CYP3A5基因和MDR1基因位点的单核苷酸多态性与CML细胞遗传学复发风险的关系分析

目的:分析CYP3A5基因和MDR1基因位点的单核苷酸多态性(SNP)与慢性髓系白血病(CML)细胞遗传学复发风险的关系。方法:收集本院收治的90例行伊马替尼治疗的CML患者的临床资料,根据有无复发进行分组,并分析CYP3A5基因和MDR1基因位点的SNP与CML细胞遗传学复发风险的关系。结果:无细胞遗传学复发者41例(无复发组),复发者49例(复发组),随访36个月。相比MDR1基因位点中的C3435T、C1236T的TT+CT基因型的患者,CC基因型的患者细胞遗传学复发的几率显著升高(P 0. 05)。相比MDR1基因位点中的C3435T的CT+CC基因型的患者,TT基因型的患者细胞遗传学复发的几率显著下降(P 0. 05)。相比MDR1基因位点中的C1236T、C3435T的CT、CC基因型患者,TT基因型者无复发生存期明显延长(P 0. 05)。相比无复发组,复发组中性粒细胞减少症(29. 27%vs 71. 43%)、血液毒性(39. 02%vs 61. 22%)的发生率显著升高(P 0. 05)。伊马替尼剂量(OR=2. 95,95%CI:1. 37-7. 76)与MDR1基因中的C3435T基因型(OR=0. 09,95%CI:0. 05～0. 72)是CML患者细胞遗传学复发的影响因素(均P 0. 05)。结论:伊马替尼治疗剂量与MDR1基因中的C3435T、C1236T基因型对CML患者细胞遗传学复发造成一定的影响,其中MDR1基因中的C3435T基因型对评估患者细胞遗传学复发风险具有一定的预测价值,因此可作为一种临床潜在的生物标志物。     

CD40基因-1C/T位点基因多态性与系统性红斑狼疮发病、临床特征及SLEDAI指数的关系

目的探讨CD40基因5,非翻译区-1位点C/T单核甘酸多态性与汉族人群系统性红斑狼疮(SLE)发病、临床特征及系统性红斑狼疮疾病活动指数(SLEDAI)的关系。方法选取2013年1月至2016年1月收集的系统性红斑狼疮患者90例(病例组),同期体检健康对象90例作为对照组。采用聚合酶链反应-限制性内切酶技术检测两组人群CD40基因-1C/T位点基因多态性,并分析等位基因与基因型频率与临床特征、SLEDAI评分的关系。结果病例组的CC基因型频率(42.22%)显著高于对照组(24.44%)(P0.05),病例组的CT、TT基因型与对照组比较差异无统计学意义(P0.05);病例组等位基因C的频率61.67%显著的高于对照组的48.33%(P0.05);病例组的CC基因型患者的SLEDAI评分显著的高于CT、TT基因型的患者(P0.05),病例组的CT基因型患者的SLEDAI评分显著的高于TT基因型的患者(P0.05);病例组90例患者,CC基因型患者的的关节炎、盘状红斑、颊部红斑、口腔溃疡发生率显著的高于基因型CT、TT患者(P0.05);CT基因型患者的的关节炎、狼疮肾炎、盘状红斑、颊部红斑发生率显著的高于基因型TT患者(P0.05)。结论 CD40基因-1C/T位点CC基因型会增加SLE患者的易感性,并且与患者病情有关。     

乳腺癌MDR1基因多态性与紫杉类药物化疗血液毒副反应的关系

目的:探讨MDR1基因多态性与乳腺癌紫杉类药物为基础化疗毒副反应间的关系,为临床个体化药物治疗提供信息。方法:筛选93例汉族女性乳腺癌患者,利用PCR-RFLP技术检测其外周血MDR1 C3435T和G2677T/A基因型。结果:在本组病例中,白细胞和中性粒细胞减少症(Ⅲ～Ⅳ度)的发生频率相对较高,分别为27.2%和25%。MDR1 C3435T各基因型患者间中性粒细胞减少反应差异显著,CC型发生频率为5%,低于CT和TT型(26.3%和46.7%;χ2=8.075,P=0.018;95%CI0.017～0.022);未发现G2677T/A多态性与血液毒性的关联。结论:MDR1 3435T等位基因携带者在紫杉类药物治疗后发生中性粒细胞减少症的风险可能较大。     

