不良孕产史夫妇染色体核型的大样本分析

目的探讨不良孕产史夫妇染色体异常核型检出率及其分布，以及染色体异常核型与不良孕产史的关系，为优生优育及遗传咨询提供理论依据。 方法选取2016年1月1日至2017年12月31日，于济南艾迪康医学检验中心进行染色体核型检测的10 330对(20 660例)不良孕产史育龄夫妇为研究对象。采集每例受试者肘静脉血3 mL，肝素钠抗凝，取0.3 mL进行血细胞培养、标本制备，采用常规G显带技术进行染色体核型分析。对于染色体异常核型检出率、不同类型染色体异常核型占染色体异常核型总例数的比例等计数资料，采用率(%)表示。本研究遵循的程序符合2013年修订的《世界医学协会赫尔辛基宣言》要求。 结果①本组10 330对(20 660例)不良孕产史育龄夫妇中，共计检出染色体异常核型为1 119例(不含染色体多态性)，染色体异常核型检出率为5.42%(1 119/20 660)。其中，常染色体异常者为658例，占染色体异常核型的58.80%(658/1 119)，包括354例染色体平衡易位、205例染色体倒位、83例染色体罗伯逊易位、11例染色体插入、5例染色体重复，分别占染色体异常核型的31.64%、18.32%、7.41%、0.98%、0.45%。染色体倒位者中，以9号染色体倒位居多，偶见于1、4、7、11、12号染色体，并且多合并自然流产。性染色体异常者为440例，占染色体异常核型的39.32%(440/1 119)，包括365例性染色体数目异常(占染色体异常核型的32.62%)。其中，男性多表现为无精子症，以47，XXY染色体异常核型居多(144例)，女性多表现为原发性不孕，以45，X染色体异常核型居多(103例); 61例为性染色体结构异常、14例为性别反转，分别占染色体异常核型的5.45%、1.25%。其他罕见染色体异常核型者为21例，占染色体异常核型的1.88%(21/1 119)，如环状染色体、mar染色体等。②本组10 330对(20 660例)不良孕产史育龄夫妇中，11例为常染色体插入，5例为常染色体重复，54例为性染色体缺失，其主要临床表现为原发性不孕不育、胚胎停止发育、无精子症或重度少精子症。 结论染色体异常核型是导致育龄期夫妇不良孕产史的重要原因之一。对于不良孕产史夫妇，建议进行染色体核型分析和遗传咨询。临床为这类患者进行优生优育指导，可提高出生人口质量。     

DNA excision repair and double-strand break repair gene polymorphisms and the level of chromosome aberration in children with long-term exposure to radon

Purpose: To study polymorphic variants of repair genes in people affected by long-term exposure to radon. The chromosome aberration frequency in peripheral blood lymphocytes was used as the biological marker of genotoxicity.

Materials and methods: Genotyping of 12 single nucleotide polymorphisms in DNA repair genes (APE, XRCC1, OGG1, ADPRT, XpC, XpD, XpG, Lig4 and NBS1) was performed in children with long-term resident exposure to radon. Quantification of the aberrations was performed using light microscopy.

Results: The total frequency of aberrations was increased in carriers of the G/G genotype for the XpD gene (rs13181) polymorphism in recessive model confirmed by the results of ROC-analysis (‘satisfactory predictor’, AUC?=?0.609). Single chromosome fragments frequency was increased in carriers of the G/G genotype in comparison with the T/T genotype. In respect to the total frequency of aberrations, the G/G genotype for the XpG gene (rs17655) polymorphism was also identified as a ‘satisfactory predictor’ (AUC?=?0.605). Carriers of the T/C genotype for the ADPRT gene (rs1136410) polymorphism were characterized by an increased level of single fragments relative to the T/T genotype.

Conclusion: The relationships with several types of cytogenetic damage suggest these three SNP (rs13181, rs17655 and rs1136410) may be considered radiosensitivity markers.     

Case of Chronic Lymphocytic Leukemia with Unusual Chromosome Aberrations

Chronic lymphocytic leukemia is one of the most common leukemias in the western world and consists of many chromosome aberrations. We report the case of a 74-year-old male patient with chronic lymphocytic leukemia with complex variant translocations t(8;22)(q24;q11) and der(8)t(6;8)(p21;p21) identified by chromosome banding analysis and confirmed by fluorescence in situ hybridization analysis of interphase cells. Because of the rarity of these changes, possible molecular mechanisms associated with this karyotype are discussed.     

