核苷类药与慢性HBV感染者病毒P基因准种及变异特点的关系

目的观察核苷类药治疗不同时间段慢性HBV感染患者血清乙肝病毒聚合酶(HBV P)基因准种变化及变异特点。方法运用焦磷酸测序仪器配套的软件Assay Design SW在目的区域两端保守区域设计PCR引物及测序引物,采用套式PCR方法检测血清中HBV DNA,按照Pyro-Mark ID遗传分析系统用SNP模式进行PCR产物(HBV P基因相关位点)的焦磷酸测序和突变频率检测。108例慢性HBV感染患者中用药史明确者同期测定HBV DNA、HBV标志物、ALT。结果108例患者中,61例发生变异,变异模式以经典突变L180M、M204V/I、A181V/T、N236T突变为主,有少量V173L、S202G、T184G突变;其中40例用药史明确患者中,18例发生变异,发生变异者耐药突变型在样本中所占比例为20%-100%,HBV P基因变异可以在HBV DNA、ALT发生突变前、中、后检出。结论焦磷酸测序可以快速检测HBV P基因变异;变异株突变频率变化可初步反映HBVP基因准种异质性;HBV P基因变异模式、突变频率与核苷类药物敏感性密切相关。     

脂蛋白脂肪酶基因突变的研究

目的：筛查国人脂蛋白脂肪酶(LPL)基因的突变，并探讨其与高甘油三酯血症的关系。方法：对高甘油三酯血症组(48例)和正常甘油三酯对照组(121例)的各扩增片段进行分析，电泳图谱异常者进行PCR产物测序。对于频率较高的多态性位点，引入限制性核酸内切酶位点利用PCR-RFLP进行鉴定。结果：在高甘油三酯血症人群中，检出2例内含子3受位剪接点上游6bp的C→T转换的突变杂合子，1例外显子5Pm^207→Leu突变杂合子，在全部样品中检出1例Ser^447→stop突变纯合子，50例Ser^447→stop杂合子。结论：天津地区人群中存在着LPL基因突变，除Ser^447→stop外，内含子3和外显子5的突变多与高甘油三酯血症相关，可能是高甘油三酯血症的遗传易感因子。     

苯丙酮尿症患者突变基因的检测

目的 检测苯丙酮尿症(phenyl—ketonuria,简称PKU)患者的基因突变类型。方法采用PCR-SSCP(聚合酶链反应单链构象多态)银染和PCR-ASO(聚合酶链反应等位基因特异性寡核苷酸)探针杂交,分别检测了8个PKU家庭中10名患者和6名双亲。PCR—SSCP银染应用了3对引物,外显子7、11、12。PCR-ASO探针杂交应用了外显子7、10、11、12、4对探针。结果 王氏家系姐弟俩(表1中编号7,10)通过PCR-SSCP方法发现E_7区域有异常电泳带,经PCR-ASO方法证实他们和附图编号8均为苯丙氨酸羟化酶E7R243Q位点的纯合子突变;沈氏家系姐妹俩通过PCR-ASO法检出E12R413P位点为纯合子突变,另一例PKU患者为E12R413P位点的杂合子。结论 上述突变位点为PKU患者的产前基因诊断提供了依据。     

13例Wilson病患者基因8号外显子778密码子碱基突变的SSCP及酶切分析

目的 寻找山东籍Wilson病患者WND基因突变热点,以便易于用SSCP及酶切分析方法检出。使无先证者及独生子女家系易于作出基因诊断,同时可用于杂合子筛查。方法 PCR扩增WND基因8号外显子778密码子区域,SSCP检洲点突变,用MSPI内切酶进一步验证G-T突变的正确性。结果 13例Wilson患者,检出778密码子G-T纯合突变2例,杂舍突变7例,未突变4例,共计26条染色体,突变染色体11条,总染色体突变率为42.3％。结论 WND基因8号外显子,778密码子G-T突变是山东WD患者的一个突变热点。SSCP和酶切分析是诊断此位点突变的便捷方法,可用于WD患者及杂合子检出。     

地中海贫血患儿及其父母基因型检测与出生前缺陷干预

目的检测地中海贫血患儿厘其父母基因型，了解其遗传规律，提倡产前检测地中海贫血基因，同时对重症地中海贫血胎儿进行出生前缺陷干预。方法收集39例地中海贫血患儿及其父母样品，提取DNA,采用Gap-PCR、寡核苷酸探针反向斑点杂交法对α-、β-地中海贫血突变基因类型进行分析。结果在39份样品中，其中14例小地中海贫血患儿地中海贫血基因型全为缺失型；25例β-地中海贫血患儿基因型以CD41／42位点突变杂合子和CD41／42与IVSⅠ-Ⅱ-654位点突变双重杂合子为主，其父母均为杂合子。结论α-地中海贫血患儿地中海贫血基因缺失型和β-地中海贫血患儿基因突变符合遗传规则，产前基因诊断是控制地中海贫血患儿出生及疾病遗传的有效手段。     