终末期肾脏病患者MDR1基因多态性和二氢吡啶类钙拮抗剂诱导牙龈增生的关系

目的探讨终末期肾脏病(endstage renal disease,ESRD)患者MDR1基因多态性和二氢吡啶类钙拮抗剂(calcium channel blockers,CCB)诱导牙龈增生的关系。方法入选183例ESRD高血压患者,根据所使用的CCB分为3组,同时检测MDR1C3435T基因多态性。结果共有152例患者最终纳入分析,84例发生牙龈增生,其中硝苯地平54例、非洛地平15例和氨氯地平15例,各组患者牙龈增生的发生率无显著性差异(χ~2=4.968,P=0.083);且MDR1C3435T基因频率分布符合Hardy-Weinberg平衡分布(CC=28.3%,CT=50.7%,TT=21.0%;χ~2=0.032,P=0.985);同时各基因型牙龈增生比例无显著差异(χ~2=3.690,P=0.158),3个基因型牙龈增生严重程度无显著差异(F=0.406,P=0.667)。结论 MDR1C3435T基因多态性可能与ESRD高血压患者使用CCB诱导牙龈增生无显著相关,尚需要在更大样本中进一步检验。     

多药耐药基因1 C3435T基因多态性对环孢素A药物动力学影响的Meta分析

背景：多药耐药基因1 C3435T基因多态性影响着P-糖蛋白的功能和表达,从而影响环孢素A血药浓度,产生个体差异。目前多药耐药基因1 C3435T基因多态性对环孢素A药物动力学影响的研究结果不一。目的：基于国内外报道的国内相关研究,系统评价多药耐药基因1 C3435T基因多态性与环孢素A药物动力学的关系。方法：计算机检索Cochrane图书馆、Medline、Plumbed、CNKI、万方等数据库,并辅以文献追溯的方法,收集国内外公开发表的国内相关病例对照、队列研究。检索年限均为从建库至2011-12-31。按纳入、排除标准筛选文献并评价纳入研究的质量后,采用RevMan 5.1软件进行Meta分析。结果与结论：共纳入9篇文献,合计893例患者。Meta分析结果表明,多药耐药基因1 3435CC的环孢素A剂量调整谷浓度显著低于CT基因型（P=0.007）和TT基因型（P=0.0006）;亚组分析显示,肾移植后患者多药耐药基因13435CC的环孢素A剂量调整谷浓度显著低于CT基因型（P〈0.00001）及TT基因型（P=0.0003）;血液系统疾病患者多药耐药基因1 3435CC的环孢素A剂量调整谷浓度显著低于TT基因型（P=0.004）。多药耐药基因1 3435CC的环孢素A剂量调整峰浓度显著低于TT基因型（P=0.005）。提示多药耐药基因1 C3435T基因多态性对环孢素A血药浓度有影响,CC基因型患者血药浓度低于TT基因型。还需要大样本、前瞻性研究来探讨多药耐药基因1 C3435T基因多态性与环孢素A药物动力学的关系。     

系统性红斑狼疮患者纤溶酶原激活物抑制剂-1基因4G/5G及多药耐药性蛋白基因C3435T多态性分布特征

目的探讨系统性红斑狼疮(systemic lupus erythematosus,SLE)患者纤溶酶原激活物抑制剂-1(plasminogen activator inhibitor-1,PAI-1)基因4G/5G及多药耐药性蛋白(ATP-binding cassette subfamily B member 1,ABCB1)基因C3435T多态性分布特征。方法 79例SLE患者依据脏器损伤情况分为SLE继发股骨头坏死(osteonecrosis of the femeral head,ONFH)组20例,狼疮肾炎(lupus nephritis,LN)组37例,其他组22例。采用数字荧光分子杂交技术检测3组外周血PAI-1基因4G/5G和ABCB1基因C3435T多态性,比较3组PAI-1基因高危4G4G型、ABCB1基因C3435T位点高危CC型分布频率。结果79例患者PAI-1基因4G4G、4G5G、5G5G基因型频率分别为29.1%、51.9%、19.0%,ABCB1基因C3435T位点CC、CT、TT基因型频率分别为41.7%、39.2%、19.1%;SLE-ONFH组、LN组PAI-1基因高危4G4G型分布频率(35.0%、35.1%)与其他组(13.6%)比较差异无统计学意义(P0.05);SLE-ONFH组、LN组ABCB1基因C3435T位点高危CC型分布频率(50.0%、51.4%)高于其他组(18.2%)(P0.05);SLE-ONFH组PAI-1基因高危4G4G型、ABCB1基因C3435T位点高危CC型分布频率与LN组比较差异无统计学意义(P0.05)。结论 ABCB1基因C3435T位点高危CC型可能与SLE患者继发ONFH、LN有关。     

