中国福建遗传性乳腺癌BRCAl基因突变分析

目的 研究福建遗传性乳腺癌患者BRCAI基因突变位点及携带情况.方法 对20例遗传性乳腺癌患者血液标本进行检测,对其BRCA1基因第11号外显子全序列进行DNA测序.结果 20例标本中检出5患者存在共计9种BRCA1基因突变,其中3个为新发现住点(错义突变1159T>C,4071A>C;同义突变4122C>T);其它6个已报道位点中2个(2201C>T,2430T>C)为同义突变,其余4个(2685T>C,2731C>T,3232A>G,3667A>G)属错义突变,本研究中BRCA1突变率为25%.结论 福建遗传性乳腺癌患者BRCA1基因突变具有地域性特征,开展BRCA1基因突变检测有助于本地区女性患癌风险评估和早期诊断.     

新疆地区维吾尔族乳腺癌BRCA1基因突变分析

目的研究新疆地区维吾尔族乳腺癌患者BRCA1基因突变情况及突变位置。方法选取70例维吾尔族乳腺癌根治标本,对照组为32例维汉族乳腺良性病变（纤维腺病及纤维腺瘤）及乳腺癌旁非癌组织;应用PCR-单链构象多态性和DNA序列测定的方法检测BRCA1基因突变。结果（1）70例维吾尔族乳腺癌中发现9例BRCA1突变的12个新位点。（2）70例维吾尔族乳腺癌BRCA1的突变率为12.86%（9/70）,22例维吾尔族早发性乳腺癌（≤35岁）BRCA1突变率为31.82%（7/22）。维吾尔族早发性乳腺癌BRCA1突变率（7/22）高于维吾尔族晚发性乳腺癌（2/48）,差异有统计学意义（χ^2=10.295,P〈0.01）。（3）70例维吾尔族乳腺癌中发现9例BRCA1基因核苷酸多态性位点,其中8例多态性位点均为3232A〉G。（4）2例双侧乳腺癌中均检测出BRCA1基因的突变。结论BRCA1突变可能与新疆维吾尔族乳腺癌尤其是维吾尔族早发性乳腺癌及双侧乳腺癌的发生密切相关。     

中国上海家族性乳腺癌BRCA1和BRCA2基因的突变

目的研究上海地区家族性乳腺癌中BRCA1／BRCA2基因的突变位点及携带情况。方法研究对象来自35个汉族家族性乳腺癌家系，家系中至少有一个一级亲属乳腺癌患病史。共35例患者，其中13例发病年龄≤加岁。由静脉血提取基因组DNA，对BRCA1／BRCA2基因的全部编码序列进行扩增。扩增产物突变分析先由变性高效液相色谱分析进行筛查，之后进行DNA直接测序证实。结果在BRCA1基因中发现有4个突变位点，其中2个为新发现位点——拼接点突变（IVS17-1G〉T；IVS21＋1G〉C）；另两个为已报道的致病突变位点——移码突变（1100delAT；5640delA）。BRCA2基因的1个致病突变位点位于11号外显子上，为移码突变（5802delAATT）。另外，共发现有12个新的单核苷重复多态位点，都未引起氨基酸编码改变；其中，8个在BRCA1基因上，4个在BRCA2基因上。在家族性乳腺癌中，BRCA1突变频率（11．4％）高于BRCA2基因（2．9％）。结论新发现的2个BRCA1基因的拼接点突变可能是中国上海人群家族性乳腺癌的特有突变位点；在我国上海地区人群中，BRCA1基因突变起着比BRCA2基因更大的作用；该研究丰富了中国人群中BRCA基因的突变谱，并为未来的临床基因检测提供了筛查模式。     

五例戊二酸血症I型患者GCDH基因突变的分子诊断CSCD

目的探讨5例戊二酸血症I型（glutaric acidemiatype I,GA—I）患者的GCDH基因突变情况,为临床诊治提供参考依据。方法应用Sanger测序法对泉州地区5例GA—I患者GcDH基因的所有外显子及侧翼内含子进行测序,并对测得序列进行分析,以寻找可能的致病突变位点。结果5例患者均检测到GCDH基因突变,共检测到4种突变位点,包括2种错义突变[c．532G〉A（P．G178R）、C．533G〉A（P．G178E）]和2种移码突变Ee．106—107delAC（P．Q37fs＊5）、C．1244—2A〉c]。其中,c．1244—2A〉C突变频率最高～C106—107delAC为未见报道的新突变,MutationTaster软件预测其为致病性突变。结论本研究分析了5例戊二酸血症I型患者的GCDH基因突变情况,从基因水平上证实了临床诊断,发现1个新的GCDH基因突变位点,丰富了GCDH基因的突变谱。     

