一例肝豆状核变性家庭的ATP7B基因突变研究

发布时间：2018-05-30 17:08

本文选题：肝豆状核变性 + ATP7B基因　；参考：《青岛大学》2017年硕士论文

【摘要】：目的通过对一例肝豆状核变形家系的基因分析,验证该病的遗传方式。同时对近年来国内所报道的肝豆状核变性致病基因病例进行回顾性分析,研究其在基因型与表现型之间的关系。从而为该病在临床中引起重视,减少误诊漏诊率做出贡献,为寻找肝豆状核变性新的诊疗思路提供方向。方法首先通过人类基因组DNA提取,聚合酶链反应(PCR)和DNA测序等分子生物学技术检测ATP7B突变。在二代测序得出结果后,通过Sanger一代测序验证前者结果的准确性。对先证者及其父母进行生化、血常规等实验室以及影像学检查,比较ATP7B基因检测结果及其性别,年龄,临床类型,血清铜蓝蛋白和尿铜的分析,分析其基因型和临床表型。其次通过回顾性分析肝豆状核变性患者,分析中国人ATP7B基因型的热点突变以及高频突变的分布规律;根据病人的临床资料,如年龄、性别、发病类型以及患病的严重程度,分析该病基因型与表现型的关系,以期得到确定性结果。结果患儿母亲ATP7B基因第8号外显子发生了错义突变(c.2333GT),突变类型为R778L;患儿父亲ATP7B基因第11号外显子发生了错义突变(c.2621CT),突变类型为A874V。两位突变基因携带者将致病基因遗传给子代,致使先证者患病。一代测序结果得出相同的结果。实验室检查结果表明,先证者肝功能异常。通过对近5年的相关文献进行回顾性分析,我们总共得到255例患者。发现中国人的突变热点为R778L,突变率为38.04%。主要的突变类型为错义突变,突变率为92.97%。不同基因型之间,表现型并无明显差别。结论肝豆状核变性患者继承了作为致病基因携带者的父母的隐性基因从而患病,即使突变基因基因型多种多样,但其发病机制以及临床表现并无明显差别。先证者出现肝功能异常,可见该病首先累积肝脏。其父母的相关实验室检查较为正常,可见单纯携带致病基因并不会对造成相关蛋白表达的异常。影像学检查显示先证者各脏器大小正常,可见如果能在发病早期做到及时的确诊以及治疗,会有效干预病程进展,且经过后续治疗预后效果非常好。在回顾的255例患者当中,有251例检测出基因突变,仍有4例未能检测出突变,其原因可能是这4例患者的突变并非定位于外显子上,可能存在于内含子或外显子与内含子连接处。如果能够获得先证者完整家系的基因分析是最好不过,但在实际当中要完成十分困难。因此对于先证者父母的同胞来说,他们也可能是致病基因的携带者。因此对于潜在的携带者,进行基因检测就十分必要。特别是对于即将生育下一代的,检查自己是否是致病基因的携带者,就更加重要。同时对于已经生育患病儿童的父母,在生第二胎之前,对胎儿进行基因筛查,进行产前基因咨询,是十分必要的。
[Abstract]:Objective to verify the genetic pattern of the disease by genetic analysis of a family with hepatolenticular deformities. The relationship between genotypes and phenotypes of hepatolenticular degeneration genes reported in recent years was analyzed retrospectively. Thus, it can make a contribution to the clinical attention, reduce the rate of misdiagnosis and miss diagnosis, and provide the direction for finding a new diagnosis and treatment of hepatolenticular degeneration. Methods Human genomic DNA was extracted, polymerase chain reaction (PCR) and DNA sequencing were used to detect ATP7B mutation. After the second generation sequencing, the accuracy of the former result was verified by Sanger generation sequencing. Biochemistry, blood routine examination and imaging examination were performed on the proband and their parents. The results of ATP7B gene analysis, sex, age, clinical type, serum ceruloplasmin and urine copper were compared, and their genotypes and clinical phenotypes were analyzed. Secondly, by retrospective analysis of patients with hepatolenticular degeneration, the hot spot mutation and high frequency mutation of ATP7B genotypes in Chinese were analyzed, according to the clinical data of the patients, such as age, sex, type of disease and severity of the disease. The relationship between genotypes and phenotypes of the disease was analyzed in order to obtain deterministic results. Results the missense mutation in exon 8 of ATP7B gene was found in the mother and the mutation type was R778L, and the missense mutation in exon 11 of the father ATP7B gene was identified as A874V. Two carriers of mutated genes passed on the disease-causing genes to their offspring, causing the proband to become ill. A generation of sequencing results yielded the same results. The results of laboratory examination showed that the liver function of the proband was abnormal. A total of 255 patients were obtained by retrospective analysis of the literature in the last 5 years. It was found that the hot spot of mutation in Chinese was R778L, and the mutation rate was 38.04L. The main mutation type was missense mutation, the mutation rate was 92.97%. There was no significant difference in phenotype between genotypes. Conclusion the patients with hepatolenticular degeneration inherited the recessive genes of their parents as carriers of pathogenic genes, and had no significant difference in their pathogenesis and clinical manifestations, even though the mutation genotypes were varied. The liver function is abnormal in the proband, and the liver accumulates first. The relative laboratory tests of their parents showed that simply carrying pathogenic genes did not cause abnormal expression of related proteins. Imaging examination showed that the size of the organs of the proband was normal. It can be seen that if we can make timely diagnosis and treatment in the early stage of the disease, we can effectively intervene the progression of the disease course, and the prognosis is very good after the follow-up treatment. Of the 255 patients reviewed, 251 detected mutations and 4 failed to detect mutations, possibly because the mutations were not located in the exon. It may exist at the junction of intron or exon with intron. Genetic analysis of the proband's complete family is best, but is difficult to complete in practice. Therefore, for the proband's parents, they may also be carriers of the pathogenic gene. Therefore, for potential carriers, genetic testing is very necessary. Especially for those about to bear the next generation, it is even more important to check if you are carrying the disease-causing genes. At the same time, it is necessary for parents who have already given birth to sick children to carry out genetic screening and prenatal genetic counseling before giving birth to the second child.
【学位授予单位】：青岛大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R742.4

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