转化生长因子-β1与冠状动脉支架内再狭窄关系的探讨

目的探讨转化生长因子(TGF)-β1血浆水平及TGF-β1基因-509C/T单核苷酸多态性(SNP)与重庆地区汉族人群经皮冠状动脉介入治疗术后支架内再狭窄(ISR)发生的关系。方法回顾性纳入冠状动脉支架术后行冠状动脉造影随访的患者368例,根据复查造影的结果将其分为ISR组152例和无再狭窄(NISR)组216例。酶联免疫吸附试验检测血浆TGF-β1水平,采用聚合酶链反应-限制片段长度多态性及基因测序的方法检测TGF-β1基因-509C/T多态的基因型。结果 TGF-β1基因-509C/T多态的3种基因型和等位基因分布频率ISR组和NISR组差异均有统计学意义(P0.05),TT基因型和T等位基因在ISR组所占比例显著增加,与NISR组差异有统计学意义(P0.05);血浆TGF-β1水平ISR组高于NISR组,差异有统计学意义(P0.05),ISR组TGF-β1基因-509C/T多态TT和CT基因型携带者血浆TGF-β1水平均显著高于NISR组,差异有统计学意义(P0.05),各组内TT基因型血浆TGF-β1水平均高于CC和CT基因型,CT基因型又高于CC基因型,组内比较差异均有统计学意义(P0.05)。Logistic回归分析显示,TT基因型、T等位基因(CT+TT基因型)和血浆TGF-β1是ISR发生的独立危险因素(OR值分别为1.82、1.61和2.01,P0.05)。结论高血浆TGF-β1水平、TT基因型及T等位基因携带者显著增加ISR的风险。     

多药耐药基因多态性和单倍体对环孢素A血药浓度的影响

目的探讨中国健康志愿者中多药耐药基因(MDR1)12外显子C1236T、21外显子G2677T/A和26外显子C3435T多态性及3个位点单倍体连锁不均衡性对环孢素A(CsA)药代动力学特性的影响。方法高效液相色谱法(HPLC)测定20名健康男性单次口服CsA500mg后,24h中不同时间点的血药浓度。采用聚合酶链反应(PCR)结合基因测序法测定3个位点的基因多态性和单倍体类型。结果20名男性健康志愿者中,C1236T位点1名为CC型,8名为CT型,11名为TT型;G2677A/T位点4名为GG型,7名为GT型,4名为AT型,5名为TT型;C3435T位点5名为CC型,11名为CT型,4名为TT型;MDR1的C1236T和G2677A/T的基因多态性与峰浓度(Cmax)和药时曲线下面积(AUC0inf)差异均无统计学意义(均P>0.05),C3435T的基因多态性与Cmax无相关性(P>0.05),而与AUC0inf相关(P<0.05)。CC型、CT型和TT型的Cmax分别为2124.7±179.4ng/ml、1934.2±372.8ng/ml和1765.2±415.6ng/ml;AUC0inf分别为13922.4±2881.5ng/h-1·ml、11511.8±2192.1ng/h-1·ml和8514.9±1063.4ng/h-1·ml;至少含有1个C等位基因的基因型(CC型和CT型),二者的AUC0inf比TT型增高49%。单倍体分析表明,26与12和21外显子间存在单核苷酸多态性的连锁不均衡性,不同单倍体类型对CsA药动力学特性无影响(P>0.05)。结论MDR1C3435T的多态性可能是口服CsA后,生物利用度变异大的影响因素。     

脑卒中患者MTHFR基因多态性与H型高血压的相关性

目的 研究脑卒中患者中亚甲基四氢叶酸还原酶(MTHFR) C677T基因多态性和基因分布频率,探讨MTHFR基因多态性与H型高血压及血清同型半胱氨酸(Hcy)的相关性。方法 选取2018年7月至2018年12月在中国科学技术大学附属第一医院神经内科住院的122例患有高血压的脑卒中住院患者。查询病历系统采集患者基线及生化资料,采用PCR-芯片法对MTHFR C677T基因多态性检测,按照基因型将患者分为三组(CC、CT和TT)。结果 研究人群中有72%为H型高血压,男性患者多于女性,差异有统计学意义(P 0. 05);男性患者MTHFR C677T突变位点T等位基因频率为56. 04%高于女性患者40. 32%T等位基因频率,差异有统计学意义(P 0. 05); TT基因型患者血清Hcy水平高于CT和CC基因型患者,与之相反,TT基因型患者叶酸和维生素B12水平低于CT和CC基因型患者,差异有统计学意义(P 0. 05); TT组存在高同型半胱氨酸患者频率高于CT组和CC组,差异有统计学意义(P 0. 05)。结论 MTHFR C677T基因多态性是H型高血压的重要遗传风险因素,对脑卒中高血压患者MTHFR C677T基因型检测有助于临床精准诊疗。     

