Identification of Two Common Variants Contributing to Serum Apolipoprotein B Levels in Mexicans

Background and Purpose— Although the Mexican population has a high predisposition to dyslipidemias and premature coronary artery disease, this population is underinvestigated for the genetic factors conferring the high susceptibility. This study attempted to determine these genetic factors. Methods and Results— First, we investigated apolipoprotein B (apoB) levels in Mexican extended families with familial combined hyperlipidemia using a two-step testing strategy. In the screening step, we screened 5721 single-nucleotide polymorphisms (SNPs) for linkage signals with apoB. In the test step, we analyzed the 130 SNPs residing in regions of suggestive linkage signals for association with apoB. We identified significant associations with two SNPs (ie, rs1424032 [P=6.07×10−6] and rs1349411 [P=2.72×10−4]) that surpassed the significance level for the number of tests performed in the test step (P<3.84×10−4). Second, these SNPs were tested for replication in Mexican hyperlipidemic case-control samples. The same ri...