基于社区水平的珠海市大人群地中海贫血的遗传筛查和产前诊断

目的 阐述在广东省珠海市开展基于社区的控制重型α和β地中海贫血(简称地贫)的预防模式.方法 构建由6家医院组成的二级地贫遗传服务网络,以珠海市婚前医学或产前检查人群作为筛查对象,采用常规杂合子筛查策略,以标准的血液学分析流程进行α和β地贫特征的筛查.对所有地贫疑诊对象进行随访和遗传咨询,并采用基于PCR的分子诊断技术对高风险夫妇进行确诊.在知情同意和选择的情况下,对高风险妊娠实施产前基因诊断并通过选择性引产淘汰受累的重型地贫胎儿.结果 从1998年1月至2005年12月,共筛查了85522例拟婚育龄青年和10439例孕妇,婚检地贫筛查覆盖率达到71.38%.在6563例地贫筛查阳性的病例中,α和β地贫分别为4312例(4.5%)和2251例(2.3%);总计发现148对有生育重型地贫儿可能的高风险夫妇(α地贫103对,β地贫45对),其中有142对(95.9%)高风险夫妇进行了产前诊断(α地贫98例,β地贫44例).本项目启动后共减少了41例重型地贫患儿的出生,其中包括Hb Barts水肿胎23例、Hb H病4例和重型β-地贫14例.结论 这是我国首次基于社区水平的、在拥有129万人口的珠海市实施的前瞻性α和β地贫预防监控计划.这一预防模式对我国其他地贫高发区和其他发展中国家开展地贫和其他血红蛋白病的预防有着重要的借鉴意义.     

Experience with carrier screening and prenatal diagnosis for 16 Ashkenazi Jewish genetic diseases

The success of prenatal carrier screening as a disease prevention strategy in the Ashkenazi Jewish (AJ) population has driven the expansion of screening panels as disease‐causing founder mutations have been identified. However, the carrier frequencies of many of these mutations have not been reported in large AJ cohorts. We determined the carrier frequencies of over 100 mutations for 16 recessive disorders in the New York metropolitan area AJ population. Among the 100% AJ‐descended individuals, screening for 16 disorders resulted in ～1 in 3.3 being a carrier for one disease and ～1 in 24 for two diseases. The carrier frequencies ranged from 0.066 (1 in 15.2; Gaucher disease) to 0.006 (1 in 168; nemaline myopathy), which averaged ～15% higher than those for all screenees. Importantly, over 95% of screenees chose to be screened for all possible AJ diseases, including disorders with lower carrier frequencies and/or detectability. Carrier screening also identified rare individuals homozygous for disease‐causing mutations who had previously unrecognized clinical manifestations. Additionally, prenatal testing results and experience for all 16 disorders (n = 574) are reported. Together, these data indicate the general acceptance, carrier frequencies, and prenatal testing results for an expanded panel of 16 diseases in the AJ population. Hum Mutat 31:1–11, 2010. © 2010 Wiley‐Liss, Inc.     

无创产前筛查技术在产前筛查与诊断技术体系中的效能分析

目的:评价无创产前检测(non-invasive prenatal testing,NIPT)技术在产前筛查中的效能及其在产前诊断体系中的作用。方法:对22 649例单胎孕妇的产前筛查结果及诊断路径进行效能分析。对同期接受介入性产前诊断的9268例本院和转诊孕妇的指征及结局进行效能分析。结果:孕妇选择唐筛比例为60.2...     

Cystic fibrosis: community knowledge and attitudes towards carrier screening and prenatal diagnosis

The rate of technical advance in genetics contrasts sharply with the slow diffusion of information on this subject to the general population. In this paper, we investigate the initial knowledge about cystic fibrosis of a group of adults with increased interest in psychosocial issues, but with no special pre-existing knowledge or training in genetics. Attitudes towards carrier screening and prenatal diagnosis for CF were also evaluated, after brief written information had been given on this disease. We found that the studied group had only a poor knowledge of the nature of CF and an even more limited awareness of its inheritance. This knowledge was mainly associated with educational level. Most respondents had no objections to population-wide carrier screening for CF, at least if the test was proposed and not systematically imposed by the government. It is striking that a smaller proportion were interested in knowing their own carrier status. The majority of the group were in favour of prenatal diagnosis for CF. Factors associated with knowledge and attitudes are described. In the discussion, special attention is paid to the psychosocial complexity of mass screening.     