深圳青年高同型半胱氨酸血症MTHFR C677T基因无创纳米筛查及基因多态性研究

目的为深圳青年高同型半胱氨酸血症防治提供准确快速的转化医学药物服用方案指导,实现基因层面预防。方法选取深圳青年中进行MTHFR C677T基因无创纳米筛查的受检者,从中随机抽取100例基因检测结果为正常的受检者作为对照组,100例患有高同型半胱氨酸血症的患者设为病例组,对两组对象患者不同高同型半胱氨酸水平和MTHFRC6677T基因型的相关性进行对比。并将深圳地区青年高同型半胱氨酸血症MTHFR C677T基因型与其他地区患者比较。结果两组对象MTHFR基因频率(TT、CT、CC)和等位基因频率(T、C)的差异均有显著性(P0.05),病例组患者MTHFR基因频率中TT、等位基因频率中T高于对照组,而MTHFR基因频率中CT和CC、等位基因频率中C低于对照组;两组对象不同基因型(TT、CT、CC)的血浆Hcy水平具有显著差异(P0.05),且均有病例组患者血浆Hcy水平明显高于对照组;不同地区高同型半胱氨酸血症患者MTHFR C677T基因型进行比较,差异具有统计学意义(P0.05),基因型中CC最高为湖南地区(53.33%)、最低为美国(17.85%);CT最高为美国(48.07%)、最低为湖南地区(34.16%);TT最高为深圳地区(35.00%)、最低为美国(3.57%)。结论通过深圳青年高同型半胱氨酸血症MTHFR C677T基因多态性表现的研究,能够达到对高同型半胱氨酸血症高危人群早期基因预警筛查目的。     

A variant 2677A allele of the MDR1 gene affects fexofenadine disposition

BACKGROUND AND OBJECTIVES: There have been considerable disagreements regarding the influence of MDR1 (ABCB1) polymorphisms on the disposition of P-glycoprotein (P-gp) substrates. We speculated that the unknown function of the A allele of exon 21 G2677T/A (Ala893Ser/Thr) provides one of the reasons for the contradictory results. This study was performed to clarify the effects of major MDR1 gene polymorphisms, including a variant A allele in exon 21, on fexofenadine pharmacokinetics. METHODS: We investigated the occurrence of 3 high-frequency single-nucleotide polymorphisms (SNPs) in exons 12 (C1236T), 21 (G2677T/A), and 26 (C3435T) of the MDR1 gene in 232 healthy Koreans, using a polymerase chain reaction-restriction fragment length polymorphism method, and performed haplotype analysis on these 3 SNPs. A single oral dose of 180 mg fexofenadine hydrochloride was administered to 33 healthy Korean male volunteers, who were divided into 6 groups based on the MDR1 genotype for the G2677T/A polymorphism in exon 21 and the C3435T polymorphism in exon 26. RESULTS: A strong linkage disequilibrium was observed among the 3 SNPs. The frequencies of the 4 major haplotypes, 1236C-2677A-3435C, C-G-C, T-G-C, and T-T-T, were 16.4%, 18.6%, 21.6%, and 32.2%, respectively. Fexofenadine disposition varied considerably among the groups. In the 2677AA/3435CC genotype group (n=3), the values of area under the concentration-time curve from time 0 to 24 hours [AUC(0-24)] were significantly lower (P=.014) than those of the other 5 genotype groups (GG/CC, GT/CT, TT/TT, GA/CC, and TA/CT). As compared with the 2677GG/3435CC subjects, the AUC(0-24) values were 17% lower in the 2677AA/3435CC subjects and 47% higher in the 2677TT/3435TT subjects (GG/CC versus AA/CC versus TT/TT, 4017 +/- 1137 ng . h/mL versus 3315 +/- 958 ng . h/mL versus 5934 +/- 2,064 ng . h/mL; P=.018). By stratification for genotypes at position 3435, homozygous 3435TT subjects were found to have significantly higher AUC(0-24) (P=.024) and maximum plasma concentration (P=.040) values than CC subjects [AUC(0-24), 5934 +/- 2064 ng . h/mL versus 3998 +/- 1241 ng . h/mL; maximum plasma concentration, 958 +/- 408 ng/mL versus 673 +/- 242 ng/mL]. CONCLUSIONS: The plasma concentrations of fexofenadine after a single oral administration were lower in 2677AA/3435CC subjects than in subjects with the other 5 genotype combinations of the SNPs of G2677T/A and C3435T. These findings confirm the importance of analyzing MDR1 haplotypes and provide a plausible explanation for the conflicting results regarding the effect of MDR1 polymorphisms on the disposition of P-gp substrates.     

