应用PCR快速筛查脆性X综合征患儿

目的应用PCR快速筛查脆性X综合征患儿。方法采用PCR和聚丙烯酰胺凝胶电泳技术,对24例不明原因智力低下患儿的脆性X基因（CGG）n重复序列进行检测。结果在24例不明原因智力低下患儿中,筛查出1例脆性X综合征患者。结沦采用PCR技术扩增脆性X基因的（CGG）n重复序列,可对脆性X综合征患者进行快速筛查。     

应用PCR对脆性X综合征进行产前筛查与诊断

目的对脆性X综合征进行产前基因筛查与诊断。方法采用聚合酶链式反应（polymerase chain reaction,PCR）和聚丙烯酰胺凝胶电泳技术,对46例孕妇及其胎儿的脆性X基因（CGG）n重复序列进行检测,同时采用PCR扩增牙幼基因对胎儿性别进行鉴定。结果在46例孕妇及其胎儿中,检出2例前突变携带者孕妇,2例男性患者胎儿。结论采用PCR扩增脆性X基因（CGG）n重复序列,结合扩增牙幼基因进行性别鉴定,可对脆性X综合征进行产前筛查与诊断。     

脆性X综合征的筛查及基因诊断

目的：建立一种简便快速初步筛查脆性X综合征智力缺陷基因FMR－1突变的方法。方法：采用套式PCR技术对新生儿及婴幼儿的足跟血X染色体上基因FMR－1CGG重复序列进行扩增,通过以其拷贝数的鉴定筛查其突变型。结果：共筛查5200全新生儿和婴幼儿,查出1例男婴患者,其母亲是携带者。结论：套式PCR能简便快速地初筛出人群中携带者和可疑患者,对脆性X综合征的早期诊断和产前诊断有应用价值。     

河北省1012例智力低下脆性X综合征筛查及检测技术的研究

脆性X综合征(fragile X syndrome)是常见的智力低下遗传病,本征发病率在1/1000-1/2000[1].国外报道,发病率在男性约为1/2000,在智力低下中仅次于Down综合征,严重影响人口素质.     

中国女性对于FMR1突变产前筛查的态度调查

目的调查中国女性对于脆性X综合征产前筛查的态度。方法随机调查284位没有智力发育障碍及脆性X综合征家族史的女性,分为已婚已育（67/284）、已婚未育（54/284）及未婚未育（163/284）三组。结果各组愿意接受产前筛查的比率分别为77.6%、66.7%及74.9%。而各组选择在得知产前筛查结果阳性时愿意终止妊娠的比率分别为95.5%、92.6%及90.2%。结论在中国女性群体中对FMR1基因突变进行产前筛查有较高的接受度。大多数人选择接受针对脆X综合征的产前筛查。     

脆性X综合征的概况

脆性X综合征(fragile X syndrome,Fra(X)S)是X连锁不完全显性遗传病,该病由X染色体上的FMR-1基因改变引起FMRP表达异常造成.本文就脆性X综合征的遗传特征,FMR-1基因的致病机理,FMRP的功能,脆性X综合征的临床筛查与诊断等的国内外最新报道作一综述.     

应用Pfu DNA聚合酶进行脆性X综合征的筛查和产前基因诊断

脆性Ｘ综合征(fragile X syndrome)是一种最常见、发病率最高的X-连锁智力低下综合征，智商一般在50以下。群体发病率为男性1／1250，女性1/2500，女性携带者发生率为１/350－1／700，在遗传性智力低下中发病率仅次于先愚型[1]。     

甲基化特异性三重PCR检测FMR1基因突变的研究

目的探讨甲基化特异性三重PCR检测FMR1基因不同突变类型的价值。方法用甲基化特异性三重PCR方法检测了99例病人的FMR1基因,并用半巢式PCR和Southern印迹杂交方法进行比较。结果用甲基化特异性三重PCR检测出70例男性正常基因型、27例女性正常基因型,1例男性全突变基因型,1例女性前突变基因型,与半巢式PCR和Southern印迹杂交方法的检测结果相符。结论甲基化特异性三重PCR能准确检测FMR1突变的不同类型,适用于对脆性X综合征的临床筛查和诊断。     

脆性X综合征3个家系的基因诊断

采用快速毛细管ＰＣＲ非同位素检测及Ｓｏｕｔｈｅｒｎ印迹杂交技术，对３个脆性综合征家系１８名成员进行了基因型鉴定，其检出全突变患者４例，前突变女性携者４例及正常男性传递者２例，结果显示直接基因诊断方法较细胞遗传学检查更灵敏，对３个家系进行系谱分析证实其遗传特点符合Ｓｈｅｒｍａｎ推论与Ｓｍｉｔｈｓ的观察，同时提供了一种更加快速筛查脆性Ｘ综合征的非同位素ＰＣＲ诊断方法。     

Frequency of the fragile X syndrome in infantile autism

In a Swedish multicenter study, 102 cases of infantile autism (I.A.) were examined for fragile X (q27). The fragile X syndrome was observed in 13 of the 83 (16%) boys with I.A., but in none of the 19 girls with I.A.     

