APOA1/C3/A5 haplotype and risk of hypertriglyceridemia in Taiwanese

BACKGROUND: Apolipoprotein A5 gene (APOA5) has been shown to modulate plasma triglyceride concentrations. We investigated 2 distinct APOA1/C3/A5 haplotypes roles for hypertriglyceridemia. METHODS: We recruited 308 cases of hypertriglyceridemia and 281 normal controls from a hospital. Twelve single nucleotide polymorphisms (SNPs) across the APOA1/C3/A5 gene region were genotyped. RESULTS: One haplotype containing the minor alleles of the APOA5 (-1131T>C, c.553G>T) and APOA1 (-3013C>T,-75G>A) was more prevalent in cases than in controls (11.3% vs. 1.1%, respectively) and was statistically significantly associated with high triglycerides (adjusted odds ratio: 12.83, 95% confidence interval [CI]: 5.1-32.4, P<0.001). Another haplotype that was associated with hypertriglyceridemia (adjusted odds ratio 2.13, 95% CI, 1.37-3.29, P=0.001). Participants carrying both minor alleles of APOA5-1131CC and c.553TT had a 116% higher triglyceride concentration compared with those carrying common allele. CONCLUSIONS: The APOA1/C3/A5 haplotype represents an important locus for predicting risk of hypertriglyceridemia among Taiwanese.     

Gender-modulated impact of apolipoprotein A5 gene (APOA5) -1131T>C and c.56C>G polymorphisms on lipids, dyslipidemia and metabolic syndrome in Turkish adults

BACKGROUND: Apolipoprotein A5 (APOA5) gene polymorphisms are usually associated with plasma triglyceride levels. We evaluated the relationship of the APOA5 -1131T>C and c.56C>G polymorphisms [single nucleotide polymorphism (SNP)] with serum lipids, dyslipidemia [low high-density lipoprotein (HDL)/high triglyceride] and the risk for metabolic syndrome (MS) in the Turkish Adult Risk Factor study. METHODS: We genotyped SNPs using the Taqman allelic discrimination assays in 1564 Turkish adults (51.4% female, mean age 54.1+/-11.6 years). MS and dyslipidemia were defined using the criteria of the National Cholesterol Education Program. RESULTS: For both SNPs, rare allele carriers had significantly higher fasting triglyceride levels in both genders, except the c.56G allele in men. The -1131C allele was associated with lower HDL cholesterol (HDL-C) levels in women. In relation to dyslipidemia, the c.56C>G and haplotype 1 had significant gender-genotype interactions (p<0.05). Otherwise, both SNPs were significantly associated with dyslipidemia after adjustment for risk factors in women. After similar adjustment, non-carriers of the haplotype 1 (odds ratio=4.1, p=0.003) increased the MS risk in women. However, no significant associations emerged between SNPs and HDL-C, dyslipidemia or MS in a similar analysis in men. CONCLUSIONS: Excess risk for low HDL-C, dyslipidemia and MS is associated with the rare alleles of the APOA5 SNPs and non-carriers of common haplotype in women.     

APOA1 polymorphisms are associated with variations in serum triglyceride concentrations in hypercholesterolemic individuals.

BACKGROUND: Apolipoprotein A-I gene (APOA1) polymorphisms have been associated with variations in serum low-density lipoprotein (LDL)- and high-density lipoprotein (HDL)-cholesterol. We have investigated whether APOA1 common variants are also associated with variations in basal triglyceride serum concentrations and response to atorvastatin in individuals with hypercholesterolemia. METHODS: APOA1 G-75A and C83T polymorphisms and variations in serum lipids were evaluated in 150 hypercholesterolemic (HC) and 93 normolipidemic (NL) unrelated European-derived Brazilians treated with atorvastatin (10 mg/day for 4 weeks). Genomic DNA was extracted from blood leukocytes using a salting-out method and APOA1 polymorphisms were analyzed by polymerase chain reaction and restriction fragment length polymorphism. RESULTS: G-75A polymorphism was associated with differences in serum concentrations of triglyceride and very low-density lipoprotein (VLDL)-cholesterol (p=0.026) in HC men. After atorvastatin treatment, women carrying the GG/CC haplotype had lower serum triglyceride and VLDL-cholesterol (p=0.020) than non-carriers. In men, the reduction in serum triglyceride in response to atorvastatin was found to be slightly lower in GG/CC haplotype carriers (p=0.051). CONCLUSION: Our data suggest that APOA1 polymorphisms are associated with variations of baseline serum concentrations of triglyceride and VLDL-cholesterol and in response to atorvastatin in a gender-specific manner.     

