In the United States, coronary heart disease (CHD) is the most common cause of death and number one killer of American males and females. Several epidemiological studies have identified risk factors for CHD, like low high-density lipoprotein cholesterol (HDL-C), elevated total cholesterol and low-density lipoprotein (LDL) cholesterol, and high triglycerides (TGs), but underlying genetic variations that cause predisposition to these traits still remain unclear. Lipoprotein lipase (LPL) is one of the major genes involved in lipid metabolism and its gene sequence variation has already been reported to be associated with the risk of CHD and risk of other complex diseases like dyslipidemia, type 2 diabetes, essential hypertension, and Alzheimer's disease. Unraveling the unknown genetic variation in the LPL gene in relation to HDL-C and correlated lipid traits is critically important for public health because identification of genetic markers may lead to promising future public health interventions, like prognostic tools and therapeutic approaches to alleviate the burden of CHD in the U.S. In this study, we investigated the role of common and rare variation in LPL by resequencing individuals having extremely low (n=48) and high (n=47) HDL-C levels selected from a population-based non-Hispanic white (NHW) sample of 623 individuals. A total of 179 variants were identified in 95 individuals by resequencing the entire LPL gene, including 91 uncommon or rare variants [minor allele frequency (MAF) <0.05)] and 88 common variants (MAF ≥ 0.05). Of the 91 relatively uncommon or rare variants, 21 were present only in the low-HDL group and 25 were present only in the high HDL-C group. Overall, the prevalence of uncommon or rare variants was higher in the high HDL-C than the low HDL-C group. Thirty two of the 88 common variants demonstrated significant association (P-value <0.05) between the high and low HDL-C groups. We also examined 12 common variants (MAF ≥ 0.05) in the total NHW sample and identified 7 variants to be significantly associated with lipid levels. In conclusion, our comprehensive resequencing of the LPL gene confirms that both common and rare variants in this gene are associated with interindividual variation in plasma lipid profile
