氨基糖苷类抗生素致聋家系线粒体DNA 12S和16S rRNA基因突变分析

目的:研究线粒体rRNA基因突变与氨基糖苷类抗生素致聋遗传易感性的关系,为建立相应的基因诊断方法提供依据。方法:收集5个有明确氨基糖苷类抗生素应用史的耳聋家系27名成员的外周静脉血标本,从白细胞中提取DNA,PCR扩增线粒体DNA片段,Alw26I限制性内切酶分析和DNA序列分析检测A1555G点突变,并对其中一个家系进行了线粒体DNA12S和16S rRNA基因全序列分析。结果:家系A、C、D和E的21份样品均为A1555G点突变阳性,家系B的6份样品为A1555G点突变阴性。家系B线粒体DNA12S和16S rRNA基因全序列分析显示,该家系存在16S rRNA基因第2227位“AA”插入突变。结论:本研究发现了一个A1555G点突变阴性的氨基糖苷类抗生素致聋家系,说明线粒体DNA A1555G点突变不是氨基糖苷类抗生素遗传易感性惟一的分子基础,对氨基糖苷类抗生素致聋遗传易感性的预测仅检测A1555G点突变是不够的,应与mtDNA其他相关突变位点的检测结合起来。     

军事噪声性听力损失的线粒体基因变异分析

目的研究线粒体基因变异与军事噪声性听力损失遗传易感性的关系,为确定噪声易感个体的分子诊断方法提供依据。方法对云南某部接触军事噪声的406名坦克兵、626名炮兵共计1032例进行听力损失调查,收集军事噪声易感者(易感组)82例,耐受者(耐受组)40例,共计122例。分别采集外周静脉血标本,从白细胞中提取DNA,PCR扩增线粒体DNA及非综合征型耳聋相关的热点突变部分片段,进行基因测序比对分析,比较两组中存在碱基改变的位点分布例数。对测序结果中存在与耳聋相关的碱基改变的个体做进一步的听力学分析。结果军事噪声易感者和耐受者的线粒体基因存在一定差异,线粒体COII基因T7684C和G7853A两个位点的变化只存在于易感组,两组间有显著性差异(P<0.05)。A827G、T961insC(异质)、T1005C、T1095C、G7444A等可能与耳聋相关的线粒体基因改变多见于易感组,耐受组也有分布。结论携带线粒体COII基因T7684C和G7853A碱基变化的个体可能对军事噪声更加易感。     

DHPLC在X-连锁肾上腺脑白质营养不良分子诊断中的应用(附12例报告)

目的探讨DHPLC在X-连锁肾上腺脑白质营养不良(X-ALD)分子诊断中的应用。方法提取12个X-ALD家系及成员的外周血基因组DNA,分15个片段扩增ABCD1基因的10个外显子,应用DHPLC技术对其进行突变筛查,并对出现异常洗脱峰的PCR产物进行DNA序列测定,证实突变位点的存在。结果12个X-ALD家系存在12种不同的ABCD1基因突变,包括8个错义突变、2个移码突变和2个无义突变,即P534R、G343V、R259W、A141T、R401Q、K276E、Y174C、A314P、fs E471、fs A247、S108X和Q177X。结论DHPLC筛查结合DNA序列测定能快速有效检测出ABCD1基因突变。不同的X-ALD家系有不同的ABCD1基因突变位点,突变类型和表型之间无特殊相关关系。     

