21-羟化酶缺乏症患者CYP21基因点突变研究  

CYP21 gene point mutations study in 21-hydroxylase deficiency patients

作　　者：廖相云[1] 张雅芬[1] 顾学范[1] 

机构地区：[1]上海第二医科大学附属新华医院,上海市儿科医学研究所内分泌,遗传代谢病科,200092

出　　处：《中华儿科杂志》2003年第9期670-674,U003,共6页Chinese Journal of Pediatrics

基　　金：国家自然科学基金资助项目 ( 79870 778);上海市高教局基金资助项目 ( 0 1B0 4 )

摘　　要：目的　了解CYP2 1基因编码区的常见突变谱和突变热点 ,并分析基因型和表现型的关系。方法　对来自 51个家庭的 52例 2 1 羟化酶缺乏症患者的全长CYP2 1基因分两个片断进行特异性聚合酶链反应 (PCR)扩增 ,在此基础上进行相应的巢式PCR扩增 ,再根据突变的特点分别采用限制性片段长度多态性 (RFLP)和扩增产生酶切位点 (ACRS)的方法 ,检测 6种突变 :P3 0L、I2g(内含子 2的nt 656a/c→g剪切突变 )、E3Δ8nt(外显子 3第 111～ 113密码子的 8bp缺失 )、I172N、V2 81L和Q3 18X。结果　在 10 2个等位基因中 ,除了 2 7个等位基因外都能够确定基因型。最常见的突变为I2g ,其发生频率为 3 1% ,其次为I172N( 2 3 % ) ,Q3 18X( 14 % ) ,V2 81L( 9% ) ,P3 0L( 3 % ) ,E3Δ8nt( 2 % ) ,其中有 2个以上复合突变的等位基因占 6%。失盐型患者最常见的突变为I2g( 4 5 7% )和Q3 18X( 2 6% )。单纯型最常见的突变为I172N( 4 0 7% )和I2g( 18 5% )。结论　本组 52例患者中 73 %的等位基因突变为上述 6种突变 ,以I2g和I172N为突变热点 ,2种突变占 54%。Objective The major cause of congenital adrenal hyperplasia(CAH) is 21 hydroxylase deficiency, which accounts for 90%～95% of all cases in most populations This study was conducted to characterize the molecular basis of the 21 hydroxylase deficiency and to obtain the spectrum of the CYP21 gene mutations in a group of Chinese patients, and analyze the relationship of genotype and phenotype Methods To detect the distribution of gene mutations in Chinese population samples from 52 patients with 21 hydroxylase deficiency from 51 families were collected, including two parents samples in 30 patients and one parents sample in 10 patients Blood samples were obtained for extraction of peripheral blood lymphocytes Polymerase chain reaction (PCR) followed by nesed PCR were used to study the 21 hydroxylase gene (CYP21) mutations The primary PCR amplified two overlapping CYP21 specific DNA fragments, The product of the nested PCR which used products from the primary PCR was analysed by restriction fragment length polymorphism (RFLP) or amplification created restriction site (ACRS) All patients were studied by 6 mutations, including P30L, I2g (intron 2 nt 656 c/a→g splice mutation), E3Δ8nt (exon 3 codon111 codon113 8 bp deletion), I172N, V281L and Q318X Results Through analysis of 52 patients with 21 hydroxylase deficiency, in 5 patients no mutations were detected, in 17 patients only one mutated allele could be characterized, two different mutations were identified in 21 patients, three mutations were detected in 2 patients Totally, in 73% of alleles the genotypes could be detected The most common mutation was I2g,which present on 31% affected alleles, then followed by I172N, Q318X, V281L, P30L, E3Δ8nt, accounting for 23%,14%,9%, 3%,2% of all identified mutations respectively, which included multiple mutations accounting for 6% The most frequent molecular defects of the salt wasting form were the I2g (45 7%), Q318X (26%) Of the simple virilizing form, the dominant mutations were I17

关 键 词：21-羟化酶缺乏症 CYP21 基因点突变 先天性肾上腺皮质增生症 小儿 

分 类 号：R725.8[医药卫生—儿科]