Association between plasma lipid parameters and APOC3 genotypes in Brazilian subjects: effect of gender, smoking and APOE genotypes

BACKGROUND: APOC3 polymorphisms were associated with lipid parameters and coronary artery disease in several populations but not all. Considering the multifactorial inheritance and environmental factors that underlie the determination of triglyceride (TG) and HDL-C levels, the aims of the present study were to perform association analyses of APOC3 polymorphisms and these lipids in a southern Brazilian population of European descent to investigate possible interactions with other genetic and/or environmental factors. METHODS: Six hundred and seventy-three subjects participated in the study. -482C>T, -455T>C and 3238C>G polymorphisms genotyping were carried out by PCR followed by restriction enzyme digestion. RESULTS: In female subjects the APOC3-APOE genotype combinations had a significant effect on triglyceride levels (ANOVA, P=0.009). Post hoc analysis showed that the observed differences were between APOC3 S(*)2 carriers and S(*)1S(*)1 homozygotes in individuals with an APOE(*)3/3 genotype (Tukey HSD post hoc test, P=0.027). In APOE(*)3/(*)3 subjects, the raising effect of APOC3 S(*)2 allele on TG concentrations was more pronounced in female smokers (+59.4%) than in nonsmokers (+18.8%, P of S(*)2-smoking interaction=0.009). Among APOE(*)3/(*)3 subjects, male carriers of the less common alleles -482T and -455C had significant lower levels of HDL-C compared to homozygotes -482C/C and -455T/T (P=0.02 and P=0.006, respectively). CONCLUSION: APOC3 polymorphisms were associated with lipid variables, but the magnitude of these associations was modulated by additional genetic, biologic and/or environmental factors.     

The influence of the adiponectin gene on adiponectin concentrations and parameters of metabolic syndrome in non-diabetic Korean women

BACKGROUND: Concentrations of adiponectin, the protein product of the adipocyte C1q and collagen-domain-containing (ADIPOQ) gene are associated with type 2 diabetes and coronary artery disease. We investigate the association of single-nucleotide polymorphisms (SNPs) in the ADIPOQ gene with adiponectin concentrations, and to parameters of metabolic syndrome. METHODS: 867 unrelated, non-diabetic Korean women, 20 to 69 y, were genotyped for 8 SNPs in the ADIPOQ gene (-11391G>A, -11377C>G, H241P, Y111H, G90S, R221S, 45T>G, 276G>T). Adiponectin, a homeostasis model assessment of insulin resistance (HOMA-IR), and metabolic parameters were measured. RESULTS: Carriers of genotype T/T at position 276 had significantly higher adiponectin concentrations than G/G carriers (P=0.005). Homozygous carriers of the TG haplotype (i.e., individuals who were T/T at 45 and G/G at 276) and heterozygous carriers of the TG haplotype (TG/X) had lower adiponectin concentrations than non-TG carriers (P<0.001). Significant associations between SNP at 276 and serum concentrations of triglyceride (P=0.013), insulin (P=0.013) and HOMA-IR (P=0.012) were found. The 45-276 haplotypes had associations identical to the 276G>T SNP. In subgroup analysis, subjects carrying the TG haplotype had significantly lower adiponectin concentrations than non-TG carriers in both normal weight (P<0.001) and overweight-obese (P=0.009) subgroups. The association of the TG haplotype with increasing insulin concentrations was significant among overweight-obese subjects (P=0.004), but was not significant among normal weight subjects. A similar association was found between the 45-276 haplotype and HOMA-IR. CONCLUSION: There is a strong association of the adiponectin SNP276 genotypes and the adiponectin 45-276 haplotypes with circulating adiponectin concentrations in non-diabetic Korean women. In addition, this haplotype is associated with increased insulin concentrations and insulin resistance index only in overweight-obese individuals.     

Apolipoprotein A-V gene polymorphisms in subjects with metabolic syndrome.

