尿苷二磷酸葡聚糖转移酶1A8*2在云南健康佤族、白族和藏族基因多态性研究

目的:了解云南佤族、白族和藏族人群中尿苷二磷酸葡聚糖转移酶1A8*2的基因多态性,并与其他种族比较,了解种族差异。方法:使用聚合酶链反应-限制性片段长度多态性的方法对云南144名佤族、115名白族和252名藏族健康个体进行尿苷二磷酸葡聚糖转移酶1A8*2基因分型。计算各民族基因型频率,并检验是否符合Hardy-Weinberg平衡。用χ2检验比较佤族、白族和藏族人群以及已报道的其他民族的基因型频率和等位基因频率。结果:云南佤、白、藏三族健康人群尿苷二磷酸葡聚糖转移酶1A8*2基因频率与文献报道的其他种族比较结果表明,佤族健康人群CC、CG、GG基因型频率分别为16.7%、52.8%和30.5%,白族分别为35.7%、50.4%和13.9%,藏族的分别为8.3%、78.2%和13.5%。佤族、白族和藏族尿苷二磷酸葡聚糖转移酶1A8*2 G等位基因频率分别为56.9%、39.1%和52.6%,与非洲裔美国人及德国高加索人比较其突变率明显增高;白族与日本人比较突变率增高,但突变率低于汉族;云南白族尿苷二磷酸葡聚糖转移酶1A8*2 G等位基因频率与佤族和藏族均有统计学差异(P<0.01),但佤族和藏族之间无差异。上述所有基因型分布比例都符合Hardy-Weinberg平衡。结论:云南佤族、白族和藏族尿苷二磷酸葡聚糖转移酶1A8*2的突变发生情况均有自己的特点,在临床应用相关药物时,进行这些位点基因型检测,将有助于指导临床个体化用药。     

江苏地区汉族儿童多药耐药基因3个单核苷酸多态性位点的单倍型研究

目的分析江苏汉族人群多药耐药基因-1（MDR1）的单核甘酸多态（12外显子1236C→T突变、21外显子2677G→T/A突变、26外显子3435C→T突变）及其构成的单倍型分布。方法通过多重单碱基延伸反应（SNaPshotSNP分型技术）对江苏地区170名健康儿童的MDR1C1236T、G2677T/A、C3435T的SNP位点进行基因分型,统计各基因型频率。UNPHASED软件对MDR1的SNPs（C1236T-G2677T/A-C3435T）进行单倍型分析。结果在170例儿童中,等位基因1236T、2677T、2677A、3435T频率分别为63.5%、37.4%、17.0%和35.0%。基因型频率分布符合Hardy-Weinberg平衡（HWE）,差异无统计学意义（P〉0.05）。MDR1的1236、2677、3435三个位点间（C1236T-G2677T/A-C3435T）存在连锁不平衡性,以TTT（31.8%）、TGC（25.3%）、CGC（17.7%）和CAC（16.2%）四种单倍型为主。结论江苏地区汉族人群MDR1的单核甘酸多态及单倍型分布具有自己的特点。在临床应用相关药物时,进行基因型及单倍型检测,将有助于指导临床个体化用药。     

江苏地区汉族儿童多药耐药基因3个单核苷酸多态性位点的单倍型研究

目的 分析江苏汉族人群多药耐药基因-1(MDR1)的单核甘酸多态(12外显子1236 C→T突变、21外显子2677G→T/A突变、26外显子3435C→T突变)及其构成的单倍型分布.方法 通过多重单碱基延伸反应(SNaPshot SNP分型技术)对江苏地区170名健康儿童的MDR1 C1236T、G2677T/A、C3435T的SNP位点进行基因分型,统计各基因型频率.UNPHASED软件对MDR1的SNPs(C1236T-G2677T/A-C3435T)进行单倍型分析.结果 在170例儿童中,等位基因1236T、2677T、2677A、3435T频率分别为63.5%、37.4%、17.0%和35.0%.基因型频率分布符合Hardy-Weinberg平衡(HWE),差异无统计学意义(P>0.05).MDR1的1236、2677、3435三个位点间(C1236T-G2677T/A-C3435T)存在连锁不平衡性,以TTT(31.8%)、TGC(25.3%)、CGC(17.7%)和CAC(16.2%)四种单倍型为主.结论 江苏地区汉族人群MDR1的单核甘酸多态及单倍型分布具有自己的特点.在临床应用相关药物时,进行基因型及单倍型检测,将有助于指导临床个体化用药.     