非同位素PCR及Southern印迹杂交分析检测脆性X综合征FMR-1基因突变

目的建立一种非同位素的检测脆性X综合征智力缺陷基因(FMR-1)突变的方法.方法采用PCR技术结合Southern 印迹杂交技术对FMR-1基因进行分析,进而确定其突变类型.结果共对190例样本进行了检测,其中2例为女性前突变携带者,1例为女性全突变患者.结论非同位素PCR方法可以简便、安全、可靠地检测FMR-1基因中(CGG)n 重复拷贝数,可作为临床上对脆性X综合征的筛查的首选方法;而非同位素Southern印迹杂交可对结果不确定者进一步进行检测.     

不明原因智力低下儿童脆性X综合征的筛查和基因诊断

目的建立一种快速分析脆性X综合征智力低下基因1(Fragile X mental retardation gene 1,FMR-1)突变的方法,对不明原因智力低下儿童进行脆性X综合征的筛查和诊断。方法应用7-deza-dGTP的PCR法一次性扩增FMR-1基因的(CGG)n的重复区,检测CGGn的重复序列的大小判断FMR-1基因状态(正常、突变前、突变后),对脆性X综合征可疑患儿快速筛查。结果在101例不明原因的先天性智力低下惠儿中,我们发现脆性X综合征患儿13例(男性10例,女性3例)。结论采用7-deza-dGTP扩增GC富集区的PCR法可对高危患儿进行快速筛查,确定携带者和患者。     

Folic acid therapy in the fragile X syndrome

Two brothers with fra(X) positive X-linked mental retardation (XLMR) were treated with folic acid. Initially a double blind cross-over design was employed followed by a long-term high dose trial. A decrease in the frequency of fra(X) positive cells was observed when low folic acid culture medium was used but not when an FUdR induction system was employed. Selected behavioral characteristics improved in both while receiving folic acid. Decreased hyperactivity, greater attention span, increased motor coordination, increased quantity and quality of speech were noted. Improvement in Leiter mental age and regression after cessation of treatment was seen in one subject but not in the other. Further controlled trials with larger numbers of subjects using high doses of folic acid over longer periods of time are needed to assess the possible benefits of this experimental form of treatment.     

Applicability of a checklist for clinical screening of the fragile X syndrome

In a population of 340000 in Southern Häme, Finland, there were 541 intellectually disabled adult males (> 16 years) known to the District Organisation for the Care of the Mentally Retarded in August 1993. Of these, 197 already had a confirmed etiological diagnosis, with 20 having the fragile X syndrome. The other 344 males were screened for the fragile X syndrome using a three-step method: a clinical checklist used by a specialist nurse, a clinical examination by a physician who was very familiar with the fragile X syndrome, and the FRAXA-locus gene test. Six new fragile X males were found. The minimum prevalence of the fragile X syndrome in the district was calculated to be 1:4400.     

Maternal attitudes to newborn screening for fragile X syndrome

Although fragile X syndrome (FXS) is the commonest cause of inherited intellectual disability the mean age of diagnosis in Australia is 5.5 years. Newborn screening for FXS can provide an early diagnosis, preventing the “diagnostic odyssey”, allowing access to early interventions, and providing reproductive information for parents. Parents of affected children support newborn screening, but few clinical studies have evaluated community attitudes. A pilot study in 2009–2010 was performed in a tertiary hospital to explore feasibility and maternal attitudes. FXS testing of male and female newborns was offered to mothers in addition to routine newborn screening. Mothers were provided with information about FXS, inheritance pattern, carrier status, and associated adult‐onset disorders. One thousand nine hundred seventy‐one of 2,094 mothers (94%) consented to testing of 2,000 newborns. 86% completed the attitudinal survey and 10% provided written comments. Almost all parents (99%) elected to be informed of both premutation and full mutation status and there was little concern about identification of carrier status or associated adult‐onset disorders. Most mothers (96%) were comfortable being approached in the postnatal period and supported testing because no extra blood test was required. Mothers considered an early diagnosis beneficial to help prepare for a child with additional needs (93%) and for reproductive planning (64%). Some were anxious about the potential test results (10%) and others felt their feelings towards their newborn may change if diagnosed with FXS (16%). High participation rates and maternal attitudes indicate a high level of maternal acceptance and voluntary support for newborn screening for FXS. © 2013 Wiley Periodicals, Inc.