吕梁地区遗传性耳聋GJB2基因和mtDNA1555位点的突变筛查

目的通过对吕梁地区96例耳聋患者的GJB2基因和mtDNA1555位点突变筛查,了解该地区的基因突变情况及热点突变位点。方法采用聚合酶链式反应（PCR）扩增96例标本的GJB2基因和mtDNA1555位点所在区段,产物酶切、测序分析。结果96例标本共计检出10个GJB2基因突变位点,与编码连接蛋白的非综合征耳聋突变数据库（http：／／davinci．crg．es／deafness／index．php？seccion=mut_db＆db=nonsynd）比对,8个位点已见报道,其中包括4个多肽位点c．79G〉A、C．341A〉G、c．608T〉C、C．457G〉A和4个致病位点C．235delC、e．109G〉A、c．176-C．191dell6和C．299-c．300delAT,其中,c．235delC是主要突变方式,携带率为6．25％（12／192）;2个位点（c．IVS1—35G〉T和c．88A〉G）属首次报道。酶切发现1例患者携带mt．1555纯合突变,后经测序发现还携带有mt．1438A〉G突变位点。结论吕梁地区耳聋患者以GJB2C．235delC为主要致病位点,本次研究结果为吕梁地区的耳聋预防奠定了基础,同时为今后临床医师诊断、治疗及遗传咨询提供了参考。     

一个先天性肌营养不良症家系的POMT1基因突变鉴定与产前诊断CSCD

目的确定1个先天性肌营养不良症（congenital muscular dystrophy, CMD）家系的POMT1致病基因突变,并对该家系中孕11周的胎儿进行产前诊断。方法收集1例CMD患者及其表型正常父母的外周血标本,抽取母亲孕11周胎儿的绒毛标本。采用PCR扩增POMT1基因的第19和第20外显子,对PCR产物进行双向测序检测基因突变,明确致病突变来源后,进一步对胎儿进行产前诊断。结果先证者POMT1基因第19外显子检测到C．1939G〉A（P．Ala647Thr）杂合错义突变,来自其母亲;第20外显子检测到C．2141delG（P．Trp714Ter）杂合框移突变,导致蛋白质翻译的提前终止,该突变来自其父亲。产前诊断结果显示胎儿携带POMT1基因第19外显子c．1939G〉A杂合错义突变,推测其为与母亲相同POMn基因致病突变携带者的可能性大。结论POMT1基因第19外显子C．1939G〉A错义突变和第20外显子C．2141delG移码突变的复合杂合突变可能是该CMD家系的致病原因,符合常染色体隐性遗传的规律,通过基因产前诊断可以有效阻止致病突变的传递。     

中国冠状动脉粥样硬化性心脏病患者MEF2A基因的新突变研究

目的研究冠状动脉粥样硬化性心脏病（简称冠心病）患者MEF2A基因在中国人群突变情况。方法应用聚合酶链反应．单链构象多态性（polymerase chain reaction-single strand conformation polymorphism，PCR-SSCP）和DNA测序技术检测156例散发性冠心病（coronary artery disease，CAD）患者及93名健康人MEF2A基因第11外显子。结果在SSCP泳动异常标本中进行DNA直接测序后发现1例患者MEF2A基因147130（C→A）错义突变（P431Q）、147191（G→T）同义变异以及147108-147128位点21个碱基缺失而导致了7个氨基酸（424QQQQQQQ430）丧失。另有两例患者仅在147108-147128位点发现上述同样的21个碱基缺失而无错义突变和同义变异的改变。健康对照组未发现此错义与缺失突变，却发现存在同样的同义变异。结论冠心病患者在MEF2A基因第11外显子存在新的突变，此突变可能为病理性突变。     