MDR1基因C3435T多态性对替米沙坦稳态血药浓度及降压疗效的影响

目的：探讨多药耐药基因MDR1 C3435T（exon 26）位点基因多态性对替米沙坦在原发性高血压患者中的稳态血药浓度及降压疗效的影响。方法：采用聚合酶链反应（PCR）和限制性内切酶片段多态性（RFLP）的方法对连续30 d每天口服40 mg替米沙坦的61名高血压患者的MDR1C3435T位点进行基因分型。使用高效液相色谱-荧光检测法（HPLC-FLD）测定高血压患者的稳态血药浓度,使用水银血压计测量治疗前、后高血压患者的血压值。比较不同基因型间高血压患者的稳态血药浓度及降压疗效的差异。结果：在61例中老年原发性高血压患者中,MDR1 C3435T CC型纯合子的频率为39.34%,TT型纯合子的频率为11.48%,CT型杂合子的频率为49.18%,MDR1C3435T位点等位基因发生率在健康人群和高血压患者间差异无统计学意义。3种基因型高血压患者的稳态血药浓度及降压有效率间差异无统计学意义（P〉0.05）。结论：MDR1 C3435T位点的基因多态性与高血压患者的稳态血药浓度及降压疗效间无相关性。     

MDR1 C3435T基因多态性与胃溃疡患者治疗相关性分析

目的 分析MDR1 C3435T基因多态性与胃溃疡患者治疗的相关性.方法 回顾性分析2010年10月至2015年10月来我院就诊的胃溃疡患者共80名,其中Hp阳性患者47例,另选取80例健康体检者作为对照组,测定两组入选对象MDR1 C3435T基因多态性,比较不同基因型胃溃疡患者治疗后Hp阳性率和耐药率.结果 观察组(Hp阳性)患者3435TT基因型频率和T等位基因频率均明显高于观察组(Hp阴性)和对照组(P＜0.05);观察组(Hp阴性)患者3435TT基因型频率和T等位基因频率亦均明显高于对照组(P＜0.05).治疗后3435TT基因型患者Hp阳性率和耐药率均明显高于C3435T和CC3435基因型患者(P＜0.05).结论 MDR1 C3435T基因多态性与胃溃疡患者的治疗具有相关性,3435TT基因型患者较难根除Hp,耐药性较强.     

MDR1基因多态性对替米沙坦血药浓度和药动力学影响研究

目的:探讨健康志愿者和高血压患者的多药耐药基因(Multidrug resistance 1 gene,MDR1) C3435T基因多态性对替米沙坦血药浓度和药动学的影响.方法:采用聚合酶链反应(Polymerase chain reaction,PCR)和限制性内切片段多态性(Restriction fragment length polymorphism,RFLP)的方法对19名健康志愿者和61例高血压患者进行MDR1基因分型;使用HPLC-MS法测定志愿者单剂量口服40 mg替米沙坦48 h内血药浓度和高血压患者的稳态血药浓度.比较替米沙坦在不同基因型的健康志愿者单剂量药动学及高血压患者稳态血药浓度的差异.结果:在61例高血压患者中,MDRlCC型纯合子频率39.34％,TT型纯合子频率11.48％,CT型杂合子频率49.18％,C3435T发生率在健康人群和高血压患者之间没有明显的差异,C3435T的三个不同基因型志愿者Cmax、tmax、t1/2、AUC0-48、AUC0-∞和CL差异无统计学意义(P＞0.05).三个基因型高血压患者的稳态血药浓度差异无统计学意义(P＞0.05).结论:MDR1C3435T基因多态性对替米沙坦的血药浓度和药动学无影响.     

