非综合征型遗传性聋家系系谱分析及mtDNA 12SrRNA tRNA^Leu（UUR） tRNA^Ser（UCN）基因突变分析

目的：探讨非综合征型遗传性聋(NSHL)家系中线粒体基因(mtDNA)突变所占比重以及母系遗传的统计学规律。探讨mtDNA突变与遗传性聋的关系及突变在这类家系及散发感音神经性聋(SNHL)中的发生率。方法：收集遗传性NSHL家系29个，行家系调查；对家系进行形式遗传学分析、分离分析；采取外周血，从白细胞中抽取DNA；以多重聚合酶链反应(PCR)法检测mtDNA(nt)1555^G、7445^G、3243^G点突变；行mtDNA 12SrRNA，tRNA^Leu(UUR)及tRNA^Ser(UCN)基因序列测定。结果：多重PCR检测示mtDNA突变家系12个；形式遗传学分析确定为显性遗传不规则外显的家系，mtDNA突变率高；分离分析结合mtDNA突变检测示：母系遗传不具有常染色体遗传基因分离比。经测序证实，12个家系具有mtDNA突变；形式为：1555^G突变家系10个，7445^G突变家系2个，未发现3243^G突变家系。结论：母系遗传与常染色体显性及隐性遗传基因传递分离比有差异；mtDNA突变在NSHL中占较高比例，主要形式是1555^G及7445^G突变。在散发病例中发生率很低；7445^G结合1555^G点突变筛查对SNHL的诊断有重要意义。多重PCR法是mtDNA多基因突变位点简便的检测方法。     

无综合征耳聋与线粒体DNA1555^A→C突变

目的：分析４个无综合征耳聋家系是存在线粒体ＤＮＡ１５５５＾Ａ→Ｃ的突变。方法：以ＰＣＲ－ＲＦＬＰ方法进行线粒体ＤＮＡ１５５５＾Ａ→Ｃ突变筛查。结果 仅１个无综合征耳聋家系中的５个成员有４个存在该突变。结论：线粒体ＤＮＡ１５５５＾Ａ→Ｃ点突变与部分无综合征耳聋有一定关系。     

西北五省573例非综合征型耳聋患者线粒体 DNA A1555G突变分析

目的：分析西北地区非综合征性耳聋人群中线粒体DNA A1555G突变发生频率。方法：通过标准化的流行病学调查设计、行政组织、标本采取和线粒体DNA 12SrRNA A1555G筛查方法进行西北5个省市自治区的重度感音神经性耳聋患者的一般情况和分子病因学调查。结果：收集来自西北5个省市573例非综合征性重度至极重度感音神经性耳聋病例,筛查出线粒体DNA 12SrRNA A1555G突变病例31例。结论：在西北五省,线粒体DNA 12SrRNA A1555G突变检出率高于全国平均水平,通过干预可有效减少药物性耳聋的发生。     

无综合征耳聋与线粒体DNA1555A→G突变

目的 :分析 4个无综合征耳聋家系是否存在线粒体 DNA15 5 5 A→ G的突变。方法 :以 PCR- RFL P方法进行线粒体 DNA15 5 5 A→ G突变筛查。结果 :仅 1个无综合征耳聋家系中的 5个成员有 4个存在该突变。结论 :线粒体DNA15 5 5 A→ G点突变与部分无综合征耳聋有一定关系。     

碱基淬灭探针技术单管检测线粒体DNA 12S rRNA A1555G及C1494T突变

目的 应用碱基淬灭探针技术建立单管同时检测线粒体DNA 12S rRNA A1555G和C1494T突变的方法.方法 探针的一端标记6-羧基荧光素,同时构建4个载体做为扩增模板,分别代表可能的4种基因型组合.对117例耳聋患者外周血标本进行线粒体DNA 12S rRNA A1555G和C1494T突变的检测,同时选取15例样本进行DNA测序,验证所建立方法的可靠性和准确性.结果 根据熔解曲线可以清晰地对线粒体DNA 12S rRNA 1555位点和1494位点的基因型做出判断.117例耳聋患者中3例携带A1555G突变(2.56％),1494位点未检出突变;基于碱基淬灭探针技术的单管检测方法与DNA测序的结果一致.结论 碱基淬灭探针单管检测技术可用于临床线粒体DNA突变耳聋基因检测.     

