Large duplication in LMBR1 gene in a large Chinese pedigree with triphalangeal thumb polysyndactyly syndrome

Polydactyly and syndactyly are digital abnormalities in limb‐associated birth defects usually caused by genetic disorders. In this study, a five‐generation Chinese pedigree was found with triphalangeal thumb polysyndactyly syndrome (TPTPS), showing an autosomal dominant pattern of inheritance. We utilized linkage analysis and whole genome sequencing (WGS) for the genetic diagnosis of this pedigree. Linkage analysis was performed using a genome‐wide single nucleotide polymorphism (SNP) chip and three genomic regions were identified in chromosomes 2, 6, and 7 with significant linkage signals. WGS discovered a copy number variation (CNV) mutation caused by a large duplication region at the tail of chromosome 7 located in exons 1–5 of the LMBR1 gene, including the zone of polarizing activity regulatory sequence (ZRS), with a length of approximately 180 kb. A real‐time polymerase chain reaction (PCR) assay confirmed the duplication. The findings of our study supported the notion that large duplications including the ZRS caused TPTPS. Our study showed that linkage analysis in combination with WGS could successfully identify the disease locus and causative mutation in TPTPS, which could help elucidate the molecular mechanisms and genotype–phenotype correlations in polydactyly.     

用分子克隆技术构建D12S391基因座等位基因分型标准物及群体遗传学研究

目的 解决长期困扰短串联重复序列（short tandem repeat,STR）分型上存在的准确性和标准化问题。方法 先用PCR扩增出D12S391基因座的9个等位基因片段，将其插入pUC重组质粒中，经DNA测序分析证实插入片段的结构及大小，用国际标准将插入的等位基因片段进行命名，最后经转染、扩大培养、扩增及再鉴定后，制备出标准的D12S391等位基因分型标准物。结果 应用此法制备出大量的D12S391基因座等位基因分型标准物，并将其用于调查该基因座在德国Mainz地区、日本Miyazaki地区及中国成都汉族、北京汉族、新疆维吾尔族和甘肃回族6个群体中的基因型分布频率。D12S391基因座在各群体中均有较高的多态性，其非父排除概念及个人识别能力分别为0.609-0.786和0.940-0.952。结论 该法制备的STR基因座等位基因分型标准物在法医科学实践中应用价值极高，D12S391基因座是一个非常适合于群体遗传学研究和法医科学应用的遗传标记。     

Genomic structure and eight novel exonic polymorphisms of the human N-cadherin gene

 Analysis of the detailed genomic structure of human N-cadherin revealed that the 16-exon gene is more than 72 kb in length and that it consists of a mosaic of exons. Five repeated cadherin domains, a transmembrane domain, and a cytoplasmic domain are encoded by exons 4 to 13, 13 and 14, and 14 to 16, respectively. A search for molecular variants in the entire coding region in 96 Japanese individuals resulted in the identification of eight sequence polymorphisms including three CCT- or GCC-type trinucleotide repeat polymorphisms adjacent to the initiation codon and five other novel single-nucleoticle polymorphisms (SNPs) in the coding region. Three of the five SNPs accompanied an amino acid substitution: Ala118Thr, Ala826Thr, and Asn845Ser. Knowlege of the fine gene structure and eight novel polymorphisms will be useful for the genetic study of the role of N-cadherin in diseases involving cell adhesion in the brain and in cardiomyocytes. Received: January 23, 2002 / Accepted: March 12, 2002     

BRAF copy number gains in thyroid tumors detected by fluorescence In Situ hybridization