多药耐药基因MDR1 C3435T基因多态性对质子泵抑制剂三联方案根除幽门螺杆菌疗效影响的Meta分析

目的:系统评价多药耐药基因MDR1 C3435T基因多态性与质子泵抑制剂三联方案根除幽门螺杆菌疗效的关系,为临床提供循证参考。方法:计算机检索Pub Med、EMBase、中国生物医学文献数据库(CBM)、中国期刊全文数据库(CJFD)、万方数据库、中文科技期刊数据库(VIP),收集MDR1 C3435T基因多态性对质子泵抑制剂三联方案根除幽门螺杆菌感染疗效的临床研究,提取资料并按照STREGA声明评价质量,采用Rev Man 5.3统计软件进行Meta分析。结果:共纳入7项研究,合计1 019例患者。按照患者MDR1 C3435T基因型检测结果分为野生纯合子基因(CC)型组,突变杂合子基因(CT)型组与突变纯合子基因(TT)型组。Meta分析结果显示,MDR1 C3435T基因多态性中CC组、CT组与TT组患者幽门螺杆菌根除率比较,差异均无统计学意义[CC vs.CT:OR=0.99,95%CI(0.69,1.42),P=0.95;CC vs.TT:OR=1.44,95%CI(0.66,3.15),P=0.36;CT vs.TT:OR=1.54,95%CI(0.86,2.73),P=0.14];亚组分析发现,亚洲人群中CT组患者幽门螺杆菌根除率显著高于TT组,差异有统计学意义[OR=2.35,95%CI(1.53,3.62),P<0.001]。结论:MDR1 C3435T基因多态性基本不影响质子泵抑制剂三联方案根除幽门螺杆菌的疗效,但亚洲人群进行治疗时,参考基因检测结果有一定意义。     

中国朝鲜族人群MDR1基因多态性与环孢素A谷浓度的相关性研究

目的:研究中国朝鲜族肾移植术后患者服用环孢素A(CsA)的谷浓度与多药耐药基因(MDR1)C3435T多态性的相关性。方法:选择中国朝鲜族同种异体肾移植术后患者75例,采用聚合酶链反应(PCR)扩增MDR1C3435T基因,利用DNA限制性片段长度多态性(RFLP)方法对MDR1C3435T基因进行分型,结合口服CsA的谷浓度,判断二者是否存在关联。结果:75例患者中,C/C型31例(41.3%),C/T型37例(49.3%)和T/T型7例(9.3%)。C3435T基因多态性与CsA谷浓度差异无统计学意义(P>0.05)。结论:C3435T基因多态性可能不是影响中国朝鲜族肾移植术后患者CsA谷浓度的主要因素。     

影响他汀类药物降脂治疗的相关基因的多态性及其与高脂血症的关系

目的观察他汀类药物降脂治疗相关的基因多态性位点CYP3A4*1G、CYP3A 5*3、MDRl C3435T、SLC21A6 A388G、SLC21A6 T521C、CYP7Al A-204C及ABCG8 T400K在河南地区的分布及其与高脂血症的关系。方法采用聚合酶链反应-限制性片断长度多态性(PCR-RFLP)和等位基因特异性-聚合酶链式反应(AS-PCR)技术对400名高脂血症病人和320名正常对照者进行基因分型。结果等位基因SLC21A6 A388G、SLC21A6 T521C、CYP3A4*1G、CYP3A5*3、MDR1 C3435T、CYP7A1 A-204C及ABCG8 400K的分布频率在高脂血症病人中分别为72.1%、16.2%、27.9%、73.7%、39.9%、34.7%和12.8%,在正常对照组中分别为71.5%、16.1%、27.4%、74.5%、39.4%、33.3%和7.4%;ABCG8 400K等位基因携带者患高脂血症的风险显著增加(OR=1.870,CI:1.259-2.777,P=0.002)。结论CYP3A5*3、MDR1 C3435T、SLC21A6 A388G、SLC21A6 T521C和ABCG8 T400K基因多态性分布可能存在地区或种族差异,ABCG8 400K等位基因是高脂血症的高风险因素。     

