Familial steroid-sensitive nephrotic syndrome in Southern Israel: clinical and genetic observations

Reports on genetically informative steroid-responsive (sensitive) idiopathic nephrotic syndrome (SSNS) families are lacking. We studied an extended SSNS Bedouin (B) family with a high rate of consanguinity. The clinical presentation and steroid response of its 11 affected individuals were similar to those of sporadic SSNS (spontaneous remission towards puberty and minimal change disease by kidney biopsy). Genome-wide linkage analysis, using a 382 microsatellite-markers mapping set and additional markers adjacent to 80 candidate genes of the index family, did not support linkage to any chromosomal locus. Retrospective analysis of all additional children with SSNS treated by our institution in the past 20 years (n = 96, 50% of them of Jewish origin) revealed another five non-related B families with 2–3 first-degree cousins affected with SSNS in each. The overall familial SSNS rate among the B population (excluding the index family) was 28%, compared with 4% among Jews (Js) (OR 1.8–64, P < 0.005). There were more Bs with simple SSNS than there were Js (71% and 40%, respectively; OR 3.58, 95% CI 1.41–9.23, P < 0.01). In summary, SSNS in this index family was not linked to any of the presently known chromosomal loci nor predicted to be caused by mutation in any one of a list of genes associated with nephrotic syndrome (NS). The presence of other B families affected by SSNS supports the role for susceptibility genes enrichment, exposing highly consanguineous populations to an increased incidence of SSNS. An erratum to this article can be found at     

冻融液的温度对人未成熟卵母细胞玻璃化冻融效果的影响

目的探讨冻融液的操作温度对未成熟人卵母细胞（GV、MI）玻璃化冻融效果的影响。方法收集卵胞浆内单精子注射（ICSI）患者的GV、MI卵母细胞,根据冻融液操作温度的不同分为A、B、C组。冻融后存活及未冷冻对照组（D组）卵母细胞体外成熟（IVM）培养,成熟的M11卵母细胞固定后进行免疫荧光染色,然后用NikonCISI激光扫描共聚焦显微镜观察纺锤体、染色体形态。结果实验组GA、GB、GC卵母细胞冻融后的存活率和体外成熟率分别为100％、81．3％、68．8％和33．3％、83．3％、72．7％,仅GC组的存活率与对照比较存在显著性的差异（P〈70．05）;实验组中只有GB组获得了纺锤体（20％）和染色体（10％）形态正常卵母细胞。实验组MA、MB、MC卵母细胞冻融后的存活率分别为71．4％、100％、83．3％,各实验组与对照组比较无显著性差异（P〉0．05）;MA组体外成熟率与对照组比较存在极显著性的差异（0％比57．1％,P〈0．01）,MB、MC与对照组的体外成熟率比较无显著性的差异（66．7％、80％比57．1％,P〉0．05）;仅MC获得1个正常纺锤体和染色体形态卵子。结论冻融液的合适操作温度可以提高未成熟卵子的冻融效果。     

染色体芯片检测下胎儿心脏发育异常与遗传学异常相关性

目的探讨研究染色体芯片检测下胎儿心脏发育异常与遗传学异常的相关性。方法选取2017年11月～2018年11月在本院接受产前检查显示异常的308例孕中期孕妇为研究对象,影像学检查心脏超声显示胎儿心脏发育异常孕妇18例为研究组,无胎儿心脏发育异常因高龄合并超声检查显示异常的290例孕妇为对照组,采集羊水行染色体核型分析和芯片分析。结果研究组胎儿复杂性心脏畸形15例,占83.33%,合并多发畸形3例,占16.67%;染色体异常3例,合并多发畸形1例,复杂性心脏畸形2例;芯片异常3例,合并多发畸形1例,复杂性心脏畸形2例。对照组胎儿正常78例,超声检查单发畸形178例,多发畸形34例,两组胎儿畸形率相比,差异有统计学意义(χ2=5.342,P=0.005);研究组染色体异常3例,占16.67%,对染色体正常的心脏发育异常胎儿进行芯片检查,芯片异常3例,芯片检查结果为10号染色体长臂末端片段缺失,对照组染色体均正常。结论胎儿心脏发育异常时合并遗传学异常几率增大,染色体芯片检测可有效诊断胎儿发育异常。     

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.     

RecQ helicase acts before RuvABC,RecG and XerC proteins during recombination in recBCD sbcBC mutants of Escherichia coli

The RecQ helicase is required by the RecF recombination pathway that is operative in recBC(D) sbcB sbcC(D) mutants of Escherichia coli. Genetic data suggest that RecQ participates in resection of DNA ends during initiation of recombination. In vitro, RecQ can unwind a variety of DNA substrates, including recombination intermediates such as D-loops and Holliday junctions. However, its potential role in processing of recombination intermediates during the late stage of the RecF pathway has not been genetically tested. Here we studied the effect of a recQ mutation on transductional recombination and DNA repair after γ-irradiation in ΔrecBCD ΔsbcB sbcC strains deficient for RuvABC, RecG and XerC proteins. RuvABC and RecG proteins process recombination intermediates in the late stage of recombination, whereas XerC is required to resolve chromosome dimers formed upon recombination. Our results do not reveal any substantial synergistic effect between the recQ mutation, on one hand, and ruvABC, recG and xerC mutations on the other. In addition, the recQ mutation suppresses chromosome segregation defects in γ-irradiated ruvABC recG and xerC mutants. These results suggest that RecQ acts upstream of RuvABC, RecG and XerC proteins, a finding that is compatible with its primary role in initiation of the RecF recombination pathway.     