国人无综合征性耳聋患者的线粒体基因组7445A→G突变263例调查

目的 :探讨国人无综合征性耳聋 ( NSD)患者的线粒体 DNA 744 5 A→ G( m t DNA744 5 A→ G)突变的发生情况。方法 :对 32个 NSD家系 12 8例和 135例散发的 NSD患者 ,10 0例正常人 ,以 PCR法检测 mt DNA 744 5 A→ G突变情况。结果 :全部受检者无 mt DNA744 5 A→ G突变发生。结论 :国人 NSD患者的 m t DNA744 5 A→ G突变的发生率较低 ,且明显低于 mt DNA15 5 5 A→ G的突变发生率     

非综合征型遗传性聋家系系谱分析及mtDNA 12SrRNA tRNALeu(UUR)tRNASer(UCN) 基因突变分析

目的探讨非综合征型遗传性聋(NSHL)家系中线粒体基因(mtDNA)突变所占比重以及母系遗传的统计学规律.探讨mtDNA突变与遗传性聋的关系及突变在这类家系及散发感音神经性聋(SNHL)中的发生率.方法收集遗传性NSHL家系29个,行家系调查;对家系进行形式遗传学分析、分离分析;采取外周血,从白细胞中抽取DNA;以多重聚合酶链反应(PCR)法检测mtDNA(nt)1 555G、7 445G、3 243G点突变;行mtDNA12SrRNA,tRNALeu(UUR)及tRNASer(UCN)基因序列测定.结果多重PCR检测示mtDNA突变家系12个;形式遗传学分析确定为显性遗传不规则外显的家系,mtDNA突变率高;分离分析结合mtDNA突变检测示母系遗传不具有常染色体遗传基因分离比.经测序证实,12个家系具有mtDNA突变;形式为1 555G突变家系10个,7 445G突变家系2个,未发现3 243G突变家系.结论母系遗传与常染色体显性及隐性遗传基因传递分离比有差异;mtDNA突变在NSHL中占较高比例,主要形式是1 555G及7 445G突变.在散发病例中发生率很低;7 445G结合1 555G点突变筛查对SNHL的诊断有重要意义.多重PCR法是mtDNA多基因突变位点简便的检测方法.     

DNA双链断裂修复能力与分化型甲状腺癌发生风险的病例对照研究

目的:研究DNA双链断裂（DNA double-strand breaks,DSB）修复能力的影响因素及其与分化型甲状腺癌（DTC）发生风险的关系。方法:回顾性分析河南省肿瘤医院2020年1月至3月收治的140例甲状腺疾病患者,其中男性26例,女性114例,年龄18~78岁。依据病理结果将患者分为DTC组（90例）与对...     

人类颞骨火棉胶切片中线粒体DNA的扩增及重组测序

目的应用分子生物学技术建立人类颞骨火棉胶切片中的ＤＮＡ分析方法。方法采用多聚酶链反应（ｐｏｌｙｍｅｒａｓｅｃｈａｉｎｒｅａｃｔｉｏｎ，ＰＣＲ）配合不同的引物、扩增方式及酶切技术检测长期保存的７例（９侧）颞骨火棉胶切片中微量线粒体ＤＮＡ的片段缺失及点突变，ｐＧＥＭＴ载体进行扩增片段的重组与克隆。结果９侧颞骨ＤＮＡ提取液中均可见正常的１３５ｂｐ扩增片段，巢式ＰＣＲ检出其中２例生前患老年聋者（各查１侧）有线粒体ＤＮＡ大片段缺失，测序结果证实扩增的准确性。结论分子生物学技术在颞骨切片研究中的应用对于提高其回顾性研究水平有重要意义，目前可在耳科疾病的研究中发现相关的基因突变或病原体。     

DNA含量及形态参数对喉部恶性肿瘤前期病变的诊断价值

ＤＮＡ含量及形态参数对喉部恶性肿瘤前期病变的诊断价值董学武，王强，李潮，洪书丽，李辉，汪翠华，孙连玉细胞化学、ＤＮＡ定量化学和体视学的研究发展，为了解癌细胞的生长特性提供了客观手段。本文对喉正常粘膜上皮（Ｎｏｒｍｏｅｐｉｔｈｅｌｔｉｕｍ，ＮＥ）、喉乳...     

