Angelman综合征的遗传学诊断

目的 探讨Angelman综合征(Angelman syndrome,AS)的遗传学诊断,为临床诊断和遗传咨询提供信息.方法 应用甲基化特异性PCR(methylation-specific PCR,MS-PCR)对16例临床疑似AS病例进行基因诊断,并选择15号染色体特定区域内、外的短串联重复序列作为遗传标记对MS-PCR诊断阳性的AS核心家系进行连锁分析,以进一步确定其分子病理学类型.结果 应用MS-PCR技术诊断10例AS患儿,家系连锁分析显示10例AS患儿中有9例为15q11-13片段缺失型,1例为印记缺陷型.结论 MS-PCR检测能够诊断大部分AS,家系连锁分析可进一步区分其具体的分子病理学类型.开展相关的遗传诊断对临床诊断、遗传咨询以及产前诊断都具有积极的作用.     

二例Angelman综合征临床及脑电图分析

<正>快乐木偶综合征,为常染色体隐性遗传性疾病。临床表现主要是发育迟缓、颅面部异常、共济失调、阵发性发笑、癫痫发作等。本病的遗传机制主要是15号染色体长臂11区到13区缺失(15q11-13 deletion)。国外研究表明,Angelman综合征具有较为特征性的临床及脑电图改变,其中EEG为诊断Angelman综合征的一项敏感方法,常能在临床症状明显前及基因诊断前提示本病,从而有助于早期     

应用分子生物学技术产前诊断Down综合征

目的 探讨应用PCR分子生物学方法产前诊断Down综合征（Down syndrome,DS)。方法 取产前诊断病例：羊水100例，绒毛16例。提取DNA，PCR扩增21号染色体的6个多态位点，电泳，膜转移，等位基因位点分析，诊断。结果 正常人为两种带型：杂合型显示两条带，纯合型一条带。Down综合征患者为三种带型：完全杂合型显示三条带，半杂合型两条带（信号增强的2：1带），纯合型一条带。100例羊水中2例阳性，16例绒毛标本中1例阳性，3例患者，至少有2个位点检出三个等 基因，患者为2个位点时，表现2：1带型；无一例正常检出三个等位基因。所有结果均与细胞染色体核型检查相符。结论 本分子生物学方法产前诊断DS简便、快速、可行，是一种值得推广的方法。     

Angelman综合征1例报道及康复训练情况

Angelman综合征(Angelman syndrome,AS)是一种神经遗传性疾病,主要表现为愉快面容,常伴有欣快感和爆发性大笑,运动发育迟缓、严重语言障碍、肌张力低下、癫痫等。本文作者对其所在康复中心收治的1例Angelman综合征的临床、辅助检测及康复训练情况作以汇报。     

一例先天性唇腭裂胎儿的产前诊断

目的分析1例先天性唇腭裂胎儿的遗传学病因。方法应用染色体微阵列分析技术(chromosomal microarray analysis,CMA)检测胎儿及其家系成员染色体拷贝数变异(copy number variation,CNVs)。结果CMA检测显示胎儿为男性,其染色体Xp11.22区域存在228 kb的DNA片段缺失,染色体9p21.1区域存在721 kb的DNA片段重复,两个CNVs均遗传自亲代。其中染色体Xp11.22区域的CNV为可疑致病性CNV,致病基因为PHF8,9p21.1区域的CNV为良性CNV。结论染色体Xp11.22区域DNA片段缺失可能为胎儿唇腭裂的原因。     

运用Array-basedCGH技术进行胎儿染色体异常综合征的诊断研究

目的运用高分辨率的Array-basedCGH（aCGH）技术研究染色体的微小变异（缺失或扩增）引起的胎儿畸形综合征,及其形成机理。方法采用Agilent4×44K CGH芯片对一个正常标本和三个畸形胎儿标本DNA（M1正常胎儿;M2腹壁缺损;M3单脐动脉合并先天性心脏病,右室双出口,室间隔缺损,肺动脉狭窄,二尖瓣闭锁;M4染色体核型47,＋21,先天性心脏病,室间隔缺损,胎儿一侧侧脑室增宽,胎儿偏小）进行比较基因组杂交检测。结果 M2/M1：高拷贝（扩增）560条DNA（基因）片断,低拷贝或缺失1504条DNA（基因）片断;M3/M1：高拷贝511条DNA（基因）片断,低拷贝或缺失1142条DNA（基因）片断;M4/M1：高拷贝3034条DNA（基因）片断,低拷贝或缺失3571条DNA（基因）片断。结论染色体片段的微小变异是引起胎儿畸形综合征的主要病因之一,高分辨率的aCGH技术可快速准确对其检测和产前诊断。     

产前诊断Phelan-McDermid综合征细胞分子遗传学研究

目的 报道一例罕见的Phelan-McDermid综合征胎儿的临床病例,探讨细胞分子遗传学检查在Phelan-McDermid综合征诊断中的应用价值.方法 对孕妇行羊膜腔穿刺获取胎儿细胞进行培养并行染色体核型分析来确定胎儿的染色体核型.结果 胎儿的羊水染色体核型分析结果为46,XX,del(22)(ql3),单核苷酸多...     

唐氏综合征产前诊断的研究进展

唐氏综合征（Down＇s syndrome,DS）又称21-三体综合征,是人类最常见的染色体疾病,目前均无有效的治疗方法。对唐氏综合征最有效办法是早发现和及时终止妊娠,也是实施优生优育的重要措施。本文介绍了DS的相关因素,就孕妇血清指标、超声软指标、尿样指标以及遗传学、分子学、无创性产前检测技术在唐氏综合征筛查、诊断方面的研究进展作一综述。     

22q11.2微缺失综合征胎儿的产前诊断及家系分析

目的:分析22q11.2微缺失综合征胎儿的产前诊断、亲代验证及妊娠结局,为遗传咨询提供依据。方法:对低深度全基因组测序技术(copy number variation sequencing,CNV-Seq)或染色体微阵列分析(chromosomal microarray analysis,CMA)发现的6例22q11....     

一个Angelman综合征家系的临床表型及遗传学分析

目的:明确1个Angelman综合征(Angelman syndrome,AS)家系的遗传学病因,为家系的遗传咨询提供理论依据。方法:应用高通量测序技术进行单基因遗传智力障碍相关基因检测;应用拷贝数变异测序技术(copy number variation sequencing,CNV-seq)进行染色体非整倍体、100...     

Angelman syndrome and prenatally diagnosed Prader-Willi syndrome in first cousins

Prader-Willi syndrome (