中国汉族人孕烷X受体基因NR1I2的单核苷酸多态性

目的了解中国健康汉族人孕烷X受体基因NR1I2的单核苷酸多态性分布以明确种族差异。方法用PCR扩增后直接测序的方法,检测NR1I2基因2和4外显子及1,2,4和5内含子的单核苷酸突变。结果中国健康汉族人NR1I2基因2和4外显子均未发现已报道的单核苷酸突变,外显子1和内含子1,2,4和5检测到单核苷酸突变9种,分别为-24446C>A,-24381A>C,-24113G>A,252A>G,275A>G,4760G>A,7635G>A,7637C>T和7675C>T,等位基因频率分别为2.4%,20.8%,20.8%,33.3%,31.0%,68.5%,31.7%,1.6%和10.6%,其中7637C>T未见在任何文献和单核苷酸多态性数据库中报道,为新发现突变。结论中国健康汉族人NR1I2内含子1,2,4和5位置检测到9种单核苷酸突变,且突变频率较高,与白人和美国黑人比较,单核苷酸突变的发生位点和发生频率存在显著性差异。     

CYP3A5*3 and MDR-1 C3435T single nucleotide polymorphisms in six Chinese ethnic groups

The prevalent CYP3A5 *3 and the functional multi-drug resistance gene (MDR1) C3435T show marked interethnic variation among Orientals, Caucasians and Africans. This study aimed to investigate the distribution of CYP3A5*3 and MDR1 C3435T among Chinese ethnic groups. Genotypes of the CYP3A5*3 and MDR1 C3435T were determined in 839 unrelated healthy Chinese subjects by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assays. Frequencies (P < 0.05) of CYP3A5*3 variant alleles observed in Uygur Chinese, Kazakh Chinese and Tibetan Chinese (88.1%, 84.5% and 80.7%, respectively) were Significantly higher than those in Han Chinese, Wa Chinese and Bai Chinese (67.3%, 56.3% and 70.2%, respectively). Significantly higher 3435T variant frequencies (P < 0.05) were observed in Uygur Chinese (58.4%) and Kazakh Chinese (56.8%) compared with Han Chinese (44.2%), Tibetan Chinese (43.9%), Wa Chinese (45.8%) and Bai Chinese (44.2%). These results indicate that there were marked ethnic differences in the mutant frequencies of CYP3A5*3 and MDR1 C3435T among Chinese ethnic groups. Frequencies of those variants observed in Uygur Chinese, Kazakh Chinese, Tibetan Chinese, Wa Chinese and Bai Chinese wereintermediate between those seen in Han Chinese and African-American.     

Frequency of C3435T single nucleotide MDR1 genetic polymorphism in an Asian population: phenotypic-genotypic correlates

AIMS: To investigate the frequency of the single nucleotide polymorphism C3435T in exon 26 of the MDR1 gene in Asians and to determine the functional significance of this SNP with the clinical pharmacokinetics of oral cyclosporin (Neoral) in 10 stable heart transplant patients. METHODS: The MDR1 C3435T polymorphism was investigated in 290 healthy Asian subjects (98 Chinese, 99 Malays and 93 Indians). We also compared the MDR1 polymorphism between the Asian population studied here and the published data on Africans and Caucasians. The clinical relevance of this SNP on oral bioavailability of a known P-gp substrate, cyclosporin, was assessed in 10 stable Chinese heart transplant patients. RESULTS: The homozygous TT genotype was observed in 32%, 28% and 43% of Chinese, Malays and Indians. The homozygous CC genotype was found in 25% of Chinese and Malays compared with 18% of Indians. The Indians had a lower frequency of the C allele [0.38 (0.31-0.45)] compared with the Chinese [0.46 (0.39-0.53)] and Malays [0.48 (0.42-0.55)]. Chi-squared test showed that the distribution of allele frequencies between the Malays and Indians differed significantly (P = 0.04). In this Asian population, the overall distribution of genotypes (CC, CT and TT) and allele frequencies were significantly different from those in Africans (P < 0.001). The results were also significant when the Chinese, Malays and Indians were compared separately with the African group (P < 0.001). Compared with the Caucasian data, the overall distribution of genotype and allele frequencies in the Asian population were also significantly different (P < or = 0.05). However, when each Asian ethnic group was compared separately with the Caucasians, only the Indians were found to be significantly different (P < or = 0.004). Genotypic-phenotypic correlations of this SNP were assessed in 10 stable Chinese heart transplant patients. The median AUC(0,4 h) was 11% lower in patients with CC genotype compared with subjects with TT genotype. However, the interpatient variability in AUC(0,4 h) was high in patients, especially in those with CC genotype. CONCLUSIONS: The distribution of the SNP C3435T in exon 26 in the Chinese and Malay population was found to be similar to the Caucasians whereas the Indians were different. The Asian population also differed significantly from the African and Caucasian population in the distribution of the C3435T SNP. The low frequency of the T allele in the Indian population implies lower expression of P-gp and may have important therapeutic and prognostic implications for use of P-gp dependent drugs in individuals of Indian origin.     