No effect of MDR1 C3435T variant on loperamide disposition and central nervous system effects

BACKGROUND: The MDR1 gene encodes the efflux transporter P-glycoprotein, which is highly expressed in the small intestine and in the blood-brain barrier. A major function of P-glycoprotein is to limit the absorption and central nervous system exposure of numerous xenobiotics. A genetic polymorphism in the MDR1 gene (C3435T) has been associated with changes in the intestinal expression level and function of P-glycoprotein. The aim of this study was to investigate the effect of this polymorphism on disposition and brain entry of the P-glycoprotein substrate loperamide. METHODS: Healthy white volunteers were genotyped for the MDR1 C3435T polymorphism, and a 16-mg oral dose of loperamide was administered to 8 subjects with the 3435TT genotype and 8 subjects with the 3435CC genotype. Plasma levels of loperamide were determined by liquid chromatography-tandem mass spectrometry. Loperamide-induced respiratory depression was detected as the ventilatory response to carbon dioxide and was used as a measure of central nervous system side effects. RESULTS: We found no significant difference in loperamide pharmacokinetics between individuals homozygous for the C and the T alleles in position 3435 of MDR1, as follows: peak plasma drug concentration, 3164 +/- 1053 pg/mL and 3021 +/- 984 pg/mL; area under the concentration-time curve from 0 to 8 hours, 14414 +/- 4756 pg. h/mL and 14923 +/- 6466 pg. h/mL; and time to peak plasma drug concentration, 3.9 +/- 1.4 hours and 3.9 +/- 2.6 hours for the MDR1 3435CC and 3435TT genotypes, respectively (P >.05, for all parameters). Hypercapnic ventilatory response changed only minimally after ingestion of loperamide (the coefficient of variation during the 0- to 8-hour period was 21% +/- 14% for the sample population), and there was no MDR1 3435 genotype-related effect on respiratory response. Carriers of the 2 major MDR1 haplotypes, MDR1*1 and MDR1*13, did not differ in their response to loperamide. CONCLUSION: There was no association between the MDR1 C3435T variation and plasma levels or central nervous system effects of the P-glycoprotein substrate loperamide in a white study population. The MDR1 haplotype structure was quite variable and supports the use of haplotypes instead of single nucleotide polymorphisms in determining clinical consequences of genetic variation.     

IRF6和RARA基因多态性与非综合征性唇腭裂的相关性研究

目的探讨干扰素调节因子-6(IRF6)基因rs2235371位点和视黄酸受体-α(RARA)基因rs2229773位点单核苷酸多态性(SNP)与非综合征性唇腭裂的关系,以及2个位点在患者和健康者之间的基因型和等位基因型频率差异。方法选取153例非综合征性唇腭裂(NSCL/P)患者作为NSCL/P组,体检健康者150例作为健康对照组。运用聚合酶链式反应-限制性片段长度多态性(PCR-RELF)技术,分析IRF6、RARA基因的多态性,比较2组研究对象基因型和等位基因型频率差异。结果 IRF6基因rs2235371位点基因型CC、TT和等位基因C、T频率在NSCL/P组和健康对照组的分布,差异有统计学意义(P0.05),NSCL/P组等位基因C频率高于健康对照组,差异有统计学意义(P0.05)。RARA基因rs2229773位点基因型CT、TT频率在NSCL/P组和健康对照组的分布,差异有统计学意义(P0.05),NSCL/P组基因型为CT杂合子,显著多于健康对照组,差异有统计学意义(P0.05)。结论 NSCL/P与IRF6基因rs2235371位点等位基因C及RARA基因rs2229773位点CT基因型具有相关性。     

