经典型21-羟化酶缺乏症患者的基因型及临床表型研究

发布时间：2018-03-06 16:10

本文选题：21-羟化酶缺乏症　切入点：CYP21A2　出处：《重庆医科大学》2016年硕士论文　论文类型：学位论文

【摘要】：目的分析经典型21-羟化酶缺乏症基因型与临床表型之间的关系,了解其基因突变频率。对象与方法收集2011年10月至2016年1月期间就诊于重庆医科大学附属儿童医院临床诊断为经典型21-OHD并行21-羟化酶基因检测的患者共132例,大部分来自西南地区。21-羟化酶基因检测仅使用PCR-ACRS联合限制切割方法和Sanger测序法,与PubMed标准序列对比,CAH版本:NC-000006.11,GI:2224589818。将基因诊断阳性者按基因突变严重程度分组:重度突变组,包括携带重度突变的纯合突变及其之间的复杂杂合突变的患儿;中度突变组,包括携带I173N纯合突变及I173N与重度突变的复杂杂合突变的患儿;轻度突变组,包括为携带轻度突变的纯合突变及含有轻度突变的复杂杂合突变的患儿。结果在132例患儿中检测到存在异常基因突变者共117例,仅为无意义基因突变者8例,未检测出基因突变者7例。除无意义基因突变外共检测到36种基因突变,其中可以从既往文献中查询到的已知致病突变基因共16种,突变频率为80.3%(212/264),既往无报道的未知突变基因共20种,是否影响21-羟化酶活性情况不详,突变频率仅为11.7%(31/264)。基因诊断阳性率仅为65.2%。重度突变组中,54例为失盐型患儿,7例为单纯男性化患儿;中度突变组中,1例为失盐型患儿,20为单纯男性化患儿;轻度突变组中4例全部为单纯男性化患儿。重度突变组的中位数初诊年龄(0.1岁)显著低于中度突变组(3.6岁)和轻度突变(3.15岁),中度突变组与轻度突变中位数组初诊年龄无显著差异;重度突变组中失盐表现的患儿比例(88.5%)显著高于其他两组(5%,0)。最常见的基因突变为I2g(37.9%)及I173N(13.6%),其次为Q319X(6.4%),R357W(5.7%)。失盐型患儿中检出率最高的为I2g(47.6%);在单纯男性化患儿中检出率最高的2种突变为I173N(34.7%)及I2g(21.4%)。结论按基因突变严重程度的分组方法,基因型能有效预测失盐型诊断及单纯男性化型诊断,其阳性预测值分别为,失盐型88.5%,单纯男性化型95.2%,能帮助临床分型及指导治疗,提供遗传咨询。本研究132例经典型21-OHD最常见的基因突变为I2g(37.9%)及I173N(13.6%),其次为Q319X(6.4%),R357W(5.7%),与我国上海地区点突变基因分布频率相似,而与北京、新疆、台湾地区有所不同。本研究仅使用PCR-ACRS联合限制切割方法和sanger测序法,且仅报告碱基点突变及其导致的氨基酸改变,诊断阳性率低,对临床指导意义有局限。联合多重连接依赖式探针扩增技术(MLPA)检测基因的大片段缺失情况,并进一步验证新发突变的对21-羟化酶活性的影响程度,能提高基因诊断阳性率,提高临床参考价值。
[Abstract]:Objective to analyze the relationship between the classical 21- hydroxylase deficiency and clinical phenotype with genotype, understand the gene mutation frequency. During the period from October 2011 to January 2016, the object and the method of treatment in clinical diagnosis of children's Hospital Affiliated to Medical University Of Chongqing for the classic 21-OHD parallel detection of 21- hydroxylase gene in patients with a total of 132 cases, mostly from the detection of.21- hydroxylase gene in Southwest China only use the PCR-ACRS joint limit cutting method and Sanger sequencing method, compared with PubMed standard sequence, CAH version: NC-000006.11, GI:2224589818. gene positive diagnosis by gene mutation severity groups: severe mutation group, including carrying homozygous mutation and severe mutations between children with heterozygous mutations; moderate mutation group, including carrying I173N homozygous mutation and heterozygous mutations in children with I173N complicated with severe mutation; mild mutation group, including for articles With a mild mutation homozygous mutation and contains mild mutation complex heterozygous mutation in children. The results detected the presence of abnormal gene mutations in 132 cases among the 117 cases, only 8 cases of meaningless mutations were not detected, 7 cases of gene mutation. The significance of gene mutation were detected 36 kinds of gene mutation, which can query from previous known pathogenic mutations were in the literature 16, the mutation rate was 80.3% (212/264), no previous reports of the unknown mutations were 20, whether the effect of 21- hydroxylase activity is unknown, the mutation frequency was only 11.7% (31/264) gene. The positive rate of diagnosis was only severe 65.2%. mutation group, 54 cases for the loss of salt type children, 7 cases of male patients with moderate; mutation group, 1 cases for the loss of salt type children, 20 were simple male children; mild mutation in 4 cases. All patients with simple virilizing mutation group in. Median age (0.1 years old) was significantly lower than the moderate mutation group (3.6 years old) and mild mutation (3.15 years old), moderate and mild mutations in mutation group had no significant difference in age at diagnosis in children with severe mutations in the array; the proportion of loss of performance in the salt group (88.5%) was significantly higher than that of the other two groups (5%, 0). Common gene mutations of I2g (37.9%) and I173N (13.6%), followed by Q319X (6.4%), R357W (5.7%). Salt losing type with the highest detection rate was I2g (47.6%); the highest detection rate of 2 for the I173N mutation in the pure male children (34.7%) and I2g (21.4%). Conclusion according to the severity of the mutation grouping method, genotype can effectively predict the loss and simple diagnosis of male salt type diagnosis, the positive predictive value was 88.5%, salt losing type, simple virilizing 95.2%, can help the clinical classification and treatment, to provide genetic counseling. In this study, the gene mutation 132 cases of classic 21-OHD For I2g (37.9%) and I173N (13.6%), followed by Q319X (6.4%), R357W (5.7%), similar to the point of China's Shanghai region gene mutation frequency distribution, with Beijing, Xinjiang, Taiwan area is different. This study uses only PCR-ACRS joint limit cutting method and Sanger sequencing method, and only report of base mutation and lead to amino acid changes, the positive diagnosis rate is low, there is a limitation to the clinical significance. Combined with multiplex ligation dependent probe amplification (MLPA) deletion detection, and further validation of new mutations of 21- hydroxylase activity influence, can improve the gene diagnosis positive rate, improve the clinical reference value.

【学位授予单位】：重庆医科大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：R725.8

【相似文献】