本文關(guān)鍵詞： 鎖骨顱骨發(fā)育不全綜合征 RUNX2基因 基因突變 拷貝數(shù)改變　出處：《中南大學(xué)》2010年碩士論文　論文類型：學(xué)位論文

【摘要】： 背景：鎖骨顱骨發(fā)育不全(Cleidocranial Dysplasia,CCD)是一種罕見的遺傳性骨骼系統(tǒng)疾病(MIM 119600),出生發(fā)病率為1：100,000。該綜合征多為常染色體顯性遺傳方式,其致病基因定位于染色體6p21。以往研究表明成骨細(xì)胞特異性轉(zhuǎn)錄因子(RUNX2/CBFA1)的雜合突變、基因插入、缺失等是造成CCD的重要原因。此外,該病具有極強(qiáng)的外顯率和明顯的家族聚集性,且性別間無明顯差異。典型的CCD臨床表現(xiàn)包括：鎖骨發(fā)育不良或無鎖骨,囟門和顱縫增寬、延遲閉合或不閉合,身材矮小,出牙晚和恒牙數(shù)目增多等骨骼異常。這些骨骼異常所造成的身體畸形給患者帶來了沉重的生活壓力和心理負(fù)擔(dān)。 目的：通過對收集到的兩個鎖骨顱骨發(fā)育不全家系的RUNX2基因突變研究,進(jìn)一步探索該病的分子發(fā)病機(jī)制。 方法：對臨床收集到的兩個鎖骨顱骨發(fā)育不全綜合征家系行外周血基因組DNA的提取,利用聚合酶鏈?zhǔn)椒磻?yīng),DNA直接測序檢測突變。對檢測到的突變用DHPLC方法在健康人群中進(jìn)行篩查。對未發(fā)現(xiàn)RUNX2基因位點(diǎn)突變的患者行熒光原位雜交檢測及全基因組拷貝數(shù)檢測。 結(jié)果：家系一中每位CCD患者均存在RUNX2基因c.507delC的雜合突變,從而使171位氨基酸的密碼子CTG移碼變成TGA而提前終止,改變了RUNX2基因中runt功能域的氨基酸序列。家系二中患者DNA測序未發(fā)現(xiàn)RUNX2基因突變,后經(jīng)包含RUNX2基因的BAC探針熒光原位雜交以及全基因組拷貝數(shù)分析顯示該患者存在包含RUNX2基因在內(nèi)的3.5Mb大片段雜合缺失。 結(jié)論：本研究在家系一患者中檢測到的雜合點(diǎn)突變c.507delC造成RUNX2基因編碼氨基酸發(fā)生移碼改變而提前終止。在家系二患者中檢測到的3.5Mb大片段雜合缺失包含了整個RUNX2基因,使得RUNX2編碼蛋白質(zhì)的功能完全缺乏。這兩種基因組改變分別是引起兩家系中CCD患者患病的原因。這兩種突變類型是在鎖骨顱骨發(fā)育不全患者中首次被檢測到的RUNX2基因新突變。兩種新突變類型的確立進(jìn)一步擴(kuò)展了CCD的突變譜,將會對CCD產(chǎn)前診斷和植入前診斷產(chǎn)生積極的影響。
[Abstract]:Background: Cleidocranial Dysplasia (CCDD) is a rare hereditary skeletal system disease with a birth incidence of 1: 100000.This syndrome is mostly autosomal dominant. Previous studies have shown that heterozygosity, gene insertion and deletion of osteoblast specific transcription factor RUNX2 / CBFA1 are important causes of CCD. The typical clinical manifestations of CCD include hypoplasia of clavicle or no clavicle, widening of fontanelle and cranial suture, delayed closure or unclosure, short stature. The abnormal bones, such as late tooth emergence and increasing number of permanent teeth, bring heavy life pressure and psychological burden to the patients due to the body deformities caused by these abnormal bones. Objective: to investigate the molecular pathogenesis of RUNX2 gene mutation in two clavicular cranial dysplasia families. Methods: genomic DNA was extracted from peripheral blood of two families with clavicular cranial dysplasia syndrome. Polymerase chain reaction (PCR) was used to detect mutations by direct sequencing. The detected mutations were screened by DHPLC method in healthy population. Fluorescence in situ hybridization (Fish) and whole genome copy number (copy number) were performed in patients with no mutation of RUNX2 gene. Results: the heterozygosity mutation of RUNX2 gene c.507delC was found in every CCD patient in the first family, thus the 171-amino acid codon CTG frame shifter was transformed into TGA and terminated earlier. The amino acid sequence of runt functional domain in RUNX2 gene was changed. No mutation of RUNX2 gene was found in the DNA sequence of family 2 patients. Fluorescence in situ hybridization with BAC probe containing RUNX2 gene and whole genome copy number analysis showed that the patient had 3.5Mb heterozygosity deletion including RUNX2 gene. Conclusion: the heterozygous point mutation c.507delC detected in this study caused the change of coding amino acids of the RUNX2 gene and terminated early. The 3.5Mb heterozygosity detected in the patient of the second home line contained the entire RUNX2 gene. These two genomes changes are the cause of the disease of CCD patients in two families. These two mutation types are the first detected RUNX2 in patients with clavicular cranial dysplasia. The establishment of two new mutation types further expanded the mutation spectrum of CCD. It will have a positive impact on CCD prenatal diagnosis and pre-implantation diagnosis.
【學(xué)位授予單位】：中南大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2010
【分類號】：R681.1;R394

【參考文獻(xiàn)】

相關(guān)期刊論文 前4條

1 陳學(xué)武,華冰,李立峰,劉建勇,陶宗貴;顱鎖骨發(fā)育不全[J];泰山醫(yī)學(xué)院學(xué)報;2002年03期

2 張萬林,吳運(yùn)堂;顱骨-鎖骨發(fā)育不全綜合征在曲面體層片上的影像特點(diǎn)[J];現(xiàn)代口腔醫(yī)學(xué)雜志;2002年03期

3 邱正慶,唐愛蘭,余衛(wèi),敖楊,羅會元,魏珉,張學(xué);一例顱鎖骨發(fā)育不良患兒的RUNX2基因突變研究[J];中華兒科雜志;2004年10期

4 王瑩,吳華,張曉霞,趙紅珊,馮海蘭;家族性鎖骨顱骨發(fā)育不全的基因突變檢測[J];中華口腔醫(yī)學(xué)雜志;2005年06期

，

本文編號：1509516