BACKGROUND: Genetic variation at the apolipoprotein A-V locus, recently discovered proximal to the APOA1/C3/A4 gene cluster, is associated with elevated triglyceride concentrations, a risk factor for atherosclerosis. METHODS: The goal of our study was to determine the association of two apolipoprotein A-V (APOA5) gene polymorphisms in a group of urban Romanian subjects with the prevalence of the metabolic syndrome. For this purpose, we assayed -1.131T>C and c.56C>G polymorphisms for 279 subjects divided into three groups: a control group, a metabolic syndrome group and a cardiovascular disease group. Then we correlated the minor allele frequencies with body mass index and biochemical parameters. RESULTS: We obtained higher frequency for -1.131C compared to c.56G alleles, both mainly distributed in overweight subjects. Body mass index and triglyceride levels were higher in -1.131C allele carriers in metabolic syndrome patients, but were not significantly different in c.56G carriers compared to those with the native gene. Metabolic syndrome -1.131C homozygotes presented lower high-density lipoprotein cholesterol and higher glucose levels compared to subjects with the native gene. Total cholesterol, low-density lipoprotein cholesterol and insulin were not different between -1.131C or c.56G allele carriers and those with the native gene. CONCLUSIONS: Our results demonstrate an independent risk for -1.131T>C APOA5 gene polymorphisms in the development of metabolic syndrome.     

Association of APOA5 c.553G>T polymorphism with type 2 diabetes mellitus in a Chinese population.

BACKGROUND: Several independent population studies have reported that c.553G>T polymorphism of the apolipoprotein A5 gene (APOA5) is associated with hypertriglyceridaemia. The aim of this study is to investigate the association between this genetic variation and the risk of type 2 diabetes mellitus. METHODS: In this study, APOA5 c.553G>T polymorphisms in 152 healthy individuals and 71 type 2 diabetes mellitus patients were detected by PCR-restriction fragment length polymorphism and agarose electrophoresis methods, and serum levels of lipids were also estimated by biochemical methods. RESULTS: The frequency of T alleles in the diabetes and control groups was 0.085 and 0.049, respectively. Compared with controls, there was no significant difference in the distribution of genotype and allele frequencies of c.553G>T polymorphic sites in diabetic patients (p=0.27 and p=0.15, respectively). However, the frequency of GT and TT genotypes and the T allele in the subgroup with hypertriglyceridaemia was significantly higher than that in the subgroup with normal triglyceridaemia in both the control group (p=0.034 and p=0.014, respectively) and the diabetes group (p=0.037 and p=0.007, respectively). In the diabetes and control groups, triglyceride levels in (GT+TT) genotype individuals were significantly higher than in GG genotype individuals (p=0.001 and p=0.003, respectively), and levels of low-density lipoprotein cholesterol were also significantly higher (p=0.044 and p=0.022, respectively). CONCLUSIONS: APOA5 c.553G>T polymorphism is not significantly associated with susceptibility to type 2 diabetes mellitus, but is associated with plasma triglyceride and low-density lipoprotein cholesterol levels.     

The role of common variants of ABCB1, CYP3A4, and CYP3A5 genes in lipid-lowering efficacy and safety of simvastatin treatment

OBJECTIVE: Our objective was to investigate the interactions between common polymorphisms in ABCB1, CYP3A4, and CYP3A5 genes and the lipid-lowering efficacy and safety of the 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor simvastatin. METHODS: One hundred sixteen hypercholesterolemic patients were prospectively screened by physical examination, medical history, and clinical laboratory evaluation and were included in this study. Subjects entering the study were treated with 20 mg/d simvastatin. Plasma lipid and lipoprotein levels were measured before treatment, after 2 months of treatment, and after 6 months of treatment. Ninety-nine patients completed the 6-month follow-up and were included in the association analysis for treatment efficacy. Seventeen subjects who had adverse drug reactions (ADRs) to simvastatin (ADR group) could not complete the 6-month follow-up and were included in the association analyses for safety. Myalgia was observed in 15 of 17 subjects and was the only ADR included in the association analyses, but other common ADRs were also observed. Myalgia was defined as proximal or diffuse muscle pain, tenderness, or weakness, or both pain and weakness, with normal or slightly increased serum creatine phosphokinase levels. ABCB1 (1236C>T, 2677G>A/T, and 3435C>T), CYP3A4 (-392A>G), and CYP3A5 (6986A>G) allele variants were determined by polymerase chain reaction and restriction mapping. RESULTS: After adjustment for covariates, carriers of the ABCB1 1236T variant allele had a greater reduction in total cholesterol and low-density lipoprotein cholesterol with simvastatin treatment, as compared with homozygotes with the wild-type allele (-29.0% [95% confidence interval (CI), -25.9 to -32.5] versus -24.2% [95% CI, -19.0 to -29.3] [P = .042] and -39.6% [95% CI, -35.8 to -44.0] versus -33.8% [95% CI, -27.4 to -40.2] [P = .042], respectively). Similar results were observed for the 2677G>A/T polymorphism and haplotype data. The 1236T, 2677non-G, and 3435T alleles were less frequent in ADR cases than in the non-ADR group (P < .05 for all single-nucleotide polymorphisms). Haplotype analyses also demonstrated a reduction of the T-non-G-T haplotype frequency (20%) in patients in whom myalgia developed during simvastatin treatment, as compared with the non-ADR group (41.4%) (P = .03). No significant associations were observed between the CYP3A4 -392A>G and CYP3A5*3 allele variants and the efficacy or tolerability of simvastatin. CONCLUSIONS: Our data suggest an association of ABCB1 gene polymorphisms and the efficacy and safety of simvastatin.     

