發(fā)布時間：2018-06-09 17:07

  本文選題：先天性甲狀腺功能低下(CH) + 雙氧化物酶2(DUOX2)��； 參考：《西北大學(xué)》2017年碩士論文

【摘要】：先天性甲狀腺功能減低癥(congenital hypothyroidism,CH)是一種常見的由于甲狀腺發(fā)育不全或者甲狀腺內(nèi)分泌機能障礙而引起的內(nèi)分泌疾病。研究發(fā)現(xiàn)由于甲狀腺激素分泌不足導(dǎo)致的CH多數(shù)是遺傳因素導(dǎo)致的,雙氧化物酶2(DUOX2)基因作為甲狀腺激素合成的關(guān)鍵基因,其突變對CH的形成有著重要的影響。本研究共招募到西北地區(qū)135例CH患者和100例健康個體,采用高通量測序的方法對患者DUOX2全外顯子和外顯子內(nèi)含子剪接處進行測序,同時對篩選出來的候選致病位點進行一代測序驗證,并在100例健康樣本對照中進行頻率驗證。然后利用計算生物學(xué)的方法對這些潛在致病位點的功能和效應(yīng)進行分析,同時分析DUOX2突變譜和CH臨床表型的關(guān)系,并且根據(jù)美國醫(yī)學(xué)遺傳學(xué)與基因組學(xué)學(xué)會和美國分子病理學(xué)會(ACMG/AMP)序列變異注釋標準對其進行致病等級的劃分。結(jié)果發(fā)現(xiàn):在135例CH患者中共檢測到49個罕見突變和2個功能多態(tài)性位點。在49個罕見突變中,有35個是錯義突變,6個插入缺失突變,6個無義突變和2個剪接突變,其中11個是首次發(fā)現(xiàn)的新突變,它們在健康對照中的頻率均小于1%。在135例患者中DUOX2突變檢出率為60.7%(82/135),并且有4個熱點突變(p.R1110Q,p.S1067L,p.R885Q,p.K530X)在CH患者和健康對照組中存在顯著差異。采用SIFT,PolyPhen-2,MutationTaster,FATHMM,M-CAP等5個蛋白質(zhì)功能預(yù)測軟件對所有錯義和無義突變的分析發(fā)現(xiàn)21個突變可能會損害蛋白質(zhì)的功能;利用MaxEntScan,NetGene2和BDGP 3個軟件對剪接突變分析發(fā)現(xiàn)2個突變(IVS28+1GT,IVS17+IGT)都可能會損害蛋白質(zhì)的功能。研究發(fā)現(xiàn)患者所攜帶DUOX2的突變類型和位點數(shù)與臨床表型沒有直接的關(guān)系,其基因型和臨床表型之間存在非常復(fù)雜的關(guān)系。對新發(fā)現(xiàn)的疑似致病位點進行7個物種間序列保守性分析,結(jié)果發(fā)現(xiàn)4個(p.D137E,p.R434_S440del,p.F591S,p.M1093V)位于保守區(qū),可能對蛋白質(zhì)結(jié)構(gòu)和功能產(chǎn)生影響。最后綜合目前已知的所有證據(jù),根據(jù)ACMG/AMP對疑似致病位點的致病等級的劃分標準,發(fā)現(xiàn) 7 個突變位點(p.R1110Q,p.R885Q,IVS28+1GT,p.R842X,IVS17+1GT,p.K530X,p.Q481X)為致病的(pathogenic)、9 個可能致病的(likeyly pathogenic)、33 個意義不明的(variants of unknown significance)以及 2 個(p.S1067L,p.H678R)良性突變位點(benign)。另外,本研究發(fā)現(xiàn)的兩個功能多態(tài)性位點中,p.S1067L與CH的發(fā)生風(fēng)險增高有關(guān)(OR=2.2,P=0)�？傊�,本研究首次采用高通量測序技術(shù)對西北地區(qū)CH患者的DUOX2基因突變進行篩查研究,分析了西北地區(qū)甲低患者中DUOX2突變的類型、特點、以及與臨床表型的關(guān)系,這對于擴大DUOX2基因突變譜,進一步了解CH致病機制具有重要的理論價值。
[Abstract]:Congenital hypothyroidism is a common endocrine disease caused by hypothyroidism or hypothyroidism. It is found that most of the Ch secreted by thyroid hormone is caused by genetic factors. As the key gene of thyroid hormone synthesis, the mutation of the dioxase 2DUOX2 gene has an important effect on the formation of Ch. In this study, 135 Ch patients and 100 healthy individuals were recruited in Northwest China. High throughput sequencing was used to sequence the splicing sites of the full exon and intron of DUOX2 in patients. At the same time, the candidate pathogenicity sites were sequenced for one generation and the frequencies were verified in 100 healthy controls. Then the function and effect of these potential pathogenic sites were analyzed by computational biology, and the relationship between the DUOX2 mutation spectrum and the clinical phenotype of Ch was also analyzed. According to the American Society of Medical Genetics and Genomics and the American Society of Molecular Pathology (ACMG / AMP) sequence variation annotation standard, the disease grade was classified. The results showed that 49 rare mutations and 2 functional polymorphic loci were detected in 135 patients with Ch. Of the 49 rare mutations, 35 were missense mutations, 6 insertion deletion mutations, 6 nonsense mutations and 2 splicing mutations, of which 11 were new mutations found for the first time, and their frequencies were less than 1 in healthy controls. In 135 patients, the detection rate of DUOX2 mutation was 60.7 / 82 / 135, and there were significant differences between Ch patients and healthy controls. Five protein function prediction softwares such as SIFTX PolyPhen-2 Mutation Tasterboard FATHMMMM-CAP were used to analyze all missense and nonsense mutations. It was found that 21 mutations might damage the function of protein. Using MaxEntScann NetGene2 and BDGP to analyze splicing mutations, it was found that two mutants, IVS281GTG / IVS17 IGT, might damage the function of protein. It was found that the mutation type and site number of DUOX2 were not directly related to the clinical phenotype, but there was a very complex relationship between the genotype and the clinical phenotype. The conserved sequences of 7 new suspected pathogenicity loci were analyzed. The results showed that the conserved region was 4 p. D137EN. R434E p. R440dellp. F591Sn. M1093V), which might have an effect on the structure and function of proteins. Finally, synthesizing all known evidence, according to ACMG / AMP's criteria for the classification of suspected pathogenicity sites, It was found that 7 mutation loci, p. R1110QN, p. R885QnIVS28, GTP. R842XnIVS17, GTP.K530X, p. Q481X) were 9 pathogenetic of unknown significance) of pathogenicity, 33 variants of unknown significance) with unknown significance, and 2 benign mutation loci of p. S1067LPH678R. In addition, two functional polymorphic loci were found in this study. S1067L was associated with increased risk of Ch. In conclusion, the DUOX2 gene mutations in Ch patients in Northwest China were screened by high-throughput sequencing for the first time. The types, characteristics and clinical phenotypes of DUOX2 mutations in patients with hypothyroidism were analyzed. It has important theoretical value for expanding the mutation spectrum of DUOX2 gene and further understanding the pathogenesis of Ch.
【學(xué)位授予單位】：西北大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：R581.2

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相關(guān)期刊論文 前1條

1 許宇翔;吳毓敏;;新生兒先天性甲狀腺功能低下篩查分析及治療隨訪[J];航空航天醫(yī)藥;2010年01期

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本文編號：2000487