Mitochondrial mutation associated with nonsyndromic deafness

Purpose: The first mutation associated with nonsyndromic deafness has recently been identified in pedigrees with susceptibility to aminoglycoside ototoxicity and in a large Arab-Israeli pedigree. The mutation is maternally transmitted, and is a nucleotide substitution in the mitochondrial 12S ribosomal RNA gene. A different sequence change, in the mitochondrial tRNA^Ser(UCN)/COI gene, has been proposed as a candidate mutation in a Scottish nonsyndromic deafness pedigree. We have now identified a family in New Zealand with maternally inherited nonsyndromic sensorineural deafness, and the purpose of the current study is to identify the molecular basis of deafness in this family.Materials and Methods: A family tree was established by history and chart review, and audiological and clinical data were obtained. Blood was sampled from 10 family members, and lymphoblastoid cell lines were established for 4 of them. The DNA of these individuals was extracted, and the mitochondrial genome was analyzed by Southern blot analysis for gross rearrangements. Subsequently, the entire coding sequence of the mitochondrial genome was sequenced, compared to the normal sequence, and all sequence variations were analyzed by allele-specific oligonucleotide hybridization or restriction enzyme analysis.Results: Several candidate mutations were identified, one of them being the nucleotide 7445 A → G mutation in the mitochondrial tRNAse^Ser(UCN)/COI gene. This mutation was heteroplasmic and identical to the one previously identified in the Scottish pedigree.Conclusions: The finding of the same heteroplasmic mutation in two independent pedigrees with the same phenotype and transmission pattern, establishes this sequence change as the most likely determinant of the deafness phenotype in these families. This implies that nonsyndromic deafness can be caused by mutations in generalized cell processes, such as oxidative phosphorylation, rather than in hearing specific molecules.     

Coenzyme Q-10 treatment of patients with a 7445A--->G mitochondrial DNA mutation stops the progression of hearing loss

CONCLUSION: CoQ 10 may be helpful in delaying the progression of hearing loss in patients with the 7445A-->G mitochondrial mutation. Objective. To assess the effect of an antioxidant drug (Coenzyme Q-10) on the hearing level of patients with the mitochondrial DNA 7445A-->G mutation and associated sensorineural hearing loss (SNHL). Material and methods. We identified three patients with bilateral non-syndromic SNHL harboring the mitochondrial 7445A-->G mutation. Two patients had a family history of hearing loss with a strong matrilineal inheritance. The other patient did not have a family history of hearing loss. Two patients (1 with familial and 1 with sporadic SNHL) received treatment with 75 mg of Coenzyme Q-10 (CoQ10) twice a day for 1 year. The remaining patient with a familial form of hearing loss did not agree to take the treatment. Average bone conduction pure-tone thresholds for 0.5, 1, 2 and 4 kHz were obtained before and after diagnosis of mitochondrial hearing loss, and before and after treatment with CoQ10. Results. CoQ10-treated patients did not show any additional deterioration of their SNHL after 12 (familial case) and 13 months (sporadic case). The progression rate of SNHL was 6 dB/year in the 2 years prior to initiation of treatment in the familial case who received CoQ10 treatment. One year after being diagnosed with mitochondrial hearing loss, the patient who refused CoQ10 treatment exhibited an 11-dB deterioration of his hearing thresholds. There were no side-effects related to treatment with CoQ10.     

线粒体DNA突变与非综合征感音神经性聋

目的 分析非综合征感音神经性聋（non-syndromic sensorineural hearing loss,NSSNHL)患者及听力正常者中3种线粒体DNA（mitochondrial DNA,mtDNA)突变的发生频率，探寻mtDNA突变在NSSNHL发病中的可能作用。方法 收集年龄从3－84岁的61例散发的NSSNHL病例，6－68岁的19例听力正常人外周血，提取白细胞DNA，结合应用中断法聚合酶链反应（polymerase chain reaction,PCR)及引物交换PCR方法检测mtDNA^4977缺失，应用PCR方法及限制性片段长度多态性分析检测mtDNA^1555A→G和mtDNA3243A→G点突变，PCR产物以全自动激光荧光测序仪做序列分析。结果 （1）耳聋组及对照组的mtDNA^4977缺失检出率（缺失例数／总例数）分别为68．85％（42／61）及5．26％（1／19）；（2）所有样本均未检出mtDNA^1555A→G及mtDNA^3243A→G点突变。结论 NSSNHL组mtDNA^4977缺失发生频率明显高于听力正常组，提示mtDNA^4977缺失可能是NSSNHL患者发病的一个重要的作用因素；mtDNA^1555A→G点突变，mtDNA^3243A→G点突变在NSSNHL患者中不常见。     

线粒体DNA 12SrRNA A1555G突变在中国西北地区的流行病学研究

目的 调查中国西北地区非综合征感音神经性耳聋患者群体中线粒体DNA 12SrRNA A1555G突变的流行情况．评估开展这一突变检测的临床价值。方法 收集中国西北地区共612例感音神经性聋患者外周静脉血，从白细胞中提取DNA，多聚酶链反应（PCR）扩增线粒体DNA目的片断，Alw26I限制性内切酶检测A1555G点突变，而后对阳性病例的PCR产物进行DNA测序验证。结果 在612例感音神经性聋患者中，共发现56例A1555G突变患者：其中217例为药物性耳聋患者，有47例为A1555G点突变阳性；在其余395例非药物性耳聋患者中，检出9例A1555G突变。结论 中国西北地区的药物性耳聋较为常见，A1555G突变在本地区感音神经性耳聋人群中有较高的检出率（9．15％），在该地区开展线粒体DNA12SrRNAA1555G突变检测有重要意义。     