Effect of apolipoprotein C3 and apolipoprotein A1 polymorphisms on postprandial response to a fat overload in metabolic syndrome patients

ObjectivesApolipoprotein C-III (APOC3) is a component of triglyceride rich lipoproteins, and SstI polymorphism has been associated with hypertriglyceridemia. Apolipoprotein A-I (APOA1) is the major component of HDL and MspI polymorphism has been associated with APOA1 and HDL-C levels. Thus, we study the influence of these polymorphisms in the postprandial response in metabolic syndrome (MS).Design and methods73 MS patients and 21 healthy subjects underwent a fat overload, with measurements of their fasting and postprandial lipid profile. The APOC3 SstI and the APOA1MspI polymorphisms were genotyped.ResultsNo significant differences were found in the lipid profile with respect to the MspI genotype. Patients with the S2S2 APOC3 genotype had significantly higher fasting and postprandial triglyceride levels and postprandial APOC3 and chylomicron-triglyceride levels compared with the other SstI APOC3 genotypes.ConclusionsHomozygosity for the minor allele of the APOC3 SstI polymorphism was associated to a worse postprandial response in MS patients.     

Hypoadiponectinemia is associated with progression toward type 2 diabetes and genetic variation in the ADIPOQ gene promoter

OBJECTIVE: Adiponectin encoded by the ADIPOQ gene modulates insulin sensitivity and glucose homeostasis. The aim of the current study was to investigate whether ADIPOQ gene variants in the promoter region predict adiponectin levels and type 2 diabetes progression. RESEARCH DESIGN AND METHODS: A total of 550 subjects with increased risk of type 2 diabetes were investigated; they underwent a 75-g oral glucose tolerance test, repeated after 3 years. Adiponectin levels were analyzed, and two ADIPOQ promoter variant single nucleotide polymorphisms, -11391G>A and -11377C>G, were genotyped. RESULTS: Tertiles of the adjusted adiponectin levels were associated with single nucleotide polymorphism -11391G>A and -11377C>G haplotypes (P < 0.0001). Carriers of the intermediate/high-level haplotype combination showed a bisected diabetes risk at the 3-year follow-up and were characterized by a "regression" of glucose tolerance. Evolution of disease status correlates with preexisting low adiponectin levels at inclusion rather than with variation in adiponectin levels. CONCLUSIONS: We present data that gene variants in the ADIPOQ promoter region are associated with variations in adiponectin levels and thus with future type 2 diabetes and disease progression.     

Polymorphisms in the APOA1/C3/A4/A5 gene cluster and cholesterol responsiveness to dietary change.

BACKGROUND: The relationship between dietary composition and plasma lipids is to some extent genetically determined. It has been found that variants of some genes (e.g., apolipoprotein E and cholesterol 7-alpha hydroxylase) play an important role in changes in plasma lipid levels in response to dietary intervention. We analyzed the effect of variation in the apolipoprotein (APO) APOA1/C3/A4/A5 gene cluster on decreases in plasma cholesterol levels over an 8-year follow-up study. METHODS: Men (n=133) from the Czech population, for which dietary composition has markedly changed (red meat 80-->68 kg/person/year, animal fat 16-->9 kg/person/year, fruits and vegetables 133-->150 kg/person/year) were recruited. APOA1 (G-75>A and C83>T), APOC3 (C-482>T and C3238>G), APOA4 (Thr347>Ser and Gln360His) and APOA5 (T-1131>C, Ser19>Trp and Val153>Met) variants were analyzed by PCR and restriction analysis. Lipid levels were analyzed in 1988 and 1996. Dietary information was obtained from the Institute of Agricultural Economy. RESULTS: In APOA5 Ser19Ser homozygotes (n=105), plasma cholesterol was relatively stable over the years (6.1+/-1.3 and 5.6+/-1.0 mmol/L in 1988 and 1996), but the decrease was much higher in Trp19 carriers (n=27; 6.5+/-1.6 vs. 5.1+/-1.1 mmol/L). This difference in change is significant at p<0.005. Similarly, a better response to dietary changes was detected in carriers of the common APOA4 haplotypes Thr-347Thr/Gln360Gln and Thr347Ser/Gln360Gln (n=102; 6.3+/-1.3 and 5.5+/-1.1 mmol/L in 1988 and 1996, p<0.001). Total cholesterol was relatively stable over time in carriers (n=18) of at least one His360 allele and/or two Ser347 alleles (5.7+/-1.1 and 5.5+/-0.9 mmol/L in 1988 and 1996, n.s.). Other variants analyzed did not influence the change in lipid measurements over time. CONCLUSIONS: APOA4 and APOA5 variants may play an important role in the individual sensitivity of lipid parameters to dietary composition in men.     