沈阳地区孕妇常见耳聋基因突变位点筛查及临床意义

目的对孕妇耳聋基因常见突变位点筛查,探讨在表型正常的孕妇中开展耳聋一级预防的意义。方法选取自2015年4月至2017年4月在沈阳市妇幼保健院遗传检验科行耳聋基因突变位点筛查且听力正常的1 133例孕妇为研究对象。首先,应用北京博奥生物有限公司遗传性耳聋基因芯片对孕妇进行常见耳聋基因突变位点筛查;其次,当孕妇筛查结果为耳聋基因突变携带者,其配偶进行耳聋基因常见突变位点筛查,同时进行常见耳聋基因测序分析;最后结合筛查结果对耳聋基因携带者进行遗传咨询,对同一基因上均有耳聋基因突变位点的夫妻双方建议进行产前诊断。结果 1 133例受检孕妇中,筛查出耳聋基因突变携带者64例,占检测人群(携带率)的5.65%(64/1 133);GJB2、SLC26A4、GJB3、mtDNA12S rRNA基因突变携带率分别为2.56%(29/1 133)、1.50%(17/1 133)、0.35%(4/1 133)、1.24%(14/1 133)。其中,有4对夫妻双方均为耳聋致病基因携带者,两对夫妻二人为不同基因上耳聋致病基因携带者;另有两对夫妻为同一基因携带者。结论常见耳聋基因突变在正常人群中有较高的携带率,听力正常的夫妻在孕期、产前行耳聋基因芯片筛查可极大预防和减少遗传性聋儿的出生。     

应用基因芯片技术检测乙型肝炎病毒前-C区/BCP区基因突变的研究

目的　探讨利用基因芯片技术检测乙型肝炎病毒 (HBV)前 C区 /BCP区基因突变方法的临床价值及前 C区 /BCP区基因突变的临床意义。方法　应用基因芯片技术检测 4 6例急慢性肝病的HBV前 C区A1896 (nt1896G→A)、A1899(nt1899G→A)及HBVC基因启动子 (BCP)T176 2A176 4 (nt176 2A→T、nt176 4G→A)四位点突变 ,并探讨该技术的临床应用价值。结果　用基因芯片法测定HBV基因特定变异位点特异性强 ,阳性率为 87 0 %。A1896突变 18例 (4 5 0 % ) ,A1899突变 10例 (2 5 0 % ) ,T176 2A176 4联合突变 30例(75 0 % ) ,多位点突变 14例(35 0 % )。各变异组与未变异组比较 ,肝功损害均有显著性差异 (P <0 0 5～ 0 0 1)。前 C区 /BCP区基因突变在乙型肝炎肝硬化及慢性乙型肝炎中较为常见 ,在急性乙型肝炎中未检出。结论　应用基因芯片法测定HBV特定变异位点特异性强 ,可一次同时检测多个突变位点 ,具有一定的临床应用价值。     

GJB2基因突变始祖效应对中国耳聋人群的影响

目的 对中国耳聋患者中缝隙连接蛋白beta2(gap junction protein beta 2,GJB2)基因突变情况进行筛查,探寻该基因各种突变的分布情况。方法 在聋病门诊收集各种感音神经性聋患者141例,其中非综合征型耳聋135例(有家族史者17例),综合征型耳聋6例。另外收集听力正常者150例作为对照。采取PCR扩增、直接测序的方法检测GJB2基因突变。结果 在耳聋患者中发现7种GJB2基因碱基改变：79G→A,A,109G→A,341A→G,235deC,455A→G,176→191del16和504insGCAA。79G→A纯合15例,杂合5例;341A→G纯合4例,杂合8例;109G→A纯合1例,杂合4例;235deC纯合5例,杂合6例;176-191del16杂合3例;504insGCAA杂合2例;455A→G杂合1例。结论 在耳聋患者中开展GJB2基因的筛查工作可以将235delC作为一个候选突变筛查位点。     