氨基糖甙类抗生素致聋家系线粒体DNA1555^G点突变分析

目的 考察１５５５＾Ｇ点在糖甙类抗生素致聋的对应关系，建立相应的基因诊断方法提供依据。方法 收集了３个有明确氨基糖甙类抗生素应用史的母系遗传耳聋家系１３人（包括聋人和听力正常者）的外周静脉血标本，聚合酶链反应扩增线粒体ＤＮＡ，Ａｌｗ２６Ｉ限制性内切酶分析、ＤＮＡ斑点杂交和ＤＮＡ序列分析检测１５５５＾Ｇ点突变。结果 家系１和３的７份样品均为１５５５＾Ｇ点突变阳性，家系２的６份样品为１５５５＾Ｇ点突变     

非综合征型聋患者线粒体DNA A1555G突变频率分析

目的分析甘肃地区非综合征型聋患者线粒体DNA 12SrRNA A1555G的突变频率。方法收集甘肃地区五所聋哑学校802例聋哑学生血样，经基因组DNA提取后进行聚合酶链反应（polymerase chain reaction，PCR）扩增线粒体DNA目的片段，用A1w26I限制性内切酶检测A1555G点突变，对酶切阳性病例的PCR产物纯化后进行直接测序验证酶切结果，分析线粒体DNA 12SrRNA A1555G在甘肃地区的突变频率。结果802例聋哑学生中有67例经酶切及直接测序证实为线粒体DNA A1555G突变，突变频率为8．4％（67／802）。其中有15例母系家庭成员中还有2例以上耳聋患者。结论线粒体DNA 12SrRNA A1555G点突变在甘肃地区非综合征型聋患者中占有很高的比例，高于国内外其他地区的相关报道。此研究结果不仅为绘制中国人群线粒体DNA A1555G突变频谱增添新的内容，也为因地制宜地开展耳聋基因诊断、实施遗传咨询及积极预防耳聋的发生有重要的指导意义。     

安阳市特教学校重度感音性聋分子病因学分析--GJB2 235delC突变和线粒体DNA 12SrRNA A1555G突变筛查报告

目的 调查河南省安阳地区重度感音神经性耳聋聋病分子病因学情况。方法对安阳市聋哑学校160名学生进行耳聋病因问卷调查、纯音听阈测试。对其中154名非综合征性感音神经性耳聋患者进行线粒体DNA 12SrDNA A1555G点突变检测和G朋12基因突变检测。结果 8例（5．19％）存在线粒体DNA 12SrDNA A1555G点突变；11例（7．14％）存在GJB2 235delC纯合突变；13例（8．44％）存在GJB2 235delC杂合突变。在分子水平能够明确诊断者占20．77％。结论 安阳地区耳聋患者存在较高的遗传性耳聋发生率。特别是线粒体DNA A1555G突变发生率高于全国平均水平，通过聋病分子诊断，可达到防聋、指导聋儿康复及评估耳聋预后等积极效果。     

Genetics of aminoglycocide-induced and prelingual non-syndromic mitochondrial hearing impairment: A review

Pathogenic mitochondrial DNA mutations are most often implicated in inherited and acquired hearing impairment. The current review mainly focuses on the 12S rRNA mitochondrial gene mutations associated with non-syndromic deafness without or after aminoglycosides exposure. Aminoglycoside-induced and nonsyndromic deafness has been shown to have a genetic susceptibility and the pathogenic mitochondrial 12S rRNA A1555G mutation was identified as the primary factor underlying the hearing loss in many familial as well as in genetically unrelated cases, particularly in Asian populations where aminoglycoside antibiotics are commonly used even for minor infections. Many families were shown to transmit the aminoglycoside ototoxicity through matrilineal inheritance and the A1555G mutation in the 12S rRNA gene was frequently identified. The aminoglycoside antibiotics are believed to target the mitochondrial ribosome in the cochlea resulting in abnormal RNA processing or decreased efficiency of translation thereby leading to irreversible auditory dysfunction. Such cases may have a genetic predisposition to aminoglycoside ototoxicity following autosomal dominant, autosomal recessive, X-linked, or mitochondrial pattern of inheritance.