Endothelial Nitric Oxide Synthase Gene Intron 4 (VNTR) Polymorphism and Vascular Access Graft Thrombosis

Vascular access thrombosis is a leading cause of vascular access failure in hemodialysis patients. Thrombosis is a multifactorial condition and genetic makeup can affect thrombosis risk. We conducted a study to investigate for possible associations between ecNOS gene intron 4 variable-number tandem repeat (VNTR) polymorphism and thrombosis of polytetrafluoroethylene hemodialysis arteriovenous access grafts (AVG) in Turkish patients. Fifty-five patients with end-stage renal disease who had AVGs implanted between 2000 and 2002 and 167 healthy individuals representing our healthy population were enrolled in this prospective study. Each subject provided a venous blood sample from which DNA was isolated, and polymerase chain reaction analysis was done to identify genotypes (aa, bb, ab) for ecNOS gene intron 4 VNTR polymorphism. All grafts were placed in brachioaxillary position. The subjects were divided into two groups based on duration of graft patency. The thrombosis group (Group I) comprised 26 patients who developed AVG thrombosis in the first 12 months after placement. The no-thrombosis group (Group II) comprised 29 patients whose grafts remained patient for at least 12 months. The frequency of the aa genotype in Group I was significantly higher than that in Group II (p =. 005). At 6, 12, and 24 months, the primary patency rates for the AVGs in patients with the aa genotype were significantly lower than the corresponding rates for the bb and ab genotype groupings (p =. 01, p =. 01 and p =. 04 for the three respective time points; Kaplan–Meier). ecNOS gene intron 4 VNTR polymorphism is linked with the pathogenesis of vascular access thrombosis in Turkish patients undergoing hemodialysis.     

刚地弓形虫醛缩酶基因及其内含子的分析

目的刚地弓形虫醛缩酶是其速殖子入侵宿主细胞过程中的一个重要分子，本研究对该酶基因序列及其内含子进行实验和分析。方法提取刚地弓形虫RH株速殖子基因组DNA和总RNA，采用PCR技术分别从基因组DNA和cDNA中扩增编码果糖1，6-二磷酸醛缩酶的基因，并克隆到T载体上，经测序鉴定后对其基因组序列和eDNA序列进行比较分析。通过NCBI数据库资源对醛缩酶内含子的分布及大小进行比较分析。结果根据醛缩酶基因设计的引物从基因组DNA扩增得到的片段长度为1315bp，从eDNA扩增得到的片段为993bp。比对结果显示来源于基因组DNA的序列在对应于编码序列起始密码子下游109bp后有一个322bp的内含子。通过在线工具收集得到NCBI及EMBL数据库中来源于不同物种的32种醛缩酶数据，分析显示推断氨基酸序列具有保守性。结论编码刚地弓形虫(Toxoplasma gondii)RH株果糖1，6-二磷酸醛缩酶基因编码区内存在一个322bp的内含子。醛缩酶氨基酸序列保守性较高。内含子在不同进化等级之间插入位置数目及大小两方面均存在明显的增加趋势。     

An analysis of the human chemokine CXC receptor 4 gene

In this article we analyze some of the structural characteristics of the coding section and the intron of the human chemokine CXC receptor 4 (a 7-transmembrane receptor) pre-mRNA. In the coding sequence the frequencies of the individual nucleotides do not depart significantly from 0.25, while in the intron the frequencies of the As and Gs are significantly lower and higher, respectively, than expected from a random distribution. Analysis of the pattern of association of nucleotides into triplets or couples shows that some triplets or couples occur with frequencies significantly higher or lower than expected when assuming a random association of nucleotides. In particular, in the intron combinations of the same nucleotide are over-represented. 7-or-more nucleotide repeats occur in both the coding section and the intron with frequencies which exceed the confidence limits for a random distribution. For the coding sequence this is possibly explained by the alternans of relatively similar hydrophobic-coding sections and relatively similar intervening intracellular and extracellular hydrophilic-coding sections. 7-or-more nucleotide repeats in reverse order and in reverse/complemented order occur in the intron, but not in the coding section, with frequencies which significantly exceed a random distribution. The numerous intronic repeats in reverse/complemented order may be of relevance for the secondary structure of the intron and might be one important element of the integrated splicing code.     