维吾尔族及汉族早发性乳腺癌 BRCA1基因突变分析

目的研究维吾尔族及汉族早发性乳腺癌患者BRCA1突变情况及突变位置。方法选取35例维吾尔族及汉族早发性乳腺癌根治标本（其中维吾尔族早发性乳腺癌22例,汉族乳腺癌13例）,对照组为32例维汉族乳腺良性病变（纤维腺病及纤维腺瘤）及乳腺癌旁非癌组织;运用PCR—SSCP和DNA序列测定的方法检测BRCA1基因突变。结果（1）35例新疆早发性乳腺癌（≤35岁）BRCA1突变率为22．86％（8／35）,22例维吾尔族早发性乳腺癌BRCA1突变率为31．82％（7／22）。（2）35例新疆早发性乳腺癌中发现8例BRCA1突变的12个新位点,其中2例突变位点IVS20-68insA均为维吾尔族早发性乳腺癌患者。（3）35例新疆早发性乳腺癌中发现7例BRCA1基因核苷酸多态性,对照组32例维吾尔族及汉族乳腺癌旁非癌组织及乳腺良性病变中仅发现1例BRCA1基因核苷酸的多态性。结论BRCA1突变可能与新疆早发性乳腺癌尤其是维吾尔族早发性乳腺癌密切相关,其突变位点IVS20—68insA可能是新疆维吾尔族早发性乳腺癌的遗传易感性位点,尚需扩大样本进一步研究证实。     

榆次地区非综合征性耳聋患者GJB2基因的检测分析

目的通过对榆次地区100q,J非综合征性耳聋患者GJB2基因突变位点的筛查,了解该地区耳聋基因的突变特点,为耳聋的早期诊断提供依据。方法收集榆次地区100例非综合征性耳聋患者的外周血标本,提取全血基因组DNA后,用聚合酶链反应（PCR）对目的片段进行扩增并测序,结果在GenBank上比对分析。结果100例耳聋患者中,检测到90例患者发生基因突变,其中有3,k位点未见报道：c．54C〉A（2．5％）、c．319h〉G（0．5＊／0）、c．512-5l3insAhCG（O．5％）;4个位点突变发生率较高：C．79G〉A（26．50％）、c．235delC（12．00％）、c．341A〉G（20．50％）、c．765T〉C（13．50％）;另外还检测出8个突变发生率较低的位点：c．109G〉A（1．5％）、C．176-19ldell6（1．00％）、C．223C〉T（1．00％）、c．253T〉C（0．50％）、c．299-300delAT（3．50％）、C．328delG（0．50％）、c．368C〉h（0．50％）、C．608T〉C（2．00％）。结论通过对榆次地区耳聋患者GJB2基因的检测分析,可以明确耳聋患者的病因,了解该地区的耳聋基因突变情况,为今后的耳聋患者的病因学诊断提供参考。     

大同地区耳聋基因GJB2和mtDNA1555突变分析

目的通过筛查大同地区87例耳聋患者常见基因GJB2和mtDNA1555的突变频率,研究该地区CJB2和mtD-NA1555基因突变情况及热点突变位点。方法采集大同地区87例耳聋患者外周血,对目的基因扩增并进行测序分析。结果所有患者中有58例GJB2基因检测到11个突变位点,与编码连接蛋白的非综合征耳聋突变数据库（http：／／davinci．crg．es／deafness／index．php？section=mut_db＆db=nonsynd）比对,9个位点已见报道,其中包括5个多肽位点c．79G〉A、c．341A〉G、c．608T〉C、c．368C〉A、c．765T〉C和4个致病住点c．235delc、c．109G〉A、c．176-c．191del16和c．299-c．300delAT,其中,c．79G〉A是主要突变方式,携带率为24．14％（42／174）。新发现两例未见报道的突变位点c．277A〉G和c．558G〉A;患者中只有1例检测到mtDNA1555A〉G位点突变。结论通过对大同地区GJB2基因和mtD-NA1555突变位点的研究,了解大同地区该基因突变谱,为后续国内耳聋基因型分布提供数据支持,同时也为耳聋的早期诊断,治疗提供理论依据。     

Mutation analysis of BRCA1 gene in African-American patients with breast cancer

An estimated 7% of all breast cancers and 10% of all ovarian cancers are associated with inherited mutations in BRCA1 and BRCA2 genes. The mutations of a breast cancer-susceptible gene, BRCA1, confers increased risk of breast cancer in young women. Numerous studies have reported specific mutations in the BRCA1 and BRCA2 genes in the white population. However, there are very few studies on African-American and other ethnic minority groups. The goal of this study is to identify whether African-American patients with breast cancer carry some common mutations reported in other ethnic groups and whether they carry some novel mutations. We screened hot-region mutations on exons 2, 5, 11, 16, and 20 of BRCA1 gene in 54 African-American patients with breast cancer by NIRCA and SSCP methods. Our data revealed one novel frameshift mutation (3331 insG) and three missense sequence variants (A3537G, A3667G, and C4009T) on exon 11. Each sequence change was confirmed by automatic DNA sequencing. One rare sequence variant, A3537G, has been revealed in high frequency (3/54). Our data suggested that African-American patients with breast cancer carry some unique BRCA1 gene mutations.     

