
authors.lastname: Shephard
authors.forename: Michelle
authors.initials: M
authors.lastname: Wong
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Rieder
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Smith
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Nickerson
authors.forename: Dana C
authors.initials: DC
authors.lastname: Crawford
mesh_terms: D044383:Black People / Q000235:genetics; D014644:Genetic Variation; D005838:Genotype; D006630:Hispanic or Latino / Q000235:genetics; D006801:Humans; D017270:Lipoprotein(a) / Q000097:blood* / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D044382:Population Groups / Q000235:genetics*; D044465:White People / Q000235:genetics
chemical_list: D017270:Lipoprotein(a)