佛山地区产前筛查与产前诊断分析研究

目的佛山地区产前筛查与产前诊断分析研究。方法选择自2006年1月～2008年12月来本院进行产前检查的孕妇共41 656例,其中有2 9101例自愿行血清学筛查,孕周为15～25周,年龄21～42岁,平均年龄为25.73岁。有41 333例行超声筛查,孕周11～36周。对唐氏筛查及B超筛查结果为高风险的孕妇进行遗传咨询,建议进行产前诊断确诊。产前诊断的方法采用羊膜腔穿刺羊水细胞培养或经腹脐静脉穿刺脐血细胞培养,染色体检查采用G带染色。结果在血清筛查2 9101例孕妇中,筛查出高风险3227例,阳性率为11.1%。其中21三体高风险1287例,占4.4%;18三体高风险423例,占1.45%。在血清筛查高风险的3227例孕妇中,接受产前诊断者1065例,占33%（1065/3227）。染色体核型异常者100例,占12.49%,占高风险孕妇的4.12%（100/3227）。其中21三体19例,18三体2例,检出率为1.97%（21/1065）,占染色体核型异常的21%（21/100）。有41 333例行超声筛查,超声检查筛查出高风险851例,阳性率为2.06%。行产前诊断206例,染色体异常45例,占21.84%（45/206）,其中检查出21三体5例,18三体8例,13三体1例,占染色体异常的31.11%（14/45）。结论将孕妇年龄、血清学检测和超声筛查作为产前筛查唐氏综合征的方法,明显提高了筛查阳性率,通过产前筛查将高风险的人群筛查出来作产前诊断,减少了缺陷儿出生。     

Cystic fibrosis in Greece: molecular diagnosis,haplotypes, prenatal diagnosis and carrier identification amongst high-risk individuals

Cystic fibrosis (CF) mutation analysis on 437 CF patients, characterized 80 different mutations (20 so far specific to our population) accounting for 91% of CF genes and generating 103 different genotypes. Eight mutations were common [F508del (53.4%), 621+1G>T (5.7%), G542X (3.9%), N1303K (2.6%), 2789+5G>A (1.7%), 2183AA>G (1.4%), E822X (1.4%), R1158X (1%)], 12 showed frequencies between 0.5% and 1%, while the remaining (60) were very rare (1 to 3 alleles). Denaturing gradient gel electrophoresis (DGGE) screening of 12 exons (3, 4, 7, 10, 11, 13, 14b, 16, 17b 20 and 21) detected 85.5% of CF alleles. Haplotypes for eight diallelic and three microsatellite markers have been characterized for the common, a few rare and novel Greek mutations. Results of 165 prenatal diagnoses (including 49 due to bowel hyperechogenicity), testing a total of 41 different parental genotypes, are reported. One hundred and sixteen prenatal tests resulted in 22 affected, 59 heterozygous, 34 normal fetuses and one incomplete diagnosis. Of the 49 echogenic bowel fetuses, 3 were heterozygotes. Carrier screening was initiated, with emphasis on individuals and couples in high-risk groups - with a family history of CF, one partner with CF, and couples with male infertility seeking in vitro fertilization (IVF). Mutation analysis on 672 individuals (120 couples, 91 unaffected CF siblings, 283 CF family relatives and 58 general population subjects), identified a total of 176 heterozygotes and 7 couples where both partners were CF heterozygotes. Prenatal diagnosis was performed in 4 cases and 3 were counseled on the availability of a prenatal test.     

Noninvasive prenatal screening for RHD: the Stockholm study

The non-invasive technique to determine fetal RHD status opens the opportunity to change the antenatal screening and Rh-prophylaxis programs. During the period September 2009 to December 2011, we performed a study in the Stockholm area with approximately 27000 pregnancies per year. The study included routine cell free fetal DNA (cffDNA) RHD genotyping in early pregnancy followed by targeted RAADP in gestational week 29 to all RhD negative pregnant women carrying an RHD positive fetus. The new approach in our strategy, compared to previous studies, was that fetal RHD screening was done in early pregnancy at the first antenatal visit and based on a single-exon 4 assay. The implementation of this new screening program in a routine clinical setting is described. The final results of the study are still under analysis. The conclusion until now is that fetal RHD screening in early pregnancy is feasible and accurate with a high sensitivity and specificity, provided samples before gestational week eight were excluded.     

