Five restriction fragment length polymorphisms of the APOA1-C3 gene and their influence on lipids and apolipoproteins in healthy Chinese

Effects of apolipoprotein A-I genetic variations on plasma apolipoprotein, serum lipoprotein and glucose levels

The present authors investigated the individual and combined associations of the apolipoprotein (apo) A-I -75 bp and +83 bp polymorphisms with plasma lipid, lipoprotein and apolipoprotein levels in 734 Caucasian men and women. The frequency of the A allele at position -75 bp (G-->A) was 0.14 in women and 0.17 in men. The frequencies for the rare M2 allele at position +83 bp and/or 84 bp (C-->T and G-->A, respectively) were 0.04 and 0.05 in women and men, respectively. In women, the A allele was associated with significantly higher levels of apo B (P = 0.016), total cholesterol (TC) (P = 0.005), low-density lipoprotein cholesterol (LDL-C) (P = 0.018) and TC:high-density lipoprotein (HDL) ratio (P = 0.026) compared to the G/G subjects. In men, no significant associations were detected between the -75 bp polymorphism and any lipid trait examined. The M2 allele for the +83 bp polymorphism was significantly associated in men with higher levels of apo A-I (P = 0.002) and TC (P = 0.046). In women, a significant effect was observed for TC (P = 0.036), with M2+/- subjects having lower levels than M2+/+ subjects. Significant linkage disequilibrium (P = 0.037) between the apo A-I -75 bp and +83 bp polymorphisms was detected. Women carrying both rare alleles (G/A M2+/-) had significantly higher TC:HDL ratios (P = 0.031) compared to the other haplotypes. In men, significant differences were observed for apo A-I (P = 0.021) and TC (P = 0.044), with carriers of the G/G M2+/- haplotype having the highest values compared to other genotype combinations. In conclusion, the -75 bp (G/A) polymorphism appears to have a significant effect on levels of apo B, plasma TC and LDL-C in women, while the +83 bp polymorphism seems to affect the apo A-I levels in men, and the plasma cholesterol levels in both genders.

Apolipoprotein AI and CIII gene polymorphisms and their association with lipid levels in Italian, Greek and Anglo-Irish populations of Australia

PRIMARY OBJECTIVE

The apolipoprotein (apo) AI-CIII-AIV gene cluster on chromosome 11 has been identified as a candidate region for hyperlipidaemia and in particular for hypertriglyceridaemia. Our aim was to detect associations between the apo AI and CIII polymorphisms and the plasma lipids, total cholesterol, triglycerides, high density lipoprotein (HDL) and low density lipoprotein (LDL) cholesterol in normal, healthy, adults from three ethnic groups of Australia--Italian, Greek and Anglo-Irish, separately by gender.

METHODS AND PROCEDURES

The SstI restriction fragment length polymorphisms (RFLP) in the 3' untranslated region of the apo CIII gene and the MspI RFLP in the third intron of the apo AI gene were scored and the lipid concentrations were ascertained using standard methodologies. t-tests were used to compare lipid levels between sexes and between populations, and multivariate ANOVA was used to detect if the two RFLPs had an effect on any of the lipid concentrations.

MAIN OUTCOMES AND RESULTS

The two RFLPs exhibit strong linkage disequilibrium in all three populations (p < 0.001). There were some significant differences in allele frequencies among the populations: the minor S2 allele was more frequent in Italians (0.12) than Greeks (0.03) (p = 0.003), and the minor M2 allele was more common in Greeks (0.14) than Anglo-Irish (0.05) (p = 0.026). We found no significant association between either of the RFLPs and any of the lipid concentrations in either sex of all three populations. However, Kruskal-Wallis tests detected associations of borderline significance between apo AI MspI genotypes and triglycerides (p = 0.04) and between apo AI MspI genotypes and cholesterol levels (p = 0.03) in Anglo-Irish females.

CONCLUSIONS

Because only two statistically significant associations were detected among a number of comparisons, our data suggest that the apo AI and CIII polymorphisms play only a very limited role in mediating variation in lipid concentrations in these three ethnic groups.