高分辨率熔解曲线法在GLP1R基因多态性位点rs3765467检测中的应用

目的:建立检测肠促胰岛素样肽-1受体(GLP1R)基因已知突变位点rs3765467(NT_007592.16的第39 065 819位)的方法,并评价其准确性与实用性。方法:收集我院体检中心2015年10月-2016年2月72例健康体检者的外周静脉血样本,采用柱提法提取其全血DNA,经降落聚合酶链反应扩增后,采用高分辨率熔解曲线(HRM)法对产物进行分析;同时选取其中38例受试样本进行双脱氧链终止法(Sanger测序法)测序验证,比较2种方法的结果。结果:突变扫描结果显示,扩增片段中存在39 065 817和39 065 819两个多态性位点。HRM法只检测出了4种基因型[GCG/GCG、GCA/GCG或ACG/GCG、GCA/GCA或ACG/ACG、A(G)CA(G)];而Sanger测序法共检测出6种基因型[GCG/GCG、ACG/GCG、ACG/ACG、A(G)CA(G)、GCA/GCG、GCA/GCA]。结论:HRM法可区分GCG/GCG和A(G)CA(G)基因型,但无法区分GCA/GCG与ACG/GCG杂合突变、GCA/GCA与ACG/ACG纯合突变。该方法并不适用于多个邻近位点的单核苷酸多态性检测。在进行单核苷酸突变检测时,应对序列进行综合分析后再选取经济、简便的方法。     

原发性高胆固醇血症家系成员载脂蛋白B-100基因突变的筛查

目的　筛查原发性高胆固醇血症患者载脂蛋白B 1 0 0基因可能存在的突变体。方法　通过改变参与巢式聚合酶链反应 (PCR)反应的一个寡核苷酸引入酶切入点法检测载脂蛋白B 1 0 0基因发生R350 0Q的突变情况。在其附近可能存在的突变位点用单链构象多态性分析 (SSCP)和DNA测序分析法进行筛查。结果　 34例样本均未发现载脂蛋白B 1 0 0基因突变位点。结论　载脂蛋白B 1 0 0基因突变可能不是引起原发性高胆固醇血症的主要原因。     

PVRL2的SNPs与非综合征性唇腭裂相关性分析

目的 探讨核心家庭中脊髓灰质炎病毒受体相关2(PVRL2)基因SNP位点突变与非综合征性唇腭裂(NSCL/P)的关系.方法 用基因芯片技术检测50例华东地区核心家庭的PVRL2基因SNP位点(rs2075642)的突变情况.设计病例对照和核心家庭对照,用医学统计学方法,比较突变位点在患儿与正常儿童中的分布情况,比较患儿组与父母组的基因型和等位基因频率,并对核心家庭的数据进行单倍型相对风险分析(HTRR),对含杂合子父母的核心家庭进行传递不平衡检验(TDT).结果 PVRL2的rs2075642位点突变在患儿与正常儿童中的分布差异有统计学意义,患儿与其父母各位点基因型和等位基因分布差异无统计学意义(P>0.05),HTRR结果有统计学意义,TDT结果无统计学意义.结论 PVRL2的rs2075642位点突变可能与中国华东人群非综合征性唇腭裂存在相关性.     

遗传性高铁血红蛋白一家系的基因诊断

目的 检测Ⅰ型遗传性高铁血红蛋白血症(HM)先证者(L72P,长乐)家系成员的细胞色素b5还原酶(b5R)基因的突变。方法 PCR方法扩增正常人和HM先证者之兄、父、母的b5R基因组DNA片段(含第3和第4外显子);用限制性内切酶Apa Ⅰ分析扩增产物。结果PCR扩增产物用Apa Ⅰ酶切后,正常人为649和471 bp;先证者之兄为649、440和31bp,表明存在b5R基因第72密码子纯合子突变:其父、母均为649、471、440和31bp,表明存在b5R基因第72密码子杂合子突变。结论PCR结合Apa Ⅰ内切酶分析可用于b5R基因第72密码子突变的检测;PCR-RFLP方法是检测人群中b5R基因杂合子突变的简捷有效的方法。     