Additive effect of interleukin-6 and C-reactive protein (CRP) single nucleotide polymorphism on serum CRP concentration and other cardiovascular risk factors

BACKGROUND: Serum C-reactive protein (CRP) levels, closely associated with cardiovascular disease (CVD) risk are influenced by CRP or interleukin-6 (IL-6) single nucleotide polymorphism (SNPs). However, it is still controversial. Therefore, we investigated the association of IL-6/CRP SNPs and serum CRP levels or other CVD risk factors in healthy adult Korean men. METHODS: In healthy adult men (age>or=20 years, n=677), we genotyped IL-6-572C>G and CRP SNPs (-717G>A, 1444C>T, 2147A>G) and measured anthropometric parameters, lipid profile, serum levels of CRP and IL-6 and insulin resistance. RESULTS: At IL-6-572C>G (n=677), subjects with G/G genotype (n=42) showed higher concentrations of CRP (P=0.027) and IL-6 (P=0.028) as compared with C allele carriers after age-adjustment (C/C: n=371, C/G: n=264). Fasting insulin and homeostatis model assessment insulin resistance (HOMA-IR) were also higher in G/G genotype. However, there were no significant differences in other metabolic biomarkers. Among 677 study subjects, 676 were genotyped at CRP-717G>A (G/G: n=513, G/A: n=150, A/A: n=13), 672 at CRP+1444C>T (C/C: n=580, C/T: n=85, T/T: n=7), and 668 at CRP+2147A>G (A/A: n=273, A/G: n=296, G/G: n=99). There were no significant differences in CRP concentrations and other markers related to CVD risk according to each CRP SNP genotype. However, we could find the additive gene-gene interaction between IL-6-572C>G and CRP SNPs on CRP concentration; subjects with the 'G/G' at IL-6-572 showed the highest CRP levels when they have variant allele at CRP SNPs after adjusted for age, body mass index, cigarette smoking and alcohol drinking (-717G>A: F=7.806, P=0.005; CRP+1444C>T: F=8.398, P=0.004; and CRP+2147A>G: F=7.564, P=0.006, respectively) Particularly, G allele carriers at CRP+2147A>G in subjects with IL-6-572G/G showed highest HOMA-IR (F=9.092, P=0.003). CONCLUSION: The present data showed that serum CRP levels and other CVD risk factors appeared more influenced by IL-6-572C>G rather than CRP SNPs (-717G>A, 1444C>T, and 2147A>G), however CRP levels and insulin resistance may be additively affected by IL-6-572 and CRP SNP, particularly when subjects with G/G genotype at IL-6-572 have allele variant at CRP SNPs.     

Modulation of steady-state kinetics of digoxin by haplotypes of the P-glycoprotein MDR1 gene