Allele and genotype frequency of MDR1 C3435T in Tamilian population

The allele and genotype frequencies of MDR1 C3435T polymorphism were determined in 185 unrelated healthy Tamilians. The genomic DNA was extracted from peripheral leucocytes using phenol chloroform method and genotyped by PCR-RFLP method. The frequencies of MDR1 C3435 and T3435 alleles in Tamilian population were 0.46 and 0.54 respectively. The distribution of T3435 in this population was found to be greater than Africans and almost similar to Caucasians and Orientals. The distribution of CC, CT and TT genotypes was 0.18, 0.56 and 0.26 respectively. The frequency distribution of the CC genotype was lower in them when compared with Chinese and Africans whereas CT genotype was higher in comparison with all the major ethnic groups.     

Genotype and allele frequencies of C3435T polymorphism of the MDR1 gene in various Jewish populations of Israel

The human multidrug-resistant gene (MDR1) encodes for P-glycoprotein (P-gp), which is a membrane-bound efflux-transporter conferring resistance to a number of natural cytotoxic drugs and potentially toxic xenobiotics. The wobble C3435T polymorphism at exon 26 was associated with different expression levels of the MDR1 gene and substrate uptake. Differences in allele frequencies of the C3435T polymorphism have previously been demonstrated between racial groups. In this study, 500 individuals from 5 Jewish populations of Israel (Ashkenazi, Yemenite, North African, Mediterranean, Near-Eastern) were examined for C3435T polymorphism using a PCR-RFLP-based technique to calculate genotype and allele frequencies. Frequencies of the C allele were quite similar among the Ashkenazi (0.65), Yemenite (0.645), and North-African (0.615) Jewish populations. However, the frequency of this allele was slightly lower among Mediterranean Jews (0.58) and significantly lower among Near-Eastern Jews (0.445). The frequency of the C allele among Near-Eastern Jews is, therefore, significantly different from those of all other tested Jewish populations. In comparison to previously studied non-Jewish populations, the frequency of this allele among Near-Eastern Jews is different from that in West Africans (0.91) but is similar to that in whites (0.497). However, the C allele frequencies among the other 4 Jewish populations are significantly lower than that found among West Africans and significantly higher than among non-Jewish whites. These data may have important therapeutic and prognostic implication for P-gp-related drug dosage recommendation in Jewish populations.     

MDR1基因多态性对口服环孢素A药代动力学的影响

目的非线性混合效应模型(NONMEM)考察中国健康人多药耐药基因(MDR1)中26外显子的C3435T多态性与环孢素A (CsA)药代动力学特性间的关系。方法HPLC法测定20名健康男性单次口服CsA微乳溶液制剂500 mg后24 h内不同时间点的药物浓度。MDR1的基因多态性测定采用DNA限制性片段长度多态性法，并用基因测序法验证。数据处理与模型拟合采用NONMEM法。结果中国健康人中含MDR1 C3435T CC或CT型的相对生物利用度较TT型高40%。结论MDR1中C3435T多态性是个体间CsA相对生物利用度差异的影响因素。     

The effect of CYP3A5 and MDR1 polymorphic expression on cyclosporine oral disposition in renal transplant patients