重型血友病A凝血因子Ⅷ第1内含子倒位的基因检测

目的 在中国重型血友病A(haemophilia A,HA)患者中筛查凝血因子Ⅶ(factor Ⅷ,FⅧ)基因第1内含子倒位,并对受累患者家系成员行携带者检查和产前基因诊断.方法 对重型HA患者(F Ⅷ:C<1%)采用长距离PCR法首先筛查第22内含子倒位,对第22内含子倒位阴性的应用双管多重PCR法进行第1内含子倒位检测,对第1内含子倒位阳性患者的女性家属进行携带者检测,对女性携带者所孕胎儿进行产前检测.用基因连锁分析和DNA测序法加以验证.结果 从247例重型HA患者中共检测出118例第22内含子倒位和7例第1内含子倒位,第1内含子倒位突变在中国重型HA人群中的发病率约为2.8%;随访到的两个受累患者家系A和B中各检出6名和2名女性携带者,家系A中产前检出1名第1内含子倒位受累胎儿.结论 采用双管多重PCR法可以直接检测凝血因子Ⅷ第1内含子倒位突变,完善了重型血友病A家系携带者检测和产前诊断.     

TSHR基因内含子1区域多态性与Graves病的关联研究

目的 探讨中国江苏徐州地区汉族人群促甲状腺素受体(TSHR)基因内含子1 上单核苷酸多态性位点(SNP)rs179247和rs12101261与Graves病的关系.方法应用TaqMan探针技术,在Fluidigm EP1平台上对1 066例Graves病患者和1 107名健康对照者进行基因分型;同时检测样本血清甲状腺激素和TSH受体抗体(TRAb)水平.结果 rs179247_A、rs12101261_T与Graves病易感性关联(分别为OR=1.35,95%CI 1.19～1.54,P=5.92×10-6;OR=1.32,95%CI 1.16～1.50,P=2.22×10-5);Logistic回归提示rs179247是独立的易感位点.在rs179247_GG、AG、AA 3种基因型之间相比,血清TRAb水平具有统计学差异(P=0.015);其他临床表现其差异均无统计学意义(P＞0.05).结论 TSHR基因内含子1区域rs179247、rs12101261与徐州地区汉族人群Graves病相关联,并且rs179247是一个独立易感位点;该多态性与血清TRAb水平有关,与血清甲状腺激素水平、发病年龄、甲状腺肿大程度、Graves病眼征分级、复发与否无明显关联.

Abstract：

Objective To investigate the association between polymorphisms of thyroid-stimulating hormone receptor(TSHR)gene intron 1(rs179247, rs12101261)and Graves′ disease(GD)in the China Han population from Xuzhou city, Jiangsu Province. Methods Total 1 066 GD patients and 1 107 control subjects were recruited for genotyping by Taqman probe technique on Fluidigm EP1 platform. Meanwhile, serum concentrations of thyroid hormone and TSH receptor antibodies(TRAb)were determined. Results The rs179247_A, rs12101261_T were significantly associated with GD risk(OR=1.35, 95%CI 1.19-1.54, P=5.92×10-6; OR=1.32, 95%CI 1.16-1.50, P=2.22×10-5). Logistic regression identified that rs179247 was an independent susceptibility locus of GD. Serum TRAb concentration showed a significant difference(P=0.015)among rs179247_AA, AG, and GG genotypes. Conclusion rs179247 and rs12101261 in TSHR intron 1 are both associated with GD, and rs179247 may contribute risk to GD independently. The polymorphism is associated with TRAb, but not with serum concentration of thyroid hormones, age of onset, diffused thyroid goiter, ophthalmic signs, and relapse.     

The c.273+11dup genetic change in the WAS gene is a functionally neutral polymorphism

Several pediatric patients showing symptoms consistent with the Wiskott-Aldrich syndrome (WAS) were referred to us and turned out to display the c.273+11dup change in the WAS gene. It consisted of the insertion of one C in an unusual tract of 7C near the intron 2 donor splicing site of the WAS gene. In the patients, non-synonymous WAS mutations were found twice only and one mutation was elucidated in RUNX1. In the absence of a non-synonymous mutation in the WAS gene, the c.273+11dup change affected neither the levels nor the sequence of WAS mRNA. In the presence of a non-synonymous WAS mutation, the c.273+11dup alteration failed to worsen the expected phenotype. Minor splicing abnormalities concerning exon 10 were observed both in WAS patients, and in healthy individuals carrying or not carrying the c.273+11dup. The c.273+11dup change was encountered four times in 107 normal male and female controls (172 alleles tested: 2.3%), and eight times in a series of 248 male patients (248 alleles tested: 3.2%). We conclude that the presence of the additional C in the WAS gene is a functionally neutral polymorphism.     

Carrier detection and prenatal diagnosis by intron 22 inversion analysis of the factor VIII gene

Summary In approximately 50% of severe haemophilia A patients the mutation is present in the form of a large chromosomal disruption in the factor VIII gene; this disruption is described as an inversion. It results in the physical breakage and separation of exons 1-2 and exons 23-26 of the factor VIII gene.