OBJECTIVE: We investigated the effect of polymorphisms in the P-glycoprotein (P-gp) MDR1 gene on steady-state pharmacokinetics of digoxin in Caucasians. According to earlier data, homozygous TT of the exon 26 complementary deoxyribonucleic acid (cDNA) 3435C>T polymorphism was associated with low P-gp expression in the human intestine. METHODS: Eight healthy male homozygous carriers of the wild-type exon-26 3435C>T (CC), 8 heterozygous subjects (CT), and 8 homozygous mutant (TT) subjects were selected. Seven further MDR1 polymorphisms were determined. Digoxin was administered orally twice daily on the first two study days; on days 3 to 5, 0.25 mg was given in the morning. On day 5, kinetic parameters were analyzed for genotype-phenotype and haplotype-phenotype relationships. RESULTS: The area under the plasma concentration-time curve from time zero to 4 hours [AUC(0-4)] (P =.042) and C(max) (P =.043) values of digoxin were higher in subjects with the 3435TT genotype than in those with the 3435CC. No influence of other single nucleotide polymorphisms (SNPs) on digoxin parameters was detected. Comparison of genotypes deduced from SNPs 2677G>T (exon 21) and 3435C>T revealed significant differences for AUC(0-4) (P =.034) and C(max) (P =.039), which were substantiated by haplotype analysis. Haplotype 12 (2677G/3435T), which had a frequency of 13.3% in a randomly drawn Caucasian sample (n = 687), was associated (Mann-Whitney test) with higher AUC(0-4) values (P =.009) than were found in noncarriers (mean +/- SD, 5.7 +/- 0.9 microg. h/L [n = 7] versus 4.8 +/- 0.9 microg. h/L [n = 17]). Haplotype 11 (2677G/3435C) had lower AUC(0-4) values (P =.013) compared with those of noncarriers (mean +/- SD, 4.7 +/- 0.9 microg. h/L [n = 16] versus 5.6 +/- 0.9 microg. h/L [n = 8]). Results of haplotype analysis match data of other MDR1 studies. CONCLUSION: Haplotype 12 codes for high values of AUC(0-4) and C(max) of orally administered digoxin. Analysis of MDR1 haplotypes is superior to unphased SNP analysis to predict MDR1 phenotype.     

Genetic profiling in healthy subjects from the Stanislas cohort based on 24 polymorphisms: effects on biological variables.

BACKGROUND: The association of genetic profiles with biological or clinical assessments is not clearly established especially among apparently healthy subjects. METHODS: A multivariate statistical analysis was performed on 24 polymorphisms related to the main metabolic pathways involved in cardiovascular diseases (CVDs). They were collected among 1551 healthy subjects of the Stanislas cohort to obtain genetic profiles. Association with biological variables was then studied at baseline (t0) and 5 years later (t5). RESULTS: Six genetic clusters were identified with relevant profiles and five polymorphisms from the selectin, apolipoprotein C3 and lipoprotein lipase genes (SELE-98G/T, APOC3-3175C/G, APOC3-482C/T, APOC3-1100C/T, LPL-93T/G) were sufficiently characteristic to associate 99.6% of the subjects with their corresponding cluster. A 5-year follow-up showed that clinical and biological measurements in relation to CVD risk factors already differ with triglyceride (p=0.009 for t0 and p=0.005 for t5) and high-density lipoprotein cholesterol (p=0.014 for t0 and p=0.003 for t5) for these previous genetic clusters. CONCLUSIONS: This study presents the hypothesis that SELE could be protective, whereas APOC3 could be associated with risk. It remains to be seen whether these polymorphisms will be predictive of CVD events among the selected clusters of different metabolic subtypes after a 10-year follow-up.     

Low-density lipoprotein receptor-related protein 5 and vitamin D receptor gene polymorphisms in relation to vitamin D levels in menopause.

BACKGROUND: The low-density lipoprotein receptor-related protein 5 (LRP5) gene has been recently identified as a novel candidate for osteoporosis. The c.4037C>T polymorphism in the LRP5 gene has been associated with bone mass variance in general population. In contrast, the IVS8+443G>A polymorphism in the vitamin D receptor gene (VDR) has not been investigated in relation to bone metabolism. The aim of the present study was to determine VDR IVS8+443G>A and LRP5 c.4037C>T polymorphisms in a cohort of 165 perimenopausal women and to associate the genotypes with biochemical and densitometric bone parameters in a subset of 112 postmenopausal women. METHODS: Both polymorphisms were assessed by restriction analysis of the PCR product. Calcium, parathyroid hormone, vitamin D metabolites and bone mineral density (BMD, g/cm(2)) at the hip and in the spine (L(1)-L(4)) were examined. RESULTS: The genotype frequencies of both IVS8+443G>A (UU 75.2%, Uu 23%, uu 1.8%) and c.4037C>T (CC 73.9% TC 23.6%, TT 2.4%) were comparable to other Caucasian female cohorts. Serum 25OH vitamin D levels, assessed in only 63 probands, were significantly associated with VDR genotypes (ANCOVA, pA polymorphism was significantly associated with circulating 25OH vitamin D in postmenopausal Caucasian women. The role of candidate gene polymorphisms in the vitamin D metabolic pathway requires further investigation.     