Germline mutations in the PTEN gene in Israeli patients with Bannayan-Riley-Ruvalcaba syndrome and women with familial breast cancer

Germline mutations in BRCA1 or BRCA2 account for the majority of inherited breast cancer cases. Yet, in up to 40% of familial breast cancer cases, no mutations can be detected in either gene. Germline mutations in PTEN underlie two inherited syndromes: Cowden disease (CD) and Bannayan-Riley-Ruvalcaba syndrome (BRRS). The known association of CD with breast cancer risk made it plausible that germline mutations within PTEN may play a role in inherited predisposition to breast cancer. The nine coding exons of the PTEN gene were screened for harboring germline mutations using denaturing gradient gel electrophoresis (DGGE) complemented by sequencing, in two subsets of Israeli patients: 12 patients clinically diagnosed with BRRS, and 89 women with an apparent inherited predisposition to breast cancer, some with salient features of CD. Two of three familial BRRS patients exhibited novel germline mutations in PTEN: a missense mutation changing methionine to arginine at codon 134, and insertion of two nucleotides (CA) at cDNA position 1215 resulting in a frameshift at codon 61 and a premature stop at codon 99. Among 89 high-risk women, two missense mutations were detected in exon 4: A to C change at cDNA position 1279 resulting in a change of aspargine to threonine at codon 82 (N82T), and a G to an A alteration in 1269 which alters threonine to alanine at codon 78 (T78A), a non-conservative missense mutation. This study suggests that PTEN does not play a major role in predisposing to hereditary breast cancer in Israeli women, and that detection of PTEN mutations in BRRS patients is more likely in familial cases.     

Founder mutation in the BRCA1 gene in Malay breast cancer patients from Singapore

The mutation spectrum of the BRCA1 gene among ethnic groups from Asia has not been well studied. We investigated the frequency of mutations in the BRCA1 gene among Malay breast cancer patients from Singapore, independent of family history. By using the protein truncation test (PTT) and direct sequencing, BRCA1 mutations were detected in 6 of 49 (12.2%) unrelated patients. Four novel missense mutations in exon 11, T557A (1788A>G), T582A (1863A>G), N656S (2086A>G) and P684S (2169C>T) were identified in one patient. Two patients had missense mutations in exon 23, V1809A (5545T>C), which has been previously detected in individuals from Central and Eastern Europe. Three unrelated patients had the deleterious 2846insA frameshift mutation in exon 11. Methylation specific PCR (MSP) of the promoter region of the BRCA1 gene detected hypermethylation of tumor DNA in an additional 2 patients. Haplotype analysis using the microsatellite markers D17S855, D17S1323 and D17S1325 revealed a common haplotype for the three unrelated patients and their three relatives with the 2846insA mutation. These findings strongly suggest that the 2846insA mutation, the most common deleterious mutation in this study, may possibly be a founder mutation in breast cancer patients of Malay ethnic background.     

忻州地区耳聋患者常见耳聋基因GJB2、GJB3和线粒体DNA 12S rRNA 1555A〉G相关性分析

目的通过对忻州地区83例耳聋患者常见基因GJB2、GJB3和线粒体DNA 12S rRNA 1555A〉G测序分析,从分子水平研究该地区人群聋病的遗传病因和特点,为临床防聋治聋提供策略、依据。方法收集忻州地区83例耳聋患者外周血样本,提取DNA后对目的基因扩增并进行测序分析。结果83例耳聋患者中GJB2基因检测到57例发生突变,9个突变位点,与编码连接蛋白的非综合症耳聋突变数据库（http：／／davinci．crg．OS／deafneSS／index．php？Seccion=mut_db＆db=nonsynd）比对,8个位点已见报道,其中包括3个多态位点c．79G〉A、c．341A〉G、c．368C〉A和5个致病位点c．235delC、c．30-35delC、c．109G〉A、c．176-c．191dell6和c．299-c．300delAT,其中,c．79G〉A和c．341A〉G是主要突变方式,携带率为30．12％（42／174）和23．49％（39／166）。新发现1例未见报道的突变位点c．186C〉T;患者均未检测出GJB3和线粒体DNA12SrRNA1555A〉G基因突变位点。结论通过对忻州地区常见耳聋基因突变位点的研究,了解忻州地区该基因突变谱,为后续国内耳聋基因型分布提供数据支持,同时也为耳聋的早期诊断、治疗提供理论依据。     