Variations of cardiovascular disease associated genes exhibit sex-dependent influence on human longevity

This article investigates the relationship between the polymorphic variations in genes associated with cardiovascular disease and longevity in the Danish population. A new procedure that combines both demographic and the individual genetic information in determining the relative risks of the observed genetic variations is applied. The sex-dependent influences can be found by introducing sex-specific population survival and incorporating the risk of gene-sex interaction. Three genetic polymorphisms, angiotensinogen M/T235, blood coagulation factor VII (FVII) R/Q353 and FVII-323ins10, manifest significant influences on survival in males, with reduced hazards of death for carriers of the angiotensinogen M235 allele, the F VII Q353 allele, and the FVII-323P10 allele. The results show that some of these genotypes associated with lower risk of CVD could also reduce the carrier's death rate and contribute to longevity. However, the presence of sex-dependent effects and the fact that major CVD-associated genes failed to impose detrimental influence on longevity lead us to concur that the aging process is highly complicated.

Association of apolipoprotein genetic polymorphisms with plasma cholesterol in a Japanese rural population. The Shibata Study

The association between apolipoprotein (apo) genetic polymorphisms and lipid phenotypes remains to be determined because such studies have reported contradictory results. We have measured plasma total cholesterol (TC) and HDL cholesterol (HDL-C) in a cross-sectional sample of 1328 (462 men and 866 women) Japanese (aged 40 to 80 years) and analyzed their DNA for the following genotypes: apoA1-C3 Msp I and Sst I sites; apoB signal peptide insertion/deletion, Xba I site and 3' variable number of tandem repeats (VNTR); and apoE. Using multivariate analyses (ANOVA) we found that (1) the polymorphisms of apoA1-C3 and apoB genes are not significantly associated with TC or HDL-C and (2) the polymorphism of the apoE gene is significantly related with TC and the TC:HDL-C ratio. The epsilon 2 carriers have lower levels of TC and a lower TC:HDL-C ratio, epsilon 3 carriers have intermediate levels, and epsilon 4 carriers have higher levels. These findings held whether sexes were analyzed separately or together. Although an opposite trend in HDL-C levels was observed, it did not reach the level of statistical significance. Multiple regression analyses have shown that apoE polymorphism accounts for about 2.3% of the variation in TC and TC:HDL-C ratio irrespective of sex. When the subjects are divided into two groups according to their age (< or = 59 and > or = 60 years old), the effect of apoE alleles on serum cholesterols appears to be diluted in the younger age group whereas it appears to be accentuated in the older group for both sexes. Our findings suggest that among the apo genetic polymorphisms examined, the apoE gene may be considered as a possible candidate for the "high-risk" strategy of atherosclerosis prevention in the Japanese population.

Association between genetic variations of apo AI-CIII-AIV cluster gene and hypertriglyceridemic subjects

Several studies have suggested that genetic variations of the apolipoprotein (apo) AI-CIII-AIV cluster gene are associated with hyperlipidemia or atherosclerosis. These investigations were carried out mainly with Caucasian groups; there have been few associated studies involving non-Caucasian groups. This study was conducted to elucidate the association between five restriction fragment length polymorphisms (RFLPs) of the apo AI-CIII-AIV cluster gene and Korean hypertriglyceridemic subjects. The rare allele frequencies of the XmnI and SstI polymorphic sites in the patients were significantly higher than those of the control group (P &lt;0.05). These two polymorphic sites had relation to linkage disequilibrium in the hypertriglyceridemic subjects (Δ = −0.2733). In addition, S2 allele frequency of the SstI RFLP in Koreans was more frequent than that of Caucasians reported previously. The rare allele of XmnI and SstI polymorphic sites was associated with increased triglyceride concentrations in the hypertriglyceridemic group (P &lt;0.005). Koreans have a much lower prevalence of hyperlipidemia than Caucasians. Nevertheless, this study showed a similar trend with results from Caucasian groups, thereby confirming that genetic variations of the apo AI-CIII-AIV cluster gene are likely to be significant markers for hypertriglyceridemic sub-jects. Thus, RFLP loci of the apo AI-CIII-AIV cluster gene may be a useful genetic marker for clinical or population studies.