胎儿颈项透明层厚度在产前诊断中的价值

目的 探讨彩超检测胎儿颈项透明层(nuchal translucency,NT)厚度与胎儿染色体异常、结构异常及妊娠结局的关系并分析其在产前诊断中的价值.方法 应用彩色多普勒超声诊断仪对孕11～13+6周的3 248例孕妇行经腹超声检查,测量胎儿NT值,记录孕妇不良妊娠结局,并随访至胎儿出生后6个月.结果不同年龄孕妇的胎儿NT值(F=0.089,P=0.976)及NT增厚率(x2=0.432,P=0.934)比较,差异均无统计学意义;不同NT值组染色体异常检出率(x2 =559.89,P＜0.001)及不良妊娠结局发生率(x2=494.27,P＜0.001)比较,差异有统计学意义.NT增厚组染色体异常检出率(x2=323.28,P＜0.001)及不良妊娠结局发生率(x2=270.66,P＜0.001)明显高于胎儿NT正常组.NT≥3.5 mm组染色体异常检出率(x2=6.46,P=0.011)及不良妊娠结局发生率(x2=9.99,P=0.002)明显高于2.5～3.5 mm组.结论 NT增厚在产前诊断中具有重要筛查意义,随着NT增厚,胎儿的染色体异常率及不良妊娠结局发生率均增高.     

Frequent loss of heterozygosity in two distinct regions,8p23.1 and 8p22, in hepatocellular carcinoma

AIM: To identify the precise location of putative tumor suppressor genes (TSGs) on the short arm of chromo- some 8 in patients with hepatocellular carcinoma (HCC). METHODS: We used 16 microsatellite markers informative in Japanese patients, which were selected from 61 pub- lished markers, on 8p, to analyze the frequency of loss of heterozygosity (LOH) in each region in 33 cases (56 lesions) of HCC. RESULTS: The frequency of LOH at 8p23.2-21 with at least one marker was 63% (20/32) in the informative cases. More specifically, the frequency of LOH at 8p23.2, 8p23.1, 8p22, and 8p21 was 6%, 52%, 47%, and 13% in HCC cases. The LOH was significantly more frequent at 8p23.1 and 8p22 than the average (52% vs 22%, P = 0.0008; and 47% vs 22%, P = 0.004, respectively) or others sites, such as 8p23.2 (52% vs 6%, P = 0.003; 47% vs 22%, P = 0.004) and 8p21 (52% vs 13%, P = 0.001; 47% vs 13%, P = 0.005) in liver cancer on the basis of cases. Notably, LOH frequency was significantly higher at D8S277, D8S503, D8S1130, D8S552, D8S254 and D8S258 than at the other sites. However, no allelic loss was detected at any marker on 8p in the lesions of nontumor liver tissues. CONCLUSION: Deletion of 8p, especially the loss of 8p23.1-22, is an important event in the initiation or promotion of HCC. Our results should be useful in identi- fying critical genes that might lie at 8p23.1-22.     

一个原发性痛风家系致病易感基因染色体定位

目的 对一原发性痛风家系进行致病基因的染色体定位。方法 收集痛风家系成员的临床资料及血液样本。选择其中一典型家系为研究对象（包括6例患者，9例正常人），抽提外周血基因组DNA，进行全基因组扫描和连锁分析，初步明确致病基因所在的染色体区段。结果 在微卫星引物D4S1572处获得最大LOD值（θ=0．00时LOD=1．50），表明该痛风家系的致病基因与该位点连锁。结论 由于D4S1572位于4q25，因此该家系致病基因位于4q25附近。     

Tdentification of a new target region on the long arm of chromosome 7 in gastric carcinoma by loss of heterozygosity

AIM: To define the common deleted region on the long arm of haman chromosome 7q linked to primary gastric carcinomas in Chinese by loss of heterozygosity (LOH)and its clinical significance.METHODS: Nine microsatellite markers distributed over chromosome 7q with an average marker density of 10cM were used to examine 70 primary gastric carcinomas for LOH by PCR amplification. The PCR products were separated by electrophoresis on polyacrylamide gel.Genescan and Genotyper soft-wares were used to analyze LOH.RESULTS: LOH with at least one marker on 7q occurred in 34.3% (12/50) of the tumors. Among them, LOH at D7S486 and D7S798 was higher in 24.0% (24/70) and 19.2% (5/26), respectively. By statistical analysis we also observed an obvious genotype-phenotype correlation on 7q (P＜0.05). The frequency of LOH at D7S486 in patients with lymph node metastasis was significantly higher than that in those without lymph node metastasis (P= 0.015).CONCLUSION: The high incidence of LOH at D7S486and its correlation with poorer prognosis suggest that there might be putative tumor suppressor genes in this region involved in the tumorigenesis and progression of gastric carcinoma.