臺灣博碩士論文加值系統

自閉症是一種異質性的神經發展障礙疾病，此疾病通常在三歲前即可被診斷出來。主要的臨床特徵為社交障礙、說話及語言能力不良和刻板且重複的興趣及行為。在過去的文獻顯示，自閉症有非常高的遺傳率，然而，是甚麼樣的基因會造成此疾病，目前所知甚少。我們之前利用Array Comparative Genomic Hybridization analysis (array CGH) 在一位患有自閉症的男孩中，發現在8 號染色體的短臂上有約2.4Mb 的缺失，而在這缺失的區域中包含了23 個基因。自閉症發生的原因之一和基因突變有關，因此我們在這2.4Mb 缺失的區域中，篩選和神經發育有關的基因，本篇研究所探討的基因為FBXO25 及ARHGEF10 這兩個基因。我們利用定序的方式，尋找FBXO25 及ARHGEF10 基因序列是否有發生基因突變，然後進行病例對照研究，我們的樣本包括360 位自閉症患者及400 位對照組，病例組及對照組均為台灣漢民族。我們於FBXO25 基因發現一個突變，為R38H，在對照組中亦有發現此突變。病例對照發生突變人數的比例分析結果發現，這兩組比較結果並沒有任何差異。在ARHGEF10 基因發現十一個基因突變，包括D96N, G118C, G187S、E189V、R275H、V700I、T970M、T1173S、I1241F、Y1282C、及R1320S，其中，在病例中發現五個突變G118C、G187S、E189V、T970M 及Y1282C，而這五個突變在對照組中均沒發現。由SIFT 及
PolyPhen 網站，均預測出ARHGEF10 基因中的G118C、R275H 及T1173S，這三種變異可能會造成蛋白質功能的損害，而ARHGEF10 基因的E189V，只有被SIFT 指出為有害的變異。另外，進行病例對照分析，只有ARHGEF10 基因的E189V 變異，從病例組及對照組的基因型頻率及對偶基因頻率比較分析結果為有顯著差異(基因型頻率，p=0.03；對偶基因頻率，p=0.04)。而這些變異或許是為增加罹患自閉症的風險之一。

Autism spectrum disorder (ASD) is a heterogeneous group of neurodevelopment disorders, it can be diagnosed before three years of age, the syndromes of ASD are defined by the damage of social interaction, abnormal development of speech and language, and highly restricted interests and stereotyped behavior. Previous studies showed that ASD are highly heritable, however, the disease causing genes are poorly known. We recently reported that using Array Comparative Genomic Hybridization analysis (array CGH), a boy with ASD who had a terminal deletion at the short arm of chromosome 8, was detected.The deletion
region contains 23 genes. To further elucidate which genes might be associated with ASD, we investigated two genes in this study, i.e. F-box protein 25 (FBXO25) and the Rho guanine nucleotide exchange factor 10 (ARHGEF10). To investigate whether the FBXO25 and the ARHGEF10 are associated with ASD, we set out to screen mutations of these two genes in ASD. We used PCR-based direct sequencing to screen mutations at all the exonic regions of these two genes in 360 ASD patients and 400 controls. We identified a missense
mutation R38H in the FBXO25 in one patient. In ARHGEF10 gene, we identified several missense mutations, including D96N, G118C, G187S, E189V, R275H, V700I, T970M, T1173S, I1241F, Y1282C, and R1320S. Five mutations, G118C, G187S, E189V, T970M and Y1282C, were only found in patients, but not in controls. Computer programs of PolyPhen and SIFT predict that G118C, R275H and T1173S mutations of ARHGEF10 gene are probably damaging. And only in SIFT, E189V was probably damaging. In ARHGEF10, E189V mutation had significant difference of genotype frequency and allele frequency of case-control analysis (genotype frequency, p=0.03, allele frequency, p=0.04). These mutations might be result in increased risk to ASD.

中文摘要....................................................III
英文摘要......................................................V
緒論..........................................................1
實驗目的.....................................................10
材料與方法...................................................11
結果.........................................................15
討論.........................................................21
參考文獻.....................................................24
附錄.........................................................27

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