TaqI B1/B2 and -629A/C cholesteryl ester transfer protein (CETP) gene polymorphisms and their association with CETP activity and high-density lipoprotein cholesterol levels in a Tehranian population. Part of the Tehran Lipid and Glucose Study (TLGS)

Genetic Identification for Non-Communicable Disease: Findings from 20 Years of the Tehran Lipid and Glucose Study

CONTEXT

Tehran Lipid and Glucose Study (TLGS), a longitudinal family based cohort study, is the oldest and largest longitudinal family based study in Iran, aimed at investigating effects of environmental, social and biological factors on the health of Tehranians over time. Considering the importance of genetic studies in this aspect, here we present a summary of the important genetic findings, and the potentiality of their contributions to future related projects.

EVIDENCE ACQUISITION

For all related studies during the past 20 years the search sources were all prominent search engines such as PubMed, Scopus, and Google Scholar with the most proper Medical Subject Headings (MeSH).

RESULTS

This review summarizes associations of 6 binary phenotypes and 17 quantitative traits with genetic markers in 26 genes. Of the 47 genetic markers, studied most were related to cardio metabolic risk factors. Results of heritability and linkage analysis were also collected and the highest heritability was found to be related to HDL-C (0.5).

CONCLUSION

Considering the opportunity provided by large-scale cohort studies to investigate molecular effects of genetic variants on causality and different omics' data, genetic studies conducted on TLGS population have had a remarkable success in identifying genetic variants that facilitating a unique genetic database on Iranian populations. The results of genome wide association studies in this population are currently facilitating investigations to define the Iranian genetic differences with other population.

Association between CETP Taq1B and LIPC -514C/T polymorphisms with the serum lipid levels in a group of Tehran's population: a cross sectional study

BACKGROUND

Low level of high density lipoprotein cholesterol (HDL-C) has high prevalence in the Tehran Lipid and Glucose Study (TLGS) cohort. About 50% of the inter-individual variation in serum HDL-C levels is genetically determined. Polymorphisms in cholesteryl ester transfer protein (CETP) and hepatic lipase (LIPC) genes have been found to be associated with the metabolism and serum concentration of the HDL-C.

OBJECTIVES

To determine the association between Taq1B polymorphism in CETP gene and -514C/T polymorphism in LIPC gene with serum lipid levels and lipid peroxidation in a subgroup of the TLGS population.

RESULTS

Serum HDL-C level had significant association with CETP Taq1B polymorphism and B2B2 subjects had the highest HDL-C levels compared to B2B1 and B1B1 genotypes (37.9 vs. 36.9 and 35.3 mg/dl, respectively; P = 0.01). However, carriers of "B1" allele, in comparison to the non carriers (B2B2), had significantly lower levels of TC (200.1 vs. 215.2 mg/dl; P = 0.005), HDL-C (35.8 vs. 37.9 mg/dl; P = 0.009) and malondialdehyde MDA (4.5 vs. 5.0 nmol/mL; P=0.031). Carriers of the "T" allele in -514C/T polymorphism in LIPC gene had higher means of HDL-C than non carriers (37.7 vs. 35.7 mg/dl, P = 0.04). No other association was found between -514C/T polymorphism and any other serum lipids or MDA level.

CONCLUSION

This study demonstrates the association between Taq1B and -514C/T polymorphisms in the CETP and LIPC genes with the serum HDL-C levels.