Variability in CYP3A (CYP3A4/5) and P-glycoprotein (human MDR1 gene product) activity underlies interindividual differences in oral cyclosporine (CsA) bioavailability. Racial differences in polymorphic expression of CYP3A5 and MDR1 may explain observed interracial variability in oral bioavailability. Our objective was to evaluate the effect of CYP3A5 and MDR1 polymorphic expression on CsA oral disposition. Steady-state plasma concentration profiles (n = 19) were sampled in renal transplant recipients receiving concentration-adjusted CsA maintenance therapy. CsA plasma concentrations were measured by fluorescence polarization immunoassay. CYP3A5 and MDR1 genotypes were determined by real-time polymerase chain reaction. Noncompartmental pharmacokinetic analysis and nonlinear mixed-effects modeling (NONMEM) were performed to assess the effect of genotype on CsA pharmacokinetics. MDR1 C3435T genotype was identified as the best predictor of CsA systemic exposure. CsA oral clearance was significantly higher in subjects who carried at least one 3435T allele compared to homozygous wild-type individuals (40.0 +/- 2.2 vs. 26.4 +/- 3.1 L/h, p = 0.007). MDR1 C3435T genotype accounted for 43% of the interindividual variability of CsA oral clearance in the study population after accounting for interoccasion variability. The authors were unable to independently assess whether CYP3A5 correlated with any CsA pharmacokinetic parameter since all CYP3A5 nonexpressors were also 3435T allele carriers. MDR1 3435T allele carriers have enhanced oral clearance compared to individuals with the CC genotype. The frequency of the 3435T allele is lower in African Americans compared to Caucasians. Thus, the MDR1 C3435T genotype offers a potential mechanistic basis to explain interracial differences in CsA oral bioavailability. Further studies are needed to explore the relationship between CYP3A5 and MDR1 genotype and phenotype.     

MDR1 genetic polymorphisms and comparison of MDR1 haplotype profiles in Korean and Vietnamese populations

Two representative genetic variants of the MDR1 gene, 3435C>T and 2677G>T/A, show wide interethnic differences in its genetic polymorphism. In this study, the authors evaluated the genetic polymorphisms of MDR1 and directly compared MDR1 haplotype profiles of the Korean and Vietnamese populations. The 3435C>T and 2677G>T/A variations were analyzed in 632 Koreans and 142 Vietnamese using pyrosequencing. The allelic frequencies of 3435C>T did not significantly differ between the Korean (39.3%) and Vietnamese (36.6%) groups. However, the frequencies of mutant alleles at 2677 locus (T or A allele) showed a significant difference between Koreans (56.2%) and Vietnamese (41.9%), as the frequency of 2677A allele in the Korean subjects (17.1%) was much higher than that of the Vietnamese subjects (6.3%). Linkage analysis revealed that 2677A allele is closely linked to 3435C allele. The frequency of 2677A-3435C haplotype in Koreans was 15.4%, which was significantly higher than that found in Vietnamese subjects (6.3%). In conclusion, the frequencies of MDR1 variants and haplotype profiles showed significant differences between the Korean and Vietnamese populations, especially with respect to the 2677G>T/A variants. Because the 2677A allele was recently found to be functional in vivo and was detected at a high frequency in Koreans, the genotyping of this variant is necessary for pharmacogenetic studies of MDR1 in this population. In addition, by virtue of strong linkage disequilibrium, 2677A-3435C haplotype may help improve the predictability of MDR1 genetic polymorphism for MDR1 functional changes.     

C3435T polymorphism of the ABCB1/MDR1 gene encoding P-glycoprotein in patients with inflammatory bowel disease in a Polish population

BackgroundInflammatory bowel disease (IBD) belongs to the group of chronic diseases of the gastrointestinal tract, prevalence of which is increasing in the Polish population. The two main clinical types of IBD are ulcerative colitis (UC) and Crohn’s disease (CD). The expression level of the ABCB1/MDR1 gene which encodes P-glycoprotein seems to be of great prognostic relevance while evaluating patients’ susceptibility to UC or CD. One of the most significant ABCB1/MDR1 gene mutations is the C3435T polymorphism. A decreased expression of the ABCB1/MDR1 gene and lower P-glycoprotein activity has been associated with the 3435T variant. The aim of the study was to evaluate the C3435T polymorphism in the IBD patients and to investigate a possible correlation with disease susceptibility.MethodsThe study was performed on 108 patients with IBD and on 137 healthy individuals. All the participants were of Caucasian origin and came from central Poland. The C3435T polymorphism was analyzed by using the PCR-RFLP method.ResultsOur results showed that ORs for IBD development (including UC and CD) were elevated in individuals both with the 3435CC genotype and the 3435C allele. The differences in genotype and allele frequencies were not significant.ConclusionsThe C3435T polymorphism of the ABCB1/MDR1 gene is not a risk factor for IBD, including UC and CD, in the population coming from central Poland.