应用QF-PCR和CNV-seq以及染色体核型分析检测羊水的染色体畸变及结果分析

目的评价定量荧光PCR(QF-PCR)在染色体畸变中诊断的准确性,探讨QF-PCR、基因组拷贝数变异测序(CNV-seq)和染色体核型分析(核型分析)这3种技术在染色体畸变的产前诊断中的应用价值以及多方法联合诊断的优势和必要性。方法采用QF-PCR检测106例产前筛查高风险孕妇的产前羊水的染色体畸变,同时使用CNV-seq(102例)及核型分析(4例)检测;统计QF-PCR与后两者之间的阳性符合率。结果在21、18、13、X、Y共5种染色体非整倍体检测方面,QF-PCR与CNV-seq及核型分析的阳性符合率均为100%。对于所有46条染色体畸变的检测,CNV-seq阳性但QF-PCR无法检出的共21例,其中20例微缺失或微重复均小于5 Mb,核型分析可能均无法检出。结论QF-PCR对5种染色体非整倍体的检测具有很高的准确性。QF-PCR结合CNV-seq,相互补充和印证,快速且覆盖面广,具有部分替代核型分析的潜力;多方法联合诊断对染色体畸变的检出具有很大的优势和必要性。     

Correlation between CD34 expression and chromosomal abnormalities but not clinical outcome in acute myeloid leukemia

The hemopoletic stem cell marker CD34 has been reported to be a useful predictor of treatment outcome in acute myeloid leukemia (AML). Previous data suggested that CD34 expression may be associated with other poor prognosis factors in AML such as undifferentiated leukemia, secondary AML (SAML), and clonal abnormalities involving chromosome 5 and 7. In order to analyze the correlations between the clinicopathologic features, cytogenetic and CD34 expression in AML, we retrospectively investigated 99 patients with newly diagnosed AML: 85 with de novo disease and 14 with secondary AML (SAML). Eighty-six patients who received the same induction chemotherapy were available for clinical outcome. Defining a case as positive when ≥ 20% of bone marrow cells collected at diagnosis expressed the CD34 antigen, forty-five patients were included in the CD34 positive group. Ninety patients had adequate cytogenetic analysis. Thirty-two patients (72%) with CD34 positive AML exhibited an abnormal karyotype whereas 15 patients (28%) with CD34 negative AML had abnormal metaphases (P < 0.01). Monosomy 7/7q- or monosomy 5/5q- occurred in 10 patients and 8 of them expressed the CD34 antigen (P < 0.05). All patients with t(8;21) which is considered as a favorable factor in AML had levels of CD34 ≥ 20% (P < 0.05). We did not find any association between CD34 expression and attainment of complete remission, overall survival, or disease-free survival. In conclusion, the variations of CD34 expression in AML are correlated with cytogenetic abnormalities associated both with poor and favorable outcome. The evaluation of the correlations between CD34 antigen and clinical outcome in AML should take into account the results of pretreatment karyotype. © 1996 Wiley-Liss, Inc.     

甲醛对人支气管上皮细胞系转化和染色体不稳定性影响的研究

目的为探讨化学致癌的机制,揭示恶性转化与染色体不稳定性之间的关系,本研究考察甲醛对人支气管上皮细胞系转化和染色体稳定性的影响.方法用甲醛作为诱导剂,以液体染毒后测定BEAS-2B细胞的LC50,以低剂量(20% LC50)对细胞进行诱导,观察细胞生长特性改变并筛选诱导克隆.然后用细胞遗传学方法(G带染色法)考察诱导细胞染色体畸变的情况.结果甲醛作用后细胞生长速度加快,且呈现无限增殖趋势.在后期(15代)具有很强的锚着独立性生长能力,表明诱导细胞已发生慢性转化.诱导细胞核型由2倍体转化为近2倍体、非整倍体和多倍体等核型同时存在,染色体稳定性降低,呈现丢失、内复制、易位、断裂、双/三着丝粒,并伴有大量非稳定性畸变. 结论甲醛可使BEAS-2B细胞发生转化,并影响细胞染色体的稳定性,使其发生畸变并向恶性化方向发展.     

早期异常报告系统在北京市朝阳区流行性感冒预警中的应用

目的 探索早期异常报告系统在北京市朝阳区流行性感冒(流感)预警中的应用效果,为流感防控提供科学依据.方法 选择2015年3月30日-2018年4月1日北京市朝阳区流感样病例(influenza-like illness,ILI)和流感病原学监测数据,用流感病原学监测数据确定朝阳区流感流行期的"金标准",用早期异常报告系...     