Point mutation of the BRAF gene is a common genetic event in papillary thyroid carcinomas. More recently, it has been found that BRAF can also participate in chromosomal rearrangement. In this study, we explore yet another possible mechanism of BRAF alteration, which involves copy number gain. Using fluorescence in situ hybridization with BRAF specific and chromosome 7 centromeric probes, we studied 62 follicular thyroid tumors and 32 papillary carcinomas. We found that numerical changes in BRAF copy number were rare in papillary thyroid carcinomas, while they occurred in 16–45% of follicular tumors of conventional and oncocytic (Hürthle cell) types. They were due to amplification of the gene or gain of one or more copies of chromosome 7. Tetrasomy for chromosome 7 was overall the most common finding. The changes in BRAF copy number did not overlap with RAS mutations in follicular tumors. In a group of follicular carcinomas, tumors with BRAF copy number gain were significantly more often widely invasive (67%) compared to tumors with no copy number change (18%). By Western blotting, the tumors carrying four copies of the gene revealed higher expression of BRAF protein, suggesting that copy number gain may represent another mechanism of BRAF activation in thyroid tumors.     

Is the CAG repeat of mitochondrial DNA polymerase gamma (POLG) associated with male infertility? A multi-centre French study

BACKGROUND: Recent data emphasized the implication of polymerase gamma (POLG) CAG repeats in infertility, making it a very attractive gene for study. A comparison of POLG CAG repeats in infertile and fertile men showed a clear association between the absence of the usual 10-CAG allele and male infertility, excluding azoospermia. It has also been suggested that the POLG gene polymorphism should be considered as a possible contributing factor in unexplained couple infertility where semen parameters are normal. In this study, we investigated the POLG CAG repeats, in a well-defined population of patients with severe male factor infertility. METHODS: We conducted a large study of POLG CAG repeats in 433 infertile and 91 fertile, normozoospermic and healthy males. In all subjects, phenotypic data, including semen parameters, hormonal status and clinical profiles, were available. RESULTS: Thirteen 'homozygous mutants' (3%) were found among the 433 idiopathic infertile patients. The follow-up of the 13 'homozygous mutant' resulted in pregnancy for more than half of the couples, through assisted reproductive techniques or even spontaneously. In addition, one 'homozygous mutant' was identified in 91 fertile men (1.1%) CONCLUSION: Under our conditions, our study does not confirm any relationship between the polymorphic CAG repeat in the POLG gene and male infertility.     

潮汕地区汉族人群9个新Y-STR基因座多态性研究

目的 分析9个新Y染色体短串联重复序列(Y short tandem repeats,Y-STR)基因座的序列结构,及其在潮汕地区汉族人群中的遗传多态性分布,评价其法医学应用价值.方法 应用PCR反应,对潮汕地区汉族159名无关男性个体的血样进行基因分型,采用直接计数法计算9个Y-STR基因座的等位基因频率和单体型频率.结果 9个Y-STR基因座(DYS522、DYS549、DYS556、DYS565、DYS568、DYS570、DYS594、DYS593、DYS588)均为单拷贝,并分别检测出7、5、5、4、6、9、4、4、8个等位基因,基因多样性(gene diversity,GD)在0.1434～0.7994间;共检出136种单体型;累计单体型GD值为0.997.另对30个2代父子家系调查显示:同一家系成员9个Y-STR基因座单体型一致,未观察到基因突变.结论 9个Y-STR基因座具有较高的鉴别效能,适合作为法医学应用的遗传标记.     

Alteration of E-cadherin-mediated adhesion protein is common,but microsatellite instability is uncommon in young age gastric cancers

AIMS: Gastric adenocarcinoma in young patients has been considered to differ in many ways from gastric carcinoma in older patients. This study was designed to determine the clinicopathological features and molecular mechanisms. METHODS AND RESULTS: Based on 4123 patients of gastric cancer in Seoul National University Hospital, 135 patients (3.3%) were chosen by the age of 30 years or younger. Expression of E-cadherin, beta-catenin, p53 and Epstein-Barr virus (EBV) was analysed using the tissue array method in formalin-fixed paraffin-embedded specimens and microsatellite instability (MSI) was determined. As a control, 320 cases of older patients were compared. Gastric adenocarcinoma of young patients revealed significant female predominance, type IV gross type, proximal location, diffuse type and frequent lymph node metastasis. In-situ hybridization for EBV showed higher positivity in young patients (9/78, 11.5%) than in older ones, but not statistically significant. In EBV+ cases, p53 over-expression was significantly higher in young patients than older patients (P < 0.05). Alteration of E-cadherin or beta-catenin was significantly higher in younger patients than in older patients (P < 0.05). Overall survival was significantly poorer in younger patients than older ones. The frequency of MSI was rare (1.3%, P < 0.05) in young patients compared with older patients (9.3%). CONCLUSIONS: These data indicate that gastric adenocarcinoma of young patients has a poor prognosis, possesses aggressive histopathological features, exhibits reduced expression of E-cadherin and beta-catenin, and demonstrates lower MSI than tumours in older patients.     