GJB3基因在新疆维汉两民族遗传性非综合征耳聋患者的突变分析

目的耳聋具有高度的遗传异质性,分析GJB3基因在新疆地区维汉两族中的突变,了解其分子病因学机制。方法调查对象来自新疆地区非综合征耳聋患者（耳聋组）93例,其中维吾尔族43例。对照组为听力正常者110例．其中维吾尔族56例。所有受检者均采集外周血并提取DNA,应用聚合酶链反应（PCR）产物直接测序方法对各种感音神经性耳聋患者93名、对照组110名进行GJB3基因编码区突变检测及鉴定。结果在93名患者中发现GJB3基因的3种单核苷酸改变,其中有两种碱基变化导致了氨基酸的改变,为错义突变方式。其中1个突变（256G→A）,另1个突变形式（33C→T）为本研究首次发现。110名正常对照组中未发现同样突变。结论国人非综合征型遗传性聋者GJB3基因突变筛查研究发现了一个GJB3基因新的突变形式（256G→A）,为进一步开展耳聋相关基因的筛查研究打下了基础。     

山羊线粒体DNA细胞色素b基因序列分析

采用PCR直接测序法,对一个山羊群体线粒体DNA细胞色素b基因全序列进行测定。结果表明,山羊线粒体细胞色素b基因全长为1140bp,A、G、T和C碱基的平均含量分别为31.9%、13.1%、26.8%和28.2%,其中A T含量为58.7%,G C含量为41.3%,A T含量明显高于G C含量;密码子碱基的使用也存在一定差异。该研究为解决我国地方山羊品种起源系统中存在的分歧提供有益的探索。     

苯丙酮尿症患者苯丙氨酸羟化酶基因外显子5突变鉴定

目的 研究新疆地区苯丙酮尿症(PKU)患者中苯丙氨酸羟化酶基因第5外显子的突变特点.方法 应用PCR-SSCP分析技术结合基因序列测定方法进行筛查和鉴定.结果 在37例PKU患者共74条染色体中,检出基因突变4种,即错义突变F161S、剪接位点突变IVS 4-1G→A、错义突变R158Q及无义突变Y166X,其突变发生率分别为4.1%、1.4%、1.4%和1.4%,外显子5的等位基因突变频率是8.1%.对国内外研究资料和本文外显子5突变类型频率的比较分析显示,R158Q是欧洲及拉美等国普遍存在的突变型,IVS4-1G→A是亚洲黄种人常见的突变体,而F161S和Y166X则是新疆地区PKU患者特有的基因突变类型.结论 新疆地区是我国与亚欧地区之间一个较为特殊的PAH突变基因分布带,是研究突变基因多样性、PAH基因异质性特点以及人类起源、迁徙等的理想资源库.     

过氧化氢导致肠上皮细胞线粒体DNA编码基因损伤的研究

目的 :探讨过氧化氢 (H2 O2 )对肠上皮细胞线粒体DNA编码细胞色素C氧化酶、ATP合成酶基因的损伤作用。方法 :肠上皮细胞株 (SW - 4 80 ) ,采用 4mmol·L-1H2 O2 处理细胞后进行线粒体DNA的提取 ,对细胞色素C氧化酶 (COXⅠ、COXⅡ、COXⅢ )基因、ATP合成酶 (ATPase 6亚基、ATPase8亚基 )基因进行PCR扩增 ,并将PCR产物进行直接测序。结果 :细胞色素C氧化酶COXⅠ从 6 80 3～ 6 84 8出现大范围的点突变及 70 2 7出现点突变 (TC) ,在 732 9(CG)、7341(TG)、735 2 (GA)出现点突变 ,在 7337出现缺失突变 (缺T) ;COXⅡ序列在 82 19～ 82 6 0段出现大范围的点突变 ;Atpase 8亚基基因在 8385～ 85 4 3段出现大范围的点突变。结论 :H2 O2 可明显损伤mtDNA编码的细胞色素C氧化酶及ATP合成酶基因。     

Species identification by means of pyrosequencing the mitochondrial 12S rRNA gene

The aim of this study was to develop a new method for species identification based on the analysis of a very short nucleotide sequence. For this reason, the mitochondrial 12S rRNA gene, together with the new method of pyrosequencing, was used. The detection of only 20 nucleotides, following the sequencing primer within a 149-bp fragment by pyrosequencing, was sufficient to identify the biological origin of the samples by alignment with a reference sequence database. A case example with a piece of skin is presented, and the question whether this piece of skin came from a missing wife or from an animal could be answered.     

