Hunter综合征患者IDS基因的一个新突变  

A new mutation of iduronate-2-sulfatase gene from the patient with Hunter syndrome

作　　者：郭奕斌[1] 林群娣[1] 杜传书[1] 

机构地区：[1]中山大学中山医学院医学遗传室,广州510080

出　　处：《中华医学遗传学杂志》2006年第1期67-69,共3页Chinese Journal of Medical Genetics

基　　金：美国中华医学基金会(CMB)部分基金资助项目(2003)~~

摘　　要：目的研究Hunter综合征患者的艾杜糖-2-硫酸酯酶(iduronate-2-sulfatase,IDS)基因的突变情况,为产前基因诊断等打下基础。方法应用尿粘多糖含量检测、聚合酶链反应-变性高效液相色谱(poly-merase chain reaction-denaturing high-performance liquid chromatography,PCR-DHPLC)分析对1例Hunter综合征患者及其父母的IDS基因的突变热点第9、3、8外显子进行突变检测,并对PCR-DHPLC检出的突变样品进行直接测序。结果经PCR-DHPLC分析发现该患者的IDS基因第9外显子有明显异常峰形;DNA序列分析进一步发现该外显子发生一新的移码突变,突变部位在第482位密码子(TTA)内,即cDNA第1569bp的T后插入了2个T,致使新肽链提前在第483位遇上终止密码TAA,导致新肽链从原来的550个氨基酸缩短至482个。该患儿为这一突变的半合子,而其母为这一突变的杂合子。结论PCR-DHPLC和DNA序列分析是诊断Hunter综合征的有效方法,发现的移码突变(1569+TT)导致肽链比正常的少了68个氨基酸,从而引起IDS酶活性明显降低,可能是该Hunter综合征患者的致病原因。Objective To identify the mutations of iduronate-2-sulfatase （ IDS ） gene, and to establish a basis of prenatal gene diagnosis of Hunter syndrome. Methods Urine glycosaminoglycan（GAG） assay was used to preliminary diagnosis of mucopolysaccharidosis. PCR-denaturing high-performance liquidchromatograptly（PCR-DHPLC） analysis was performed to detect the mutation in exons 9,3,8 of the IDS gene. DNA sequencing was applied to analyze the mutation detected by PCR-DHPLC. Results Abnormal peaks were found by PCR-DHPLC. A new frame-mutation （ 1569 ＋ TT ） in exon 9 of lIDS gene was identified by DNA sequencing. Two ＂T＂ inserted in pesition 1569 base pair（ 1569 ＋ TT） caused a substitution of codon 482（TTA, leucine） to 482（TTT, phenylalanine） . The ＂TT＂ insertion results in the decrease of amino acids from 550 to 482. The patient is a hemizygote and his mother is a heterozygote. Conclusion A new frame-shift mutation of IDS gene is found to report. The mutation （ 1569 ＋ TT） results in 68 amino acids lost. Probably it causes the enzyme activity seriously dropped down and being pathologically the basis of disease.

关 键 词：HUNTER综合征 粘多糖贮积症Ⅱ型 艾杜糖-2-硫酸酯酶 基因突变 变性高效液相 色谱 DNA序列分析 

分 类 号：R596.1[医药卫生—内科学] R596[医药卫生—临床医学]