精神分裂症患者醌氧化还原酶1 C609T 多态性与血脂水平相关性研究

目的：探讨醌氧化还原酶1 C609 T 基因多态性与精神分裂症患者血脂水平的相关性。方法对328例精神分裂症患者血脂水平及醌氧化还原酶1 C609 T基因多态性进行检测分析。结果本组患者醌氧化还原酶1 C609T位点CC、CT 和 T T基因型频率分别为43．9％、42．1％和14．0％；C和T等位基因频率分别为66．3％和33．7％。醌氧化还原酶1 C609T基因型频率、等位基因频率与患者血脂水平均无显著相关性（P＞0．05）。结论醌氧化还原酶1基因C609T位点在精神分裂症患者中存在多态性，其基因型频率、等位基因频率与患者的血脂水平无显著相关性。     

同型半胱氨酸及C677T基因多态性与妊娠期糖尿病关系分析

目的探讨同型半胱氨酸(Hcy)及亚甲基四氢叶酸还原酶(MTHFR)基因C677T位点多态性与妊娠期糖尿病(GDM)的相关性。方法以91例GDM孕妇为GDM组,123例正常妊娠孕妇为对照组,检测MTHFR C677T基因多态性及血清Hcy、血糖水平。结果 GDM组Hcy水平高于对照组,Hcy水平与空腹血糖水平呈正相关(P0.05)。GDM组与对照组MTHFR C677T多态性基因CC、CT、TT分布频率比较差异有统计学意义(P0.05)。GDM组TT型基因携带者Hcy水平高于CC型基因携带者(P0.05)。结论 Hcy与GDM的发生、发展密切相关。MTHFR C677T基因多态性可能通过影响Hcy水平而影响GDM的发生、发展。     

多药耐药基因1C3435T多态性在癫痫患者中的分布及其与癫痫耐药的关系

目的研究多药耐药基因1（MDR1）C3435T多态性在癫痫患者中的分布特点,并探讨其与癫痫患者对抗癫痫药物反应的关系。方法收集的230例癫痫患者中,其中对抗癫痫药物不敏感的患者（耐药组）108例和敏感的患者（敏感组）122例,选择90例正常人作对照;再按癫痫类型和病因选取耐药组和敏感组。用多聚合酶链反应扩增后继以限制性内切酶片断长度分析法（PCR-RFLP方法）分别测定各组患者MDR1基因C3435T位点的基因型频率和等位基因频率。然后对耐药组、敏感组和对照组的基因型频率和等位基因频率进行比较。结果 （1）总耐药组和总敏感组病例中的基因型比较和等位基因频率比较,差异均无统计学意义（P〉0.05）。（2）不同癫痫类型中,耐药组和敏感组基因型频率和等位基因频率比较均无统计学意义（P〉0.05）。（3）在不同病因的癫痫患者中,耐药组和敏感组病例比较,结果基因型频率和等位基因频率的差异均无统计学意义（P〉0.05）。结论无论在考虑癫痫分型和病因还是不考虑分型和病因,MDR1C3435T位点多态性与癫痫患者对抗癫痫药物的耐药性均没有关系。     

Peroxisome proliferator-activated receptor gamma gene polymorphism is associated with serum triglyceride levels and body mass index in Japanese type 2 diabetic patients

Peroxisome proliferator-activated receptor gamma (PPARgamma) controls adipocyte differentiation and regulates lipid and glucose homeostasis. Therefore, the PPARgamma gene may affect insulin sensitivity and resistance. We analyzed the relationship between C/T exon 6 polymorphism of the PPARgamma gene and various clinical parameters in type 2 diabetic patients. There were no significant differences in the frequencies of genotype and allele between diabetic patients with and without nephropathy. Diabetic patients were divided into two groups: patients bearing at least one T allele (CT/TT), and patients with no T allele (CC). Levels of serum triglyceride and body mass index (BMI) were significantly higher in the CT/TT genotype group than in the CC genotype group. Since obesity affects insulin resistance, the diabetic patients were also divided into two groups: those with a BMI of <23, and those with a BMI of >23. In patients with a BMI of <23, there was no significant change in the levels of glycosylated hemoglobin A1c (HbA1c) between the CC and CT/TT genotype groups. However, in patients with a BMI of >23, HbA1c levels were significantly higher in the CT/TT genotype group than in the CC genotype group. It appears that the CT/TT genotype with PPARgamma gene polymorphism may contribute to higher BMI and higher serum triglyceride and HbA1c levels in Japanese type 2 diabetic patients.     

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.