肾上腺肿瘤的CT诊断(附46例分析)

目的:探讨肾上腺肿瘤在CT上的表现特点,以提高对该部位肿瘤的认识。方法:收集46例肾上腺肿瘤,回顾分析CT特征,对照病理结果进行讨论。结果:46例中,皮质腺瘤21例,多数较小,边缘光滑,轻度强化;转移瘤7例,单侧或双侧,密度均匀或不均匀;嗜铬细胞瘤6例,肿块一般较大,密度不均,增强后实质部分强化明显;髓性脂肪瘤6例,瘤内脂肪组织为其特征;皮质腺癌3例,较大肿块,直径一般大于7 cm,密度不均;肾上腺囊肿2例,边缘光滑,均匀水样密度的囊性占位,增强扫描无强化;非何杰金淋巴瘤1例,双侧发生,软组织密度肿块,强化较均匀。结论:肾上腺肿瘤CT表现各有特征,结合临床表现和生化检查可作出较为正确的诊断。     

4例与GJB2基因相关的遗传性耳聋家系的鉴别诊断

 目的 通过遗传学检测明确4例先天性耳聋家系的致病突变,并加以鉴别,针对性地给出诊疗意见。方法 选取2020-05至2022-01于北京妇产医院产前诊断中心遗传咨询门诊就诊的4例先天性耳聋家系。利用耳聋基因芯片、全外显子组测序的实验方法,明确其遗传学致病突变,并提供针对性的咨询意见。结果 4例遗传性耳聋均与GJB2基因相关,但存在不同情况。例1为常染色体显性掌跖角化病伴耳聋,其致病变异c.167T>C属新报道;例2中,夫妻双方分别为MYO7A与GJB2复合杂合突变导致的先天性耳聋,其中妻子携带2个新报道致病变异,即MYO7A: c.1214G>A和MYO7A: c.3545A>G;例3为GJB2复合杂合突变引起的常染色体隐性耳聋;例4为GJB2复合杂合突变导致的迟发性耳聋。结论 与GJB2基因相关的先天性耳聋具有较强的临床异质性,遗传检测是对其鉴别诊断的必要手段。     

Congenital brain tumors: a review of 45 cases

Forty-five pathologically proved cases of neonatal brain tumors (diagnosed in neonates within 60 days after birth) were reviewed from the neuroradiology archives dating back to 1964. CT was performed in 24 cases, MR in five, sonography in six, and angiography in seven. Two-thirds of the lesions were supratentorial. The most common histology was a tumor composed of primitive or poorly differentiated tissues: 12 teratomas and 12 primitive neuroectodermal tumors, four of which were typical medulloblastomas. In addition, there were nine astrocytomas (grades I-III); four cases of glioblastoma multiforme (astrocytoma grade IV); three choroid plexus papillomas; and single cases each of ependymoma, medulloepithelioma, germinoma, angioblastic meningioma, and ganglioglioma. The dominant CT appearance, regardless of histology, was a large heterogeneous lesion with associated hydrocephalus. Coarse calcification was a constant feature in the teratomas. Prognosis was poor overall, with the longest survival seen in choroid plexus papilloma and astrocytoma. Imaging studies are most valuable in identifying and distinguishing potentially curable lesions such as choroid plexus papillomas (variably sized intraventricular lesions with homogeneous enhancement) from rapidly fatal tumors such as teratomas (large heterogeneous lesions with coarse calcifications and associated hydrocephalus).     

