【作者】 张哲文；

【导师】 郭玉芬；

【作者基本信息】 兰州大学 ， 遗传学， 2012， 博士

【摘要】 目的：本研究以新生儿为研究对象,探讨在新生儿听力筛查中进行聋病易感基因筛查的有效性和可行性,以弥补新生儿听力筛查中发现的不足和局限性,并且倡导在新生儿听力筛查中同步进行聋病易感基因筛查的理念。方法：以2009年11月-2011年4月期间出生于甘肃省14个地州市指定医疗卫生机构的10043名新生儿作为研究对象,进行新生儿听力和基因的同步筛查。新生儿听力初步筛查和复筛均采用筛查型耳声发射(otoacoustic emission,OAE),诊断性筛查采用自动判别听性脑干诱发电位(auto-auditory brainstem response, AABR)。初筛时间正常活产儿为出生后48h～72h内,高危儿在病情稳定后出院前进行检查。未通过筛查的新生儿42天后复查,阳性患儿的诊断性检查在出生后三个月进行。基因筛查采用北京解放军301医院王秋菊等设计的含有听力筛查信息和血样信息的新生儿遗传疾病筛查采样卡(ZL200720103139.4)采集新生儿脐带血。此采样卡可以直接用于线粒体12rRNA、GJB2基因以及SLC26A4基因的聚合酶连扩增反应(polymerase chain reaction, PCR)。对PCR结果的阳性产物测序验证。采用DNA Star软件对测序结果进行比对分析。结果：10043名新生儿中参加听力初筛9786例,初筛率97.4%,未参加初筛257例,其中,提前出院或转院221例,家长拒绝筛查29例,死亡7例。初筛通过8377(85.5%)；未通过1409例(14.4%,其中单耳732例,双耳677例。初筛未通过的1409例新生儿有1129例回院复筛,复筛率为80.1%。复筛通过767例(54.4%),单耳或双耳未通过362例(2.57%),280例未回院复筛,失访率为19.7%。基因筛查参加率为100%。聋病基因筛查结果显示：在10043名新生儿中,一共有2.29%(230/10043)新生儿携带一种或两种等位基因突变或线粒体突变,其中包括119名新生儿携带GJB2基因突变,93名新生儿携带SLC26A4基因突变,以及18名线粒体基因突变。这其中还包括2名新生儿为GJB2基因的纯合突变,1名新生儿携带SLC26A4杂合突变和12S rRNA1555A>G均质性突变,2名新生儿携带SLC26A4杂合突变和GJB2基因复合杂合突变。然而,有192例基因携带者通过了听力筛查。结论：通过对听力筛查结果的分析,总体的初筛率为97.4%,达到筛查工作要求的95%以上。基因筛查可以做为听力筛查的重要补充,不但能够弥补听力筛查中存在的局限性,提高聋儿的检出率,而且可以明确病因,通过对先证者分子病因学的诊断,有效的遗传咨询将对其家族成员的耳聋防治具有重要意义。将听力筛查和基因筛查联合应用于早期发现处于语前听力损失或迟发型高危患儿或者是致聋基因的携带者,并结合定期的随诊及监测,是目前最为有力的筛查策略。更多还原

【Abstract】 Objective:The aim of our study was to discuss and analyze the feasibility and effectiveness of combining newborn hearing screening with screening for genetic mutations associated with deafness in order to supply the defects or limitation in the hearing screening.Methods:Ten thousand forty-three newborn babies, born between December2009and April2011in Gansu province, China, were accepted the simultaneous hearing and gene screening. The otoacoustic emissions test (OAE) was used for the initial and retest hearing screening. The automatic auditory brainstem response test (AABR) was used for the diagnostic screening. The OAE test was used as the the initial test for infants of48-72h after birth. For high-risk infants, the initial test was completed for prior to discharge from the hospital when the infant’s health returned to normal. For those who were referred after the initial test, repeated tests of OAE plus AABR (automatic auditory brainstem response) were carried out for the42days. If infants did not pass the two-step screens, a series of diagnostic audiological tests should be administered to them before the age of3months. The Universal Newborn Genetic Screening Card (UNGSC) for collecting blood samples, designed by the Chinese People’s Liberation Army General Hospital, was adopted. The cards could be directly performed the polymerase chain reaction (PCR) for screening the mitochondrial12S rRNA and GJB2as well as SLC26A4genes mutations. All PCR positive products were verified by sequencing. The software of DNA Star was used to analysis the sequence.Results:In the hearing screening,9786newborns were accepted the first-step screening and the initial screening rate was97.4%(9786/10043).85.5%individuals passed the first-step hearing screening,7.5%(732/9786) babies passed only one side, and the other6.9%(677/9786) were bilaterally referred. The referral rate for hearing loss in the first-step screening was14.4%(1409/9786), decreasing significantly to3.8%(362/9506) upon retesting. After the second-step screening, a total of537newborns were lost to follow-up. The genetic screening found that about 2.29%(230/10043) individuals carried one or more recessive risk alleles or the mitochondrial mutation. Among them,18babies had the pathogenic mitochondrial DNA mutation,92babies were SLC26A4heterozygote carriers, one case with both SLC26A4and12S rRNA1555A>G mutation,117babies were GJB2heterozygote carriers, and two babies were GJB2homozygote carriers. However,83.5%(192/230) neonates passed the conventional hearing screening among these carriers.Conclusion:In conclusion, our study indicates that it would be effective and practical to complement the conventional audiological test in newborns with genetic screening for deafness predisposing genes. The addition of genetic screening as a complement to audiologic newborn screening will help identify infants with late-onset prelingual hearing loss. It might be one of the powerful strategy for adding the concept of newborn gene screening into the hearing screening for the purpose of early diagnosis and discovery the prelingual or the high risk as well as the pathogenic carriers. It was necessary to develop the national newborn gene screening into the process of newborn hearing screening.更多还原