The specificity of the response of preoptic-septal area neurons to estrogen: 17α-estradiol versus 17β-estradiol and the response of extrahypothalamic neurons

Summary The purpose of this study was to determine the specificity of the response of medial preoptic-septal neurons (mPOA-S) to microelectrophoresed 17-estradiol hemisuccinate (17E₂S). In vitro studies were conducted initially to determine the release of the labeled 17E₂S from multibarrel glass micropipettes. Subsequently, an isomer of 17E₂S, 17-estradiol hemisuccinate (17E₂S), was synthesized and purified. Thirty-six mPOA-S neurons from normal cycling female rats were tested with both 17E₂S and 17E₂S. Twelve of these units responded with inhibition to 17E₂S, while none responded to 17E₂S. Furthermore, fifty extrahypothalamic (cortical, hippocampal, thalamic) neurons were tested with 17E₂S. The majority (N = 45) showed no response, three showed excitation and two inhibition to the microelectrophoresed steroid ester. These findings suggest that a specific receptor mechanism is responsible for the changes in mPOA-S unit activity, and that these effects may be important in the regulation of reproductive events.Supported by NIH Grant NS10434-END, awarded to R.L. MossPresently an NIH Postdoctoral Fellow at Max-Planck Institute for Biophysical Chemistry, Göttingen, West GermanyRecipient of an USPHS Career Development Award No. HD00146     

Sympathetic neurons in the superior cervical ganglion are more numerous in SHR and Wistar-Kyoto rats than in wistar rats

Department of Physiology of Man and Animals, Faculty of Biology, Moscow University. Laboratory of Pathophysiology, Research Institue of Pediatrics, Academy of Medical Sciences of the USSR. Department of General Biology, N. I. Pirogov Second Moscow Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR M. Ya. Studenikin.) Translated from Byullet en' Éksperimental'noi Biologii i Meditsiny, Vol. 108, No. 11, pp. 620–622, November, 1989.     

Iα1基因hs1,2 区B等位基因与IgA肾病的易感性相关

［摘要］ 目的：研究Iα1 hs1,2 VNTR多态性与我国IgA肾病的相关关系。 方法： 采集419例肾活检证实的IgA肾病患者及其一级亲属、条件相当的201例健康志愿者血样，提取基因组DNA。用PCR产物直接电泳法鉴定Iα1 hs1,2 VNTR基因型，采用以家庭为基础的传递/不平衡分析（TDT）和单倍型相对危险度（HRR），以及病例-对照研究分析Iα1 hs1,2 VNTR多态性与我国IgA肾病的相关关系。 结果： ① TDT分析结果显示Iα1 hs1,2 VNTR B等位基因从杂合子父母向患者传递的频率显著高于预期值(101 Trios, χ2=6.818, P＜0.01，扩展TDT分析也得到相同结果(164家庭, χ2=7.583, P＜0.01)。②与TDT结果一致，HRR分析同样显示Iα1 hs1,2 VNTR B等位基因的过度传递 (P＜0.05, χ2=4.122, HRR=1.180)， 而BB基因型具有更强的患病倾向 (P＜0.05, χ2=4.411, OR=1.538)。③病例-对照研究显示IgA肾病组B 等位基因频率显著高于正常对照组(χ2=6.968, P＜0.05)。 结论： Iα1 hs1,2 VNTR基因多态性与我国IgA肾病患者的易感性相关。