血管紧张素Ⅱ受体基因多态性与醛固酮腺瘤发病风险的相关性

目的 探讨血管紧张素Ⅱ 1型受体及2型受体基因(AT1R、AT2R)多态性与中国汉族人群肾上腺醛固酮腺瘤(APA)发病风险的相关性.方法 提取148例APA组织DNA及192例正常人群外周血DNA;采用MGB-Taqman探针法对AT1R基因(rs5182、rs5186)和AT2R基因(rs5194、rs1403543) 4个SNP位点进行基因型检测.SNPassoc 1.5-3软件分析Hardy-Weinberg平衡以及AT1R、AT2R基因多态性与APA发病危险的关联性.结果 4个位点基因型分布均符合Hardy-Weinberg平衡(P均＞0.05).APA组AT2R基因rs5194位点A等位基因频率(0.49)要高于正常人群组(0.35)(x2=12.08,P==0.001).以rs5194纯合子基因型GG为参照,纯合子基因型AA和杂合子基因型GA的APA发病风险均增高(OR=2.66,95％ CI=1.45-4.87和OR=1.67,95％ CI=1.02-2.74).rs5194位点多态性在显性模型、隐性模型以及加性模型中均与APA发病相关联(OR=1.94,95％CI=1.23-3.06,P=0.003; OR=2.01,95％ CI=1.17-3.45,P=0.01; OR=1.64,95％CI=1.21-2.20,P=0.001).结论 AT2R基因rs5194位点多态性和APA发病相关联,对该SNP位点的检测可能可以对预测APA的发病危险提供有用的遗传信息.     

突变体富集PCR法检测非小细胞肺癌病理组织EGFR基因突变

目的：建立突变体富集PCR法检测非小细胞肺癌病理组织中的EGFR基因突变。方法：选取55例细支气管肺泡癌和59例非小细胞肺癌病理组织蜡块，提取基因组DNA，采用不同的突变体富集PCR法（PCR-PAGE和PCR-RLFP）检测EGFR基因常见的19和21外显予突变，并经过直接测序验证。结果：在59例非小细胞肺癌中共检测出EGFR基因突变22例,突变率为37．3％（22／59）。55例细支气管肺泡癌中共检测出24例基因突变，突变率为43．6％（24／55）。经直接测序验证，EGFR19外显予有3种类型缺失突变。EGFR21外显予的错义突变为L858R。结论：突变体富集PCR法准确、快速、经济，便于临床筛查非小细胞肺癌病理组织中的EGFR基因突变。     

Detection of EGFR Somatic Mutations in Non-Small Cell Lung Cancer (NSCLC) Using a Novel Mutant-Enriched Liquidchip (MEL) Technology

We have developed and standardized a novel technology, mutant-enriched liquidchip (MEL), for clinical detection of EGFR mutations. The MEL integrates a mutant-enriched PCR procedure with liquidchip technology for detections of EGFR exon 19 deletions and L858R mutation on both formalin-fixed and paraffin-embedded (FFPE) slides and plasma samples from patients with non-small cell lung cancer (NSCLC). The detection sensitivity was 0.1% of mutant DNA in the presence of its wild-type DNA. The cross-reaction rate was lower than 5%. To evaluate the MEL platform, the EGFR mutation status of 59 patients with advanced NSCLC treated with EGFRTKIs (Tyrosine Kinase Inhibitors) were tested on their FFPE samples. EGFR exon 19 deletions and L858R were detected in 21 patients (21/59) and 76.2% (16/21) of them had partial response to the EGFR-TKIs, while by sequencing method, only 4 (4/59) mutations were detected. Plasma samples from 627 patients with various stages of NSCLC were examined with the MEL and 22% of EGFR exon 19 deletions and L858R were detected. Furthermore, in patients with advanced disease there are more mutations detected in plasma samples than in patients with less advanced disease. In conclusion, the MEL is a sensitive, stable, and robust technology for detecting EGFR DNA mutations from both FFPE and plasma samples from patients with NSCLC and is now routinely used for clinical diagnosis.     

大肠癌中EGFR基因单核苷酸多态性及EGFR表达的分析

目的 探讨表皮生长因子受体(epidermal growth factor receptor,EGFR)基因外显子13G64A单核苷酸多态性及EGFR蛋白表达与大肠癌的相关性.方法 应用PCR - RFLP法结合DNA测序法对72例大肠癌患者外周血DNA中EGFR基因的外显子13G64A单核苷酸多态性位点的等位基因进行...     