Congenital brain tumors: a review of 45 cases

Forty-five pathologically proved cases of neonatal brain tumors (diagnosed in neonates within 60 days after birth) were reviewed from the neuroradiology archives dating back to 1964. CT was performed in 24 cases, MR in five, sonography in six, and angiography in seven. Two-thirds of the lesions were supratentorial. The most common histology was a tumor composed of primitive or poorly differentiated tissues: 12 teratomas and 12 primitive neuroectodermal tumors, four of which were typical medulloblastomas. In addition, there were nine astrocytomas (grades I-III); four cases of glioblastoma multiforme (astrocytoma grade IV); three choroid plexus papillomas; and single cases each of ependymoma, medulloepithelioma, germinoma, angioblastic meningioma, and ganglioglioma. The dominant CT appearance, regardless of histology, was a large heterogeneous lesion with associated hydrocephalus. Coarse calcification was a constant feature in the teratomas. Prognosis was poor overall, with the longest survival seen in choroid plexus papilloma and astrocytoma. Imaging studies are most valuable in identifying and distinguishing potentially curable lesions such as choroid plexus papillomas (variably sized intraventricular lesions with homogeneous enhancement) from rapidly fatal tumors such as teratomas (large heterogeneous lesions with coarse calcifications and associated hydrocephalus).     

16S rRNA全基因序列分析鉴定我国南方蜱中单核细胞埃立克体

目的 :测定蜱中单核细胞埃立克体的 16SrRNA全基因序列 ,鉴定病原菌。方法 :应用从16SrRNA基因构建的特异和通用引物进行PCR ,从越原蜱标本中分段扩增查菲埃立克体DNA ,进行克隆和序列测定 ;将其连成完整序列与埃立克体族中其他微生物进行同源性比较 ,并以相等数量定位碱基的核苷酸序列进行遗传发育分析。结果 :测定序列全长 146 3bp ,与美国查菲埃立克体分离株的 16SrRNA基因序列相差 6个核苷酸 ,同源性为 99.6 % ,遗传发育分析两者无明显差异 ;与犬埃立克体、尤氏埃立克体、小鼠埃立克体的同源性为 97.5%～ 98.0 % ,属于同一个基因群 ;与其他埃立克体种的同源性为 83.0 %～ 92 .9%。结论 :首次报道了我国南方蜱中埃立克体的 16SrRNA全序列 ,确定了其分类位置 ,为进一步开展疫源地调查奠定了基础     

Mitochondrial 16S ribosomal RNA gene for forensic identification of crocodile species

All crocodilians are under various threats due to over exploitation and these species have been listed in Appendix I or II of CITES. Lack of molecular techniques for the forensic identification of confiscated samples makes it difficult to enforce the law. Therefore, we herein present a molecular method developed on the basis on 16S rRNA gene of mitochondrial DNA for identification of crocodile species. We have developed a set of 16S rRNA primers for PCR based identification of crocodilian species. These novel primers amplify partial 16S rRNA sequences of six crocodile species which can be later combined to obtain a larger region (1290 bp) of 16S rRNA gene. This 16S rRNA gene could be used as an effective tool for forensic authentication of crocodiles. The described primers hold great promise in forensic identification of crocodile species, which can aid in the effective enforcement of law and conservation of these species.     

The utility of prescreening for hepatitis A in military recruits prior to vaccination

The U.S. Army administers the hepatitis A virus (HAV) vaccination for prophylaxis against HAV infection. There is little comparative data as to whether prescreening for previous HAV infection before immunization is less costly than universal vaccination. We designed a study to determine the prevalence of previous HAV infection in U.S. Army recruits and then perform a cost analysis. The cost analysis compared selective vaccination versus universal vaccination. Basic demographic information, including age, gender, geographic origin, and ethnicity, were collected after which patients were tested for HAV antibodies. A total of 1,332 individuals was prospectively enrolled with 183 individuals (13.74%) having evidence of previous HAV infection. Minority recruits were found to have a higher prevalence than Caucasian recruits (p = 0.0451. The cost analysis demonstrates that vaccination without prescreening was the least costly of two vaccination strategies for this cohort. To achieve current vaccination goals, all U.S. military recruits should be vaccinated without evaluation for previous HAV immunity.