Detection of a new mutation (1467-A) for the pedigree withmucopolysaccharidosis type Ⅱ from a Chinese family

Mucopolysaccharidosis type II (MPS II) is a disabling, fatal monogenic disease caused by abnormal metabolism of the mucopolysaccharides[1]. Gene mutation is the basic cause of MPS II and investigation of the IDS gene muta-tion is the premise for prenatal gene diagnosis and gene therapy. MPS II is worldwide distributed with high inci-dence and serious results. To study the IDS gene of Chi-nese MPS II patients is important not only in carrying out one-family policy but also in upraisi…     

A pointmutation of PRL gene in pituitary prolactin-secreting adenoma induced by 17-b-estradiol inSD rats

Animal model bearing pituitary prolactin-secreting adenomas (prolactinoma) induced by 17-β-estradiol (E₂) in both eutopic pituitary and ectopic pituitary grafted under the renal capsule was generated. Northern blotting assay indicated that PRL mRNA level in eutopic prolactinomas was higher than that in normal pituitaries and ectopic prolactinomas (P < 0.05-0.01). By polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP) analysis and DNA sequencing, a point mutation from C to A occurring at -36 nt in proximal promoter of rat PRL (rPRL) gene was found only in eutopic prolactinomas. No base change was detected in ectopic prolactinomas. Fusion gene transfection assayin vitro exhibited increased activity of the mutant promoter derived from eutopic prolactinoma (P < 0.01). These data suggested that the base change in the proximal promoter of rPRL gene may be associated with hyperexpression of rPRL gene in eutopic prolactinomas. The pathogenesis of eutopic and ectopic prolactinomas induced by E₂ in SD rats may be separate.     

导致人视网膜色素变性的RPGR基因突变

用ＰＣＲ－ＳＳＣＰ和ＤＮＡ测序的方法在两个ＸＬＲＰ家系ＲＰＧＲ基因的１２号和９号外显子内各发现一个未报道的突变。这两个突变引起了严重的视网膜色素变性。     

耐热碱性磷酸酯酶基因的DNA序列分析

从栖热菌中克隆到产耐热碱性磷酸酯酶（FD－TAP）基因并进行了DNA序列分析,结果表明此2．0kb的片段含有一个1056bp的开放阅读框,编码501个氨基酸的蛋白质,其N端有一26个氨基酸的信号肽．在起始密码子的上游5bp处有一个5＇－GGAGGT－3＇的SD序列．基因编码区的（G＋C）％为68．7％,第3位密码子（G＋C）％为92．7％．FD－TAP的氨基酸序列与大肠杆菌等生物的碱性磷酸酯酶氨基酸序列比较,相同性为27％,相似性为38％．中央β－折叠区及与活性中心相关的氨基酸残基高度保守．表明FD－TAP具有与大肠杆菌碱性磷酸酯酶相似的结构和作用机制．在相当于大肠杆菌碱性磷酸酯酶的His370至His412两个金属离子结合部位之间,FD－TAP有一72个氨基酸的插入片段,提示该插入片段与FD－TAP的高耐热性相关．     

眼皮肤白化病患者的TYR基因突变类型初步研究

目的:对临床诊断为眼皮肤白化病(OCA)患者的TYR基因进行突变筛查,以了解我国大陆OCA患者TYR基因突变类型。方法:应用PCR技术扩增患者及其父母的TYR基因外显子、外显子-内含子交界区及启动子区,以DNA序列测定技术进行突变筛查与鉴定。结果:在8名患者的16个TYR等位基因内,查明9种突变;其中错义突变4种(R77Q、E294K、R299H和W 400L),无义突变2种(R116X和R278X),插入突变2种(929 insC和232 insGGG),剪切位点突变1种(IVS1-3 C>G)。结论:W 400L、R299H分别占本研究所检出全部OCA1突变等位基因的31.3%(5/16)和18.8%(3/16),可能为中国大陆人群中较常见的TYR基因突变类型。     

以病毒的230 kb DNA分子为模板的DNA序列测定

目的：为确认Tn3-gpt已插入小鼠巨细胞病毒(mouse cytomegalovirus,MCMV)基因组的特定位置,改进大分子病毒DNA的测序方法,建立以230kb DNA为模板直接进行DNA序列测定的方法。方法：待测MCMV的Tr3-gpt插入突变株感染NIH3T3细胞后,从培养液中制备病毒颗粒并从中纯化得到基因组DNA,以此DNA为模板,合成的寡核苷酸为引物,用热循环方法按Promega公司的DNA Cycle Sequencing System试剂盒的方法进行测序。结果：获得纯度较高可直接作为模板进行测序的：DNA,测序所得放射自显影图片条带清晰明亮,间隔正常,分辨率较高,可顺利读出插入位点的MCMV的DNA序列,证实Tn3-gpt插入在特定的位置。结论：长达230kb的大分子病毒DNA可直接作为模板,用热循环测序方法进行测序,无需切割成小片段后才进行测序。     

Mutations analysis of STK_(11) gene in Chinese families with Peutz-Jeghers syndrome

Peutz-Jeghers syndrome (PJS) is an autosomal dominant disease that is characterized by multiple gastrointestinal hamartomatous polyps and melanin spots on lips and buccal mucosa at young age[1,2]. Previous studies have demonstrated that PJS predisposes carriers to cancers of gastrointestinal tract, uterus, ovary, testis, breast and other extragastrointestinal organs[3—5]. The STK11 gene, encoding a serine/threonine kinase at chro-mosome 19p13.3, was identified in 1998 as the main causativ…