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肝豆状核变性类似杂合丢失现象的报告及可能机制探讨 |
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马少春 倪星群 徐评议 梁秀龄
摘 要: 对39个家系45个病人及60例正常人的ATP7B基因的几个外显子采用8~10%的非变性丙稀酰胺胶进行SSCP分析, 并对异常者测序(放射自显影), 发现一个家系的8号外显子上同时存在两个突变(C2250G和G2273T),患者属纯合子,其父为杂合子,母亲和妹妹为正常, 类似“杂合丢失现象”。提示在除了肿瘤之外的体细胞遗传病中,二次突变理论也可能是突变发生的机制之一。 关键词: 杂合丢失;肝豆状核变性;基因突变 中图分类号: R742.4;Q754 文献标识码: A 文章编号: 0253-9772(1999)04-0011-14
Loss of Heterogrogyzosity in a Patient s Family with Wilson s Disease and Probable Mechanism
MA Shao-chun1, XU Ping-yi1, LIANG Xiu-ling1 1.Department of Neurology,First Affiliated Hospital,Sun Yat-Sen University of Medical Sciences;
NI Xing-qun2 2.Department of Forensic Biology,Sun Yat-Sen University of Medical Sciences,Guangzhou510080,China
Abstract: Screen for mutation in many exons with 45 Wilson disease patients in 39 Chinese families by SSCP and nucleotide sequence analysis by autoradiograph. There are two mutations in exon 8 of a patient s family: C2250G and G2273T. Found in these two mutation points, the patient s father is a heterozygote, patient s mother and sister are normal sequences, and patient is a homozygous. It just like a loss of heterogyzosity in this family with Wilson disease. The patient and her parent sibship were confirmed by taternity test with microsatellite vWF SE33 AR and D9S112. The result suggested that Loss of heterozygosity (LOH) is probable mutate mechanism of hereditary disease besides tumor and cancer. Key words: Loss of heterozygosity;Wilson s disease;Gene mutation
1971年, Kundson在系统研究了一种有时呈显性遗传的儿童肿瘤成视网膜细胞瘤(Retinoblastoma, RB)后,提出癌变的“二次突变理论”〔1〕,认为一个正常的成视网膜细胞变成癌细胞需经两次突变。如果第一次突变已存在于双亲之一配子中,则婴儿的所有体细胞中均已含有此突变,任何一个成视网膜细胞中发生第二次突变即可使之成为瘤细胞。此后多位学者在研究“杂合性丢失”现象时再次肯定了二次突变理论,该理论解释了多种癌变发生的机制〔4~7〕。作者在研究肝豆状核变性的基因突变时,在39个家系45例病人3个外显子的检测时,发现其中一例基因突变中,存在类似“杂合丢失”现象,现报道该病例并讨论发生突变的可能机制。
1 材料与方法 1.1 临床资料 肝豆状核变性(Wilson s disease, WD)患者经中山医科大学附属第一医院神经内科确诊,具有典型的症状和体征,角膜K-F[1] [2] 下一页 上一个医学论文: 中国成都地区汉族人群DHFRP2位点的遗传多态性研究 下一个医学论文: 一个与非小细胞肺癌转移相关的基因 RAB5A基因
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