Genetic variations and haplotypes of UGT1A4 in a Japanese population

Nineteen genetic variations, including 11 novel ones, were found in exon 1 and its flanking region of the UDP-glucuronosyltransferase (UGT) 1A4 gene from 256 Japanese subjects, consisting of 60 healthy volunteers, 88 cancer patients and 108 arrhythmic patients. These variations include -217T>G and -36G>A in the 5'-flanking region, 30G>A (P10P), 127delA (43fsX22; frame-shift from codon 43 resulting in the termination at the 22nd codon, codon 65), 175delG (59fsX6), 271C>T (R91C), 325A>G (R109G), and 357T>C (N119N) in exon 1, and IVS1+1G>T, IVS1+98A>G and IVS1+101G>T in the following intron. Among them, 127delA and 175delG can confer early termination of translation, resulting in an immature protein that probably lacks enzymatic activity. Variation IVS1+1G>T is located at a splice donor site and thus may lead to aberrant splicing. Since we did not find any significant differences in the frequencies of all the variations among the three subject groups, the data were analyzed as one group. The allele frequencies of the novel variations were 0.006 for IVS1+101G>T, 0.004 for 30G>A (P10P) and 357T>C (N119N), and 0.002 for the 8 other variations. In addition, the two known nonsynonymous single nucleotide polymorphisms (SNPs), 31C>T (R11W) and 142T>G (L48V), were found at 0.012 and 0.129 frequencies, respectively. The SNP 70C>A (P24T), mostly linked with 142T>G (L48V) in German Caucasians, was not detected in this study. Sixteen haplotypes were identified or inferred, and some haplotypes were confirmed by cloning and sequencing. It was shown that most of 142T>G (L48V) was linked with -219C>T, -163G>A, 448T>C (L150L), 804G>A (P268P), and IVS1+43C>T, comprising haplotype *3a; haplotype *4a harbors 31C>T (R11W); 127delA (43fsX22) and 142T>G (L48V) were linked (haplotype *5a); 175delG (59fsX6) was linked with 325A>G (R109G) (*6a haplotype); and -219C>T, -163G>A, 142T>G (L48V), 271C>T (R91C), 448T>C (L150L), 804G>A (P268P), and IVS1+43C>T comprised haplotype *7a. Our results provide fundamental and useful information for genotyping UGT1A4 in the Japanese and probably Asian populations.     

湖南地区238 例非小细胞肺癌EGFR 基因突变状态分析

目的：评价湖南地区非小细胞肺癌患者EGFR基因突变状态及其与临床特征之间的关系。方法收集2012年1月至2013年6月中南大学湘雅医学院附属肿瘤医院手术切除的非小细胞肺癌石蜡包埋组织238例,采用PCR扩增结合直接基因测序的方法,对组织DNA中EGFR基因第18-21外显子突变进行检测。结果在238例非小细胞肺癌中,EGFR突变的检出率为35.3％（84/238）。其中,第18、19、20、21号外显子突变占总突变的比例分别为2.4％（2/84）、67.9％（57/84）、3.6％（3/84）、26.2％（22/84）。19号外显子的突变均为第746-753密码子的碱基缺失,以Del E746-A750为主;21号外显子突变类型以L858R为主。女性EGFR基因的突变率显著高于男性,不吸烟者显著高于吸烟者（P〈0.05）。而EGFR基因的突变率与非小细胞肺癌患者的年龄、临床分期和淋巴结转移均无相关性（P〉0.05）。结论湖南地区的非小细胞肺癌EGFR基因突变以19、21外显子为主,且19外显子的突变率高于21外显子,多见于女性、腺癌、不吸烟患者。     

EGFR基因突变直接测序检测方法的建立

目的 建立一种适用于临床表皮生长因子受体（EGFR）基因直接测序突变检测方法.方法 以EGFR基因突变热点19、21外显子为突变检测靶位点设计特异性扩增、测序引物,以已知19、21外显子野生型、突变型样品分别做为阴、阳性对照品,建立EGFR基因突变直接测序检测方法,进行方法学评估.结果 成功建立了EGFR基因突变直接测序检测方法,该方法检测灵敏度为4.7 ng/μl,重复性良好.检测30例结非小细胞肺癌样品,突变率为26.7％.结论 本研究建立了可用于临床样品检测的EGFR基因突变直接测序检测方法.     