MLPA技术在检测胎儿非整倍体异常中的应用

目的探讨多重探针连接依赖式扩增（multiplex ligation—dependent probe amplification,MLPA）在快速检测胎儿染色体非整倍体异常中的应用价值。方法344例产前诊断标本同时进行MLPA检测及核型分析,所有样本进行MLPA获得的扩增产物信息经Coffalyserv9．4软件（Holland—MRC公司）进行定量分析,观察样本DNA拷贝数的变化,并将所得结果与染色体核型分析结果进行比较,计算其检测的敏感度、特异度及阳性预测值。结果MLPA分析在标本接收后24h内即可得出结果,共检出染色体倍体异常产前诊断标本5例,包括唐氏综合征（Downsyndrome,47,＋21）6例、爱德华氏综合征（Edwardssyndrome,47,＋18）l例。MLPA检测24h报告结果临床符合率为97．7％。结论MLPA检测21、18、13、X、Y等染色体非整倍体疾病时,与核型分析相比较,MLPA是一种快速、高效的分析非整倍体的产前诊断的方法,具有临床应用价值。     

Could a patient with SMC1A duplication be classified as a human cohesinopathy?

The disorders caused by mutations in genes encoding subunits and accessory proteins of cohesin complex are collectively termed as cohesinopathies. The best known cohesinopathy is Cornelia de Lange Syndrome (CdLS), which is a multisystem developmental disorder characterized by facial dysmorphism, limb malformations, growth and cognitive impairment. Mutations in five genes, encoding subunits of the cohesin complex (SMC1A, SMC3, RAD21) and its regulators (NIPBL, HDAC8), are responsible for ～70% of CdLS cases. We describe a 16‐year‐old boy with facial dysmorphism, growth retardation, intellectual disability, hirsutism and small hands, who has a small Supernumerary Marker Chromosome (sSMC) present in mosaic form. sSMC is composed of two duplicated segments encompassing 17 genes including SMC1A gene, at the regions Xp11.22 and Xp11.21q11.1. Clinical comparison between our patient with a previously reported individual with a SMC1A duplication and four male carriers of similar sSMC reported in databases, suggest that they all share clinical features related to cohesinopathies. Although our patient does not have the classical CdLS craniofacial phenotype, he has pre and postnatal growth retardation, intellectual disability and mild musculoskeletal anomalies, features commonly seen in patients with cohesinopathies.     

180例孕中期胎儿羊水细胞染色体倒位的细胞遗传学分析

目的研究孕中期胎儿羊水染色体倒位与孕妇临床诊断之间的关系。方法通过对孕妇行羊膜腔穿刺,抽取羊水进行羊水细胞遗传学检查。胎儿染色体异常者需对父母进行外周血染色体检查。结果本实验室10364例羊水。共发现染色体倒位180例,其中9号染色体到位159例,占倒位总数的88．9％（159／180）,10例Y染色体倒位,占倒位总数的5．6％（10／180）,其余的倒位还涉及1、2、3、4、7、11、14、15、16、20号常染色体。结论不同的临床指针都有可能是胎儿染色体倒位。     

An update on ECARUCA,the European Cytogeneticists Association Register of Unbalanced Chromosome Aberrations

The European Cytogeneticists Association Register of Unbalanced Chromosome Aberrations (ECARUCA, www.ecaruca.net) is an online database initiated in 2003 that collects and provides detailed, curated clinical and molecular information on rare unbalanced chromosome aberrations. ECARUCA now contains over 4800 cases with a total of more than 6600 genetic aberrations and has over 3000 account holders worldwide. Recently, the ECARUCA web site was renewed, including the presentation of interesting case reports in collaboration with the European Journal of Medical Genetics. This article gives an overview of the current status and future plans of the online ECARUCA database.     

The psychological impact of cryptic chromosomal abnormalities diagnosis announcement

This qualitative study aims to describe the psychological impact of the diagnosis announcement of pathogenic Copy Number Variations (pCNVs). We performed semi-structured interviews of 60 parents of 41 affected children and 5 geneticists who announced the diagnoses. The diagnosis of the best characterized microdeletion syndromes, often defined by patronymic names (e.g. Williams syndrome), is generally made on a clinical basis by geneticists and confirmed by fluorescence in situ hybridization analysis. Chromosomal microarray, on the contrary, can allow the disclosure of rare pCNVs named after cytogenetic formulas, with poorly known clinical consequences: this makes doctors feel less confident with these diagnosis announcements. The disclosure of pCNVs named after cytogenetic formulas does not facilitate the parental mental representation of the disease, leading some parents to call into question the genotype-phenotype correlation or the very notion of a diagnosis. The announcement of inherited pCNVs can increase the feeling of parental guilt; the disclosure of de novo pCNVs can induce a feeling of “breakage” in the mental representation of the parent-child vertical transmission. In conclusion, our study shows that the disclosure of pCNVs has a significant psychological impact: a multidisciplinary approach to the diagnosis announcement, including a psychological support, should be systematically warranted.