脑梗死患者载脂蛋白A5基因多态性与颈动脉粥样硬化程度的相关性研究

目的分析脑梗死患者载脂蛋白A5（apo A5）-1131T／C和553G／T2位点基因多态性及单倍型与颈动脉粥样硬化程度的关系。方法采用聚合酶链反应．限制性片段长度多态性（PCR-RFLP）技术，分别检测272例脑梗死患者apo A5-1131T／C和553G／T多态性位点不同基因型和等位基因的分布，采用SNP Alyze V6．0软件构建并分析2多态性位点的个体单倍型；颈动脉粥样硬化程度由颈总动脉（CCA）和颈内动脉（ICA）内膜中层厚度（IMT）评估。结果272例脑梗死患者中-1131CC基因型和-1131TT＋TC基因型人群的CCA IMT和ICA IMT间的差异无统计学意义（P〉0．05）；553GG基因型和553TT＋GT基因型人群的CCA IMT分别为（1．09±0．18）mm和（1．17±0．18）mm，差异有统计学意义（P〈0．05），而两人群的ICA IMT的差异无统计学意义（P〉0．05）。单倍型配对分析结果表明，4种常见单倍型配对TG-TG、TG-CG、TG-CT、CG-CG间ICA IMT水平差异有统计学意义（P〈0．05）。结论apo A5 553G／T位点基因变异可能与-1131T／C位点在脑梗死患者颈动脉粥样硬化的进程中起协同作用。     

Comparison of genetic polymorphisms of the NAT2 gene between Korean and four other ethnic groups

Background and objective:  N -acetyltransferase 2 (NAT2) is responsible for the acetylation of numerous drugs and in the transformation of aromatic and heterocyclinc amines into carcinogenic intermediates. Polymorphism of NAT2 may contribute to interindividual variability in such acetylation. The aim of this study was to determine the allele frequencies of polymorphisms of the NAT2 gene, analyse linkage disequilibrium (LD) block and haplotypes in Koreans and compare them with those of other ethnic groups.
Methods:  We analysed genetic polymorphisms in all functional promoter and exons of the NAT2 gene by direct sequencing of genomic DNA from 192 healthy Korean subjects. The LD and haplotype blocks of these subjects were constructed from genotype data using an expectation–maximization algorithm. We compared these allele frequencies, LD block and haplotype structure with those of other ethnic groups registered on the International HapMap database.
Results and discussion:  We identified 33 polymorphisms including six novel single nucleotide polymorphisms, −10778T>C, −10777A>G, −10351A>G, −10199C>T and −10104G>T in promoter and 578C>T in exon2 (T193M) in the Korean subjects tested. All allele frequencies reported in the Koreans were similar to those of Asians except for one allele (rs4345600, −9306A>G), whereas African and European groups had different frequencies in exon2. The haplotype structure and LD block among the five groups also revealed significant differences.
Conclusion:  Ethnic differences in the NAT2 genotype frequencies may be one of the important factors explaining variability in cancer incidence and drug toxicity. Our observations could be useful in assessing the susceptibility of different populations to cancer and contribute to better predictions of the pharmacokinetics and pharmacodynamics of drugs that are metabolized by NAT2, in different populations.     

广西壮族自治区南宁市新生儿GJB2 致聋基因的携带研究

目的 探讨南宁市新生儿GJB2致聋基因携带状况和突变位点与耳聋相关性。方法 收集2016～2018年期间在南宁市新生儿疾病筛查中心进行听力筛查未通过的1 007例新生儿血液,制成干血斑纸片,提取DNA,采用测序法进行GJB2全基因测序。统计新生儿GJB2基因突变的携带率,并结合新生儿听力损失确诊情况分析致聋基因突变特点。结果 1 007例新生儿中GJB2致聋基因突变携带率为55.21%(556/1 007),检测出GJB2基因突变位点16个,其中GJB2 c.109 G>A 突变携带率较高,占20.36%,其次是c.79 G>A 占10.03%,c.608 T>C 占7.65%,c.217 C>A 占7.15%,c.341 A>G 占6.85%,其它位点(包括c.11 G>A,c.-23+1 G>A, c.235del C, c.299 del AT,c.-121 G>A,c.464 A>G,c.147 C>G, c.676 G>T,c.316 T>G,c.-23-35 G>T 和c.368 C>A)突变携带率<0.1%。556例GJB2致聋基因突变者中有31例确诊为不同程度耳聋,4个致聋突变位点包括GJB2 c.109 G>A(26例),c.11 G>A(2例),c.235del C(2例)和c.299 del AT(1例),分别占耳聋患者比率是83.87%,6.45%,6.45%和3.23%。81例检出6个新突变位点c.-23-35 G>T,c.-121 G>A,c.464 A>G, c.217 C>A,c.147 C>G和 c.676 G>T及4例检出1个未明确致病性位点c.-23+1 G>A,另外有250例检出5个常见多态性突变位点。GJB2 c.109 G>A携带率与北京、台湾和上海比较差异有统计学意义(χ²=133.364,11.724,32.449,均P<0.05)。结论 南宁市新生儿GJB2致聋基因携带率较高,筛查出4个致聋突变位点,6个新突变位点及1个未明确致病位点,明确了致聋突变位点以c.109 G>A纯合子突变为主,基因突变特点有明显的地域性差异。     