Prenatal diagnosis and molecular cytogenetic characterization of three chromosomal abnormalities with favorable outcomes

ObjectiveHere we present three cases of chromosomal abnormalities with favorable outcomes.Case reportIn Case 1, conventional karyotyping revealed a karyotype of 46, XY,t(7; 14) (q35; q13)[4]/46,XY[26]. Array comparative genomic hybridization (aCGH) analysis revealed no genomic imbalance. In Case 2, conventional karyotyping revealed a norma karyotype but aCGH analysis revealed a 3.2M chromosomal duplication (13q12.11q12.12(22, 073, 046_25, 230, 759)x3). In Case 3, aCGH analysis revealed a 5.5M chromosomal deletion (9q21.13q21.32 (78, 645, 382_84, 115, 555) x1). In all three cases, ultrasound examination showed no dysmorphisms and intrauterine growth restrictions (IUGRs) in the fetus. All three pregnancies resulted in phenotypically normal babies.ConclusionChromosomal abnormalities may be associated with favorable outcomes. Combining conventional karyotyping, aCGH analysis and ultrasound results can provide a more accurate risk assessment for pregnant women with advanced age.     

基因组时代产前诊断面临的机遇和挑战

        自20世纪70年代开始,染色体核型分析技术作为诊断胎儿染色体异常的金标准已使用多年,但该技术存在分辨率较低（5~10Mb）、培养周期长、检测通量低及有培养失败风险等局限性。随后,靶向诊断技术（FISH、QF-PCR、MLPA）的出现,大大缩短了检测时间,与染色体核型技术联合应用,可早期诊断常见的胎儿染色体异常。此外,Sanger测序作为基因变异检测的金标准,可用于明确致病的单基因疾病的产前诊断。然而,以上技术均无法实现在全基因组范围内进行快速、高分辨率地诊断胎儿致病性变异。 浏览更多请关注微信公众号及当期杂志。     

Wolf-Hirschhorn综合征4例及文献复习

目的　探讨Wolf-Hirschhorn综合征（WHS）临床特征及基因突变。方法　回顾分析2017-11-20—2018-05-26南京医科大学附属儿童医院收治的4例发育延迟及智力低下患儿的临床资料,临床拟诊为WHS。应用染色体微阵列芯片分析技术进行基因检测,并复习相关文献总结疾病特点。结果　2例男性和2例女性患儿因生后特殊面容（希腊头盔样面容）、智力低下、发育延迟、肌张力低下、癫痫,应用染色体微阵列芯片分析技术发现患儿4p16.3区域2.24～3.8 Mb的缺失,确诊WHS,给予抗癫痫及康复治疗并定期随访。结论　尽早完善染色体芯片技术检查有助于早期诊断WHS,且能判断预后。染色体微阵列芯片分析与传统细胞遗传学分析方法相比,具有高分辨和高准确度的优点,可为产前遗传学诊断提供更详细信息。     

13q13.3 microdeletion associated with apparently balanced translocation of 46,XX,t(7;13) suggests NBEA involvement

BackgroundDeletion of 13q13.3 is an extremely rare event.CaseWe report on a 25-month-old girl with neurodevelopmental disorder and intellectual disability. She had dysmorphic facies characterized by synophrys, long and narrow palpebral fissures; and a large, round face with small organs such as the eyes and mouth positioned near the center. She was hypotonic and had autism-like behaviors. Blood tests and brain MRI revealed no specific findings. However, G-banding chromosome analysis showed an apparently balanced translocation: 46,XX,t(7,13)(q11.23;q12.3). Both parents had normal karyotypes. Furthermore, her abnormal phenotype and chromosomal breakpoint lesion were suspected to be associated. Hence, we conducted array comparative genomic hybridization, which revealed a 3.2 Mb novel pathological microdeletion at 13q13.3 involving 17 genes including neurobeachin (NBEA), a neurodevelopment disorder gene. Furthermore, fluorescence in situ hybridization using probes adjacent to the microdeletion suggested a concomitant occurrence of the deletion and translocation as the structural basis of this rare genomic variant.ConclusionNBEA may have roles in her neurodevelopmental phenotypes, whereas other genes within the 13q13.3 microdeletion may contribute to her dysmorphic features.     

啤酒与乙醇对γ射线诱发小鼠骨髓细胞染色体畸变的影响

目的 观察啤酒及乙醇对不同剂量γ射线照射小鼠所诱发的骨髓细胞染色体畸变的影响.方法 雄性健康BALB/c小鼠,随机分成对照组、啤酒组和乙醇稀释液组,分别用1 ml灭菌生理盐水、啤酒及乙醇稀释液灌胃.30 min后给予不同剂量γ射线1次全身照射.照射后24 h颈椎离断法处死动物(处死前4 h按4 μg/g体重腹腔注射秋水仙胺),立即取双侧股骨,进行骨髓细胞常规染色体制片、染色.每一剂量点选取5个个体进行染色体畸变观察.每只动物镜检分析100个细胞分裂相.结果 啤酒组及乙醇稀释液组染色体畸变率在照射剂量达0.5 Gy以上时明显降低(P＜0.05或P＜0.01),其中啤酒组的下降比乙醇稀释液组更明显.结论 啤酒中除乙醇以外的其他成份(如酚类化合物等)也发挥了降低染色体畸变的作用.