The centralized prenatal genetics screening program of New York City: II. Establishment of prenatal diagnosis laboratory

Prenatal diagnosis of genetic disorders is now being made available to an increasing number of New York City women through the establishment of a large centralized laboratory. This laboratory contracts to provide genetic diagnostic services to municipal and private hospitals throughout the New York City area. It is the first project of such magnitude in the United States. Prior to the receipt of samples for diagnostic purposes, the laboratory was required to meet the highest technical standards, as established by a Cytogenetics Advisory Committee. A set of guidelines was drawn up detailing the procedure and protocols for all the analyses and the reporting of results, including a timetable according to which results were to be obtained. The Cytogenetics Advisory Committee continues to review cases on a regular schedule. One of the unique aspects of the laboratory has been the development of back-up agreements with other area laboratories to assist in dealing with any problem that might disrupt the routine diagnostic service. The first year of operation of the laboratory has shown that financial, legal, and physical problems associated with designing and instituting a megacenter can be overcome. Similar programs should be encouraged.     

Practical guide to the diagnosis of thalassemia

Thalassemias occur in individuals of all ethnic backgrounds and are among the most common genetic diseases worldwide. The diagnosis of thalassemia can easily be part of primary medical practice. Here we outline a practical approach to the detection of thalassemias in three common clinical settings. The first involves any patient with a low mean corpuscular volume (MCV) with or without anemia. The second is a neonatal screening result indicating possible presence of thalassemia. Finally, evaluation for thalassemia should be considered in the context of family planning or pregnancy in patients whose ethnicity indicates origin from high risk geographic areas. We also review the various types of the thalassemia syndromes and provide an overview of general therapeutic considerations. © 1996 Wiley-Liss, Inc.     

出生缺陷产前筛查及产前诊断研究进展

出生缺陷已成为世界婴儿死亡、儿童和成人残疾的主要原因之一,是目前全世界关注的一个重大公共卫生问题。出生缺陷由遗传因素、环境致畸因素或两者共同作用所致。我国是出生缺陷高发国家,通过早期诊断、早期干预可以避免至少70%出生缺陷。出生缺陷干预是一个系统工程,产前筛查和产前诊断是胎儿出生缺陷干预的有效手段,是出生缺陷干预二级预防中的重要组成部分。     

有汗型外胚层发育不良一家系的Cx30基因突变检测及产前诊断

目的对一个中国汉族有汗型外胚层发育不良（hidrotic ectodermal dysplasis，HED）家系进行了突变筛查，并在此基础上对该家系中已孕5个月的胎儿进行了产前诊断。方法共收集了该家系2例患者及4名正常人的外周血标本，抽取了胎儿的脐血标本。扩增Cx30基因的整个编码区序列，直接双向测序，突变进一步经内切酶酶切分析验证，在成功地获得基因诊断结果后，进一步进行产前诊断。首先从脐血DNA标本中扩出Cx30基因的整个编码区序列，经内切酶酶切分析检测突变，并进一步将整个编码区序列克隆入T载体，测序验证突变。结果在两个受累患者中检测了相同的突变，即在Cx30基因存在一个263C→T的点突变，该突变导致了在GJB6蛋白第2个跨膜区中氨基酸残基改变（A88V）。胎儿的检测结果表明其基因组中同样存在该致病突变，因此是1个受累胎儿。结论实验数据表明Cx30基因中错义突变A88V也是中国汉族人群中有汗型外胚层发育不良的致病原因之一，可以通过基因诊断和产前诊断阻止致病基因的传递。     

Transcervical cells and the prenatal diagnosis of haemoglobin (Hb) mutations

Prenatal diagnoses of haemoglobin (Hb) mutations were performed using transcervical cells, retrieved by aspiration from the endocervical canal of ten selected pregnant women at about 10 weeks of gestation, prior to chorionic villus sampling (CVS). Both parents were carriers of haemoglobinopathies (thalassaemia or HbS). Clumps of fetal cells were isolated by micromanipulation under an inverted microscope and aliquots of the extracted DNA tested separately for the presence of paternally derived chromosome markers and Hb mutations by quantitative fluorescent polymerase chain reaction (PCR). The correct prenatal diagnosis of Hb diseases, using selected single clumps of trophoblastic cellular elements free of maternal contaminating cells, was achieved in six out of ten cases.     