Chronicles of EGFR Tyrosine Kinase Inhibitors: Targeting EGFR C797S Containing Triple Mutations

Epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase widely expressed in many cancers such as non-small cell lung cancer (NSCLC), pancreatic cancer, breast cancer, and head and neck cancer. Mutations such as L858R in exon 21, exon 19 truncation (Del19), exon 20 insertions, and others are responsible for aberrant activation of EGFR in NSCLC. First-generation EGFR tyrosine kinase inhibitors (TKIs) such as gefitinib and erlotinib have clinical benefits for EGFR-sensitive (L858R and Del19) NSCLC patients. However, after 10-12 months of treatment with these inhibitors, a secondary T790M mutation at the gatekeeper position in the kinase domain of EGFR was identified, which limited the clinical benefits. Second-generation EGFR irreversible inhibitors (afatinib and dacomitinib) were developed to overcome this T790M mutation. However, their lack of selectivity toward wild-type EGFR compromised their clinical benefits due to serious adverse events. Recently developed third-generation irreversible EGFR TKIs (osimertinib and lazertinib) are selective toward driving mutations and the T790M mutation, while sparing wild-type EGFR activity. The latest studies have concluded that their efficacy was also compromised by additional acquired mutations, including C797S, the key residue cysteine that forms covalent bonds with irreversible inhibitors. Because second- and third-generation EGFR TKIs are irreversible inhibitors, they are not effective against C797S containing EGFR triple mutations (Del19/T790M/C797S and L858R/T790M/C797S). Therefore, there is an urgent unmet medical need to develop next-generation EGFR TKIs that selectively inhibit EGFR triple mutations via a non-irreversible mechanism.     

The frequency and distribution of thiopurine methyltransferase alleles in Caucasian and Asian populations

Thiopurine methyltransferase metabolizes 6-mercaptopurine, thioguanine and azathioprine, thereby regulating cytotoxicity and clinical response to these thiopurine drugs. In healthy Caucasian populations, 89-94% of individuals have high thiopurine methyltransferase activity, 6-11% intermediate and 0.3% low, resulting from genetic polymorphism. Four variant thiopurine methyltransferase alleles were detected in over 80% of individuals with low or intermediate thiopurine methyltransferase activity. The wild-type allele is defined as TPMT*1 and the mutant alleles are TPMT*2 (G238C), TPMT*3A (G460A and A719G), TPMT*3B (G460A) and TPMT*3B (A719G). The frequency of these alleles in different ethnic groups is not well defined. In this study, DNA from 199 British Caucasian, 99 British South West Asian and 192 Chinese individuals was analysed for the presence of these variant alleles using polymerase chain reaction-restriction fragment length polymorphism and allele-specific polymerase chain reaction based assays. The frequency of individuals with a variant thiopurine methyltransferase genotype was: Caucasians 10.1% (20/199), South West Asians 2.0% (2/99) and Chinese 4.7% (9/192). Two TPMT*2 heterozygotes were identified in the Caucasian population, but this allele was not found in the two Asian populations. TPMT*3A was the only mutant allele found in the South West Asians (two heterozygotes). This was also the most common mutant allele in the Caucasians (16 heterozygotes and one homozygote) but was not found in the Chinese. All mutant alleles identified in the Chinese population were TPMT*3C (nine heterozygotes). This allele was found at a low frequency in the Caucasians (one heterozygote). This suggests that A719G is the oldest mutation, with G460A being acquired later to form the TPMT*3A allele in the Caucasian and South West Asian populations. TPMT*2 appears to be a more recent allele, which has only been detected in Caucasians to date. These ethnic differences may be important in the clinical use of thiopurine drugs.     

Somatic mutations in epidermal growth factor receptor underlying complete responsiveness to gefitinib in a Taiwanese female patient with metastatic adenocarcinoma of lung

A 61-year-old never-smoker female suffered from adenocarcinoma of the lung with chest wall invasion and peri-adrenal lymph node metastases. After palliative resection of all clinically detectable primary and metastatic adenocarcinoma, she received cisplatin and gemcitabine combination chemotherapy for a total of 3 cycles. New metastatic lesions were found in spleen and para-aortic lymph nodes. Her tumor tissue was subjected to mutation analysis for epidermal growth factor receptor (EGFR) and had been shown to have a T-->G missense mutation in nucleotide 2819 of EGFR full-length cDNA (accession no. NM_005228.3), within exon 21 of the EGFR gene, resulting in amino acid substitutions from leucine to arginine at codon 858 (L858R) as expected. She received oral gefitinib 250 mg/day after mutation analysis. She had a very good tumor response with more than 90% tumor reduction shown by abdominal computed tomographic scan, normalization of previously elevated carcinoembryonic antigen level, and complete resolution of previous uptake signals in spleen and para-aortic lymph nodes shown by positron emission tomographic scan. She has been kept in clinical complete remission for 11+ months after the initiation of gefitinib treatment. Our patient supports the proposition that somatic mutation L858R in exon 21 of the EGFR gene accounts for complete responsiveness to gefitinib in a Taiwanese female patient with metastatic adenocarcinoma of lung.