TotalPlex gene amplification using bulging primers for pharmacogenetic analysis of acute lymphoblastic leukemia

Genetic polymorphism among patients with acute lymphoblastic leukemia (ALL) is an important factor in the effectiveness and toxicity of anti-leukemic drugs. Genotyping of various polymorphisms that impact the outcome of anti-leukemic drug therapy (pharmacogenetics) presents an attractive approach for developing individualized therapy. We developed an easy and accurate method of analyzing multiple genes using a small amount of DNA, which we termed TotalPlex amplification. We used 16 pairs of specific bulging specific primers (SBS primers) for simultaneous amplification of 16 loci in a single PCR tube. Sixteen single nucleotide polymorphisms (SNPs) (CYP3A4*1B A>G, CYP3A5*3 G>A, GSTP1 313 A>G, GSTM1 deletion, GSTT1 deletion, MDR1 exon 21 G>T/A, MDR1 exon 26 C>T, MTHFR 677 C>T, MTHFR 1298 A>C, NR3C1 1088 A>G, RFC 80 G>A, TPMT 238 G>C, TPMT 460 G>A, TPMT 719 A>G, VDR intron 8 G>A, VDR FokI T>C) that have been implicated in the pharmacogenetics of ALL therapy were analyzed by TotalPlex amplification and SNP genotyping. We successfully amplified specific gene fragments using 16 pairs of primers in one PCR reaction tube with minimal spurious amplification products using TotalPlex amplification coupled to a multiplexed bead array detection system. The genotypes of 16 loci from 34 different genomic DNA (gDNA) samples derived using the TotalPlex system were consistent with the results of several standard genotyping methods, including automatic sequencing, PCR restriction fragment length polymorphism (RFLP) analysis, PCR, and allele-specific PCR (AS-PCR). Thus, the TotalPlex system represents a useful method of amplification that can improve the time, cost, and sample size required for high-throughput pharmacogenetic analysis of SNPs.     

Identification and functional analysis of common human flavin-containing monooxygenase 3 genetic variants

Flavin-containing monooxygenases (FMOs) are important for the disposition of many therapeutics, environmental toxicants, and nutrients. FMO3, the major adult hepatic FMO enzyme, exhibits significant interindividual variation. Eighteen FMO3 single-nucleotide polymorphism (SNP) frequencies were determined in 202 Hispanics (Mexican descent), 201 African Americans, and 200 non-Latino whites. Using expressed recombinant enzyme with methimazole, trimethylamine, sulindac, and ethylenethiourea, the novel structural variants FMO3 E24D and K416N were shown to cause modest changes in catalytic efficiency, whereas a third novel variant, FMO3 N61K, was essentially devoid of activity. The latter variant was present at an allelic frequency of 5.2% in non-Latino whites and 3.5% in African Americans, but it was absent in Hispanics. Inferring haplotypes using PHASE, version 2.1, the greatest haplotype diversity was observed in African Americans followed by non-Latino whites and Hispanics. Haplotype 2A and 2B, consisting of a hypermorphic promoter SNP cluster (-2650C>G, -2543T>A, and -2177G>C) in linkage with synonymous structural variants was inferred at a frequency of 27% in the Hispanic population, but only 5% in non-Latino whites and African Americans. This same promoter SNP cluster in linkage with one or more hypomorphic structural variant also was inferred in multiple haplotypes at a total frequency of 5.6% in the African-American study group but less than 1% in the other two groups. The sum frequencies of the hypomorphic haplotypes H3 [15,167G>A (E158K)], H5B [-2650C>G, 15,167G>A (E158K), 21,375C>T (N285N), 21,443A>G (E308G)], and H6 [15,167G>A (E158K), 21,375C>T (N285N)] was 28% in Hispanics, 23% in non-Latino whites, and 24% in African Americans.