唐氏综合征孕中期产前筛查及产前诊断的临床价值

目的探讨唐氏综合征的产前筛查和产前诊断在预防出生缺陷中的价值。方法对68813例孕15-20w的孕妇采用时间分辨荧光免疫方法检测血清AFP和B-HCG浓度,通过Maiticale软件计算危险系数,对唐氏高危和18-三体高危孕妇取羊水获脐血作染色体诊断,对神经管缺陷（NTD）高危孕妇行系统超声检查。结果筛查68813例孕妇,其中2632例为唐氏综合征或18-三体综合征高分险病例,占总筛查人数的3.82%;NTD高风险542例,占0.79%。接受羊水或脐血染色体检查1772例（占总阳性数的67.32%）,检出异常核型67例,占异常发生率3.78%;NTD高风险行超声检查证实胎儿畸形58例,占筛查高危孕妇的10.7%。结论孕中期产前筛查结合产前诊断可以有效预防出生缺陷的发生。     

江苏地区以人群为基础的唐氏综合征产前筛查和诊断研究

目的 对江苏省中期妊娠孕妇的胎儿进行唐氏综合征筛查和诊断,减少21三体综合征患儿出生.方法 用分层和整群抽样相结合的多阶段抽样方法,对江苏省怀孕15～20周的26 803名妇女采用时间荧光分辨法进行母血清常规二联筛查,筛查出的高风险孕妇进行羊膜腔穿刺、细胞培养、染色体分析.出生儿童通过面访和外周血染色体培养确诊.结果 血清筛查和羊水染色体检查,确诊6例胎儿;出生儿童随访和外周血染色体分析确诊3例,共确诊9例唐氏综合征,产前筛查检出率为67%(6/9).结论 产前筛查和诊断可以减少唐氏综合征患儿出生,提高出生人口素质.但是应提高产前筛查的准确性,最大限度地降低假阴性,减少或杜绝漏诊发生.     

Feasibility of DNA based methods for prenatal diagnosis and carrier detection of propionic acidaemia

Propionic acidaemia (PA) is an autosomal recessive disease caused by a genetic deficiency of propionyl-CoA carboxylase (PCC). Defects in the PCCA and PCCB genes that code for the alpha and beta subunits of PCC, respectively, are responsible for PA. A proband with PA was previously shown to carry the c1170insT mutation and the private L519P mutation in the PCCB gene. Here we report the prenatal diagnosis of an affected fetus based on DNA analysis in chorionic villus tissue. We have also assessed the carrier status in this PCCB deficient family, which was not possible with biochemical analysis.     

Noninvasive prenatal screening (NIPS) for fetal chromosome abnormalities in a general-risk population: An evidence-based clinical guideline of the American College of Medical Genetics and Genomics (ACMG)

PurposeThis workgroup aimed to develop an evidence-based clinical practice guideline for the use of noninvasive prenatal screening (NIPS) for pregnant individuals at general risk for fetal trisomy 21, trisomy 18, or trisomy 13 and to evaluate the utility of NIPS for other chromosomal disorders.MethodsThe NIPS Evidence-Based Guideline Work Group (n = 7) relied on the results from the recent American College of Medical Genetics and Genomics (ACMG) systematic review to form the evidentiary basis of this guideline. Workgroup members used the Grading of Recommendations Assessment, Development, and Evaluation Evidence to Decision framework to draft recommendations. The guideline underwent extensive internal and external peer review with a public comment period before approval by the ACMG Board of Directors.ResultsEvidence consistently demonstrated improved accuracy of NIPS compared with traditional screening methods for trisomies 21, 18, and 13 in singleton and twin gestations. Identification of rare autosomal trisomies and other microdeletion syndromes with NIPS is an emerging area of interest.ConclusionACMG strongly recommends NIPS over traditional screening methods for all pregnant patients with singleton and twin gestations for fetal trisomies 21, 18, and 13 and strongly recommends NIPS be offered to patients to screen for fetal sex chromosome aneuploidy.     

应用变性高效液相色谱技术进行肝豆状核变性的基因突变筛查及产前诊断

目的 探讨变性高效液相色谱(denature high performance liquid chromatography,DHPLC)技术在肝豆状核变性(Wilson's disease,WD)的突变筛查及产前诊断中的临床应用.方法 以6个WD家系中的患者及其父母的DNA为模板,采用PCR技术扩增ATP7B基因的21个外显子及5'非翻译区,PCR产物经DHPLC技术进行突变筛查,对峰型有改变者进行测序验证.在确定了先证者突变类型的基础上,采用相同方法对其中4个家系(1个双胎和3个单胎)进行产前诊断.结果 6例患者中检测出5种已知的致病突变及8种多态类型.患者的父母均为相应突变类型的携带者.产前诊断结果显示,两例妊娠为异常胎儿,其中1例双胎为Arg778Leu/IVS4-1G>C双重杂合子,1例单胎为Ser975Tyr/Pro992Leu双重杂合子,这两对妊娠夫妇选择了终止妊娠.另两例妊娠中,1例为Ser975Tyr杂合子,1例完全正常,他们选择了继续妊娠,出生了表型正常儿.结论 DHPLC在Wilson病的突变检测和产前诊断中有良好的应用前景.