权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Molecular mechanism for inherited thyroxine-binding globulin excess and isolated growth hormone deficiency

遗传性甲状腺素结合球蛋白过多和孤立性生长激素缺乏的分子机制

基本信息

批准号：
09671082
负责人：
MORI Yuichi
金额：
$ 2.24万
依托单位：
Aichi Medical University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09671082/
关键词：
TBG isolated GH deficiency TBG excess gene amplification PCR FISH cosmid vector Chromosome walking TBG完全欠損症 TBG減少症

项目摘要

1. In this study, new 3 TBG excess families were analyzed, one familial and 2 sporadic cases. Amplification of the TBG gene was detected in 1 familial and 1 sporadic case by using duplex PCR-HPLC method but not in 1 sporadic case, in which a search for the molecular defect is in progress.2. The gene dosage of TBG was estimated in 8 families with inherited TBG excess (4 Japanese and 4 Caucasian families) and 3 sporadic Japanese family by using duplex PCR- HPLC method. Amplification of the TBG gene was detected in 10/11 families, 3 fold in 5 families and 2 fold in 3 inherited families and 2 sporadic cases. Serum TBG values were corresponded to TBG gene dosage. Then gene amplification was shown to be a main mechanism for inherited TBG excess. As 2 fold amplification was shown in both of 2 sporadic cases, the gene amplification was considered to increase from 2 to 3 fold by a unequal crossing over of the chromosome.3. Amplification of the TBG gene was also evaluated in 6 Japanese and one Caucasian families with FISH using chromosomes and a TBG probe. Although, 3 fold amplification, corresponding to the results of PCR-HPLC analysis, was demonstrated in 1 Japanese and 1 Caucasian family, other 5 families were shown to be indistinguishable from normal subjects. The size of the amplified unit might be smaller than the detection limit of FISH.4. In order to clarify the mechanism for the gene amplification, RFLPs were evaluated in 5 Japanese families using genomic DNAs and 12 restriction enzymes. Nevertheless, no RFLP was detected in all subjects, demonstrating that a breakpoint of amplified unit exist outside of 52 kbp covered by 12 enzymes. Cosmid libraries were constructed from genomic DNAs of a normal and a male TBG excess subject complicated with isolated GH deficiency. Then, DNA fragments of 75 kbp in the normal and 82 kbp in the affected subject were obtained by chromosome walking. No differences were so far detected between 2 subjects.

1.在这项研究中，分析了3个新的TBG过多的家庭，一个家庭和2个散发病例。结果：1.双重PCR-HPLC法在1例家族性和1例散发性病例中检测到TBG基因扩增，但在1例散发性病例中未检测到TBG基因扩增，其分子缺陷正在寻找中.应用双重PCR-HPLC法对8个遗传性TBG过多家系（4个日本人和4个高加索人家系）和3个日本散发家系的TBG基因剂量进行了测定。11个家族中有10个家族检测到TBG基因扩增，其中5个家族扩增3倍，3个遗传性家族和2个散发病例扩增2倍。血清TBG值与TBG基因的剂量相对应。基因扩增是遗传性TBG过多的主要机制。由于2例散发病例均显示2倍扩增，因此认为基因扩增由2倍增加到3倍是由于染色体的不等交换。扩增的TBG基因也进行了评估，在6个日本和一个高加索家庭与FISH使用染色体和TBG探针。尽管在1个日本人和1个高加索人家系中证实了与PCR-HPLC分析结果相对应的3倍扩增，但其他5个家系显示与正常受试者无法区分。扩增单位的大小可能小于FISH的检出限。为了阐明基因扩增的机制，使用基因组DNA和12种限制性内切酶对5个日本家庭的RFLPs进行了评价。然而，在所有受试者中均未检测到RFLP，表明在12种酶覆盖的52 kbp之外存在扩增单位的断点。从正常和男性TBG过量受试者的基因组DNA构建粘粒文库，该受试者伴有孤立的GH缺乏症。然后，通过染色体步移获得正常人75 kbp和患病受试者82 kbp的DNA片段。到目前为止，2例受试者之间未检测到差异。