山西省部分地区Leber遗传性视神经病变11778G〉A位点的检测分析

目的探讨山西省Leber遗传性视神经病变11778G〉A住点的突变携带情况及突变特点。方法针对91例疑似Leber遗传性视神经病变患者的11778G〉A原发性位点设计引物,进行PCR扩增并测序,测序结果在GenBank上比对分析。结果91例疑似Leber遗传性视神经病变患者中,确诊23例携带11778G〉A位点的突变,占25．3％,其中仅有1例单独携带11778G〉A,14例携带11778G〉A＋11719 G〉A,其余均携带除11778G〉A以外的突变。结论山西省Leber遗传性视肿经病变患者中,11778G〉A突变位点较高,这一特点对于临床实践具有重要的提示作用,大大提高了基因诊断的效率。     

BRCA1 germline mutations in Indian familial breast cancer

Germline mutation analysis of BRCA1 gene has demonstrated significant allelic heterogeneity. These differences represent historical influences of migration, population structure and geographic or cultural isolation. To date, there have been no reports of Indian families with mutations in BRCA1. We have screened for mutations in selected coding exons of BRCA1 and their flanking intron regions in three breast or breast and ovarian cancer families with family history of three or more cases of breast cancer under age 45 and/or ovarian cancer at any age. We have also analyzed 10 female patients with sporadic breast cancer regardless of age and family history, as well as 50 unrelated normal individuals as controls. Thus a total of 90 samples were analyzed for BRCA1 mutations using polymerase chain reaction-mediated site directed mutagenesis (PSM) and single stranded conformation polymorphism (SSCP) analysis for various selected exons followed by sequencing of variant bands. Eight point mutations were identified. Two deleterious pathogenic, protein truncating non-sense mutations were detected in exon 11 (E1250X) and exon 20 (E1754X) and six novel and unique amino acid substitutions (F1734S, D1739Y, V1741G, Q1747H, P1749A, R1753K). One complex missense mutation of exon 20 [V1741G; P1749A] was seen in two out of three families and another complex combination of missense and non-sense mutations of the same exon [V1741G; E1754X] was observed in only one family. These complex mutations exist only in breast cancer families but not in control populations of women. Three splice site variants (IVS20+3A>C, IVS20+4A>T, IVS20+5A>T) and two intronic variants (IVS20+21_22insG, IVS20+21T>G) were also detected. In the group of 10 sporadic female patients no mutations were found.     

阳泉地区非综合征性耳聋患者常见耳聋基因突变的分析

目的通过对阳泉市盲聋哑学校69例耳聋患者进行GJB2、PDS及线粒体DNA基因热点突变筛查,分析该地区耳聋的突变分布及分子病因。方法收集山西省阳泉市69例耳聋患者,对所有患者线粒体DNAA1555G／C1494T、GJB2基因、PDS基因第7、8和19外显子进行扩增及测序。结果69例非综合征性耳聋患者共有60例检测到基因突变,突变率为86．96％（60／69）。57例患者检出GJB2基因突变,检出率达82．61％（57／69）,其中C．235delC突变率为10．14％;3例患者有PDS基因突变,分别为c．2168A〉G l例,IVS7-2G〉A 2例;未检测到线粒体DNAA1555G／C1494T突变。结论山西省阳泉市常见耳聋基因突变以GJB2基因突变率较高,为耳聋的诊断与治疗提供依据。     

BRCA2 germline mutations in Cypriot patients with familial breast/ovarian cancer

Germline mutations in the BRCA2 gene have been shown to be associated with familial female and male breast cancer. Mutations occur throughout the entire coding region of the gene, and there is considerable ethnic and geographical diversity in the deleterious mutations detected in different populations. No data exist on the role of the BRCA2 gene in the Cypriot population. In this study we present the results of characterizing mutations in the BRCA2 gene, in 26 Cypriot families with multiple cases of breast/ovarian cancer. The entire coding region, including splice sites, of BRCA2 were sequenced using cycle sequencing. In total 29 BRCA2 variants were detected which include 3 truncating mutations, 8 missense mutations, 6 polymorphisms and 12 intronic variants. The 3 truncating mutations are frameshift mutation 8984delG (exon 22), and two nonsense mutations, namely C1913X (exon 11) which is a novel mutation, and K3326X (exon 27). It is of interest that frameshift mutation 8984delG was the most frequent, since it was detected in 5 patients from three different families. Among the 6 polymorphisms detected, polymorphism T77T is novel and similarly 4 of the 12 intronic variants were also novel, namely IVS1+8G>A, IVS1-96insA, IVS4+36A>G and IVS11-51G>T. These results show that deleterious BRCA2 mutations, occur at the same frequency, about 20%, in Cypriot families, as that recorded in other European populations. We conclude that the BRCA2 gene plays a significant role in the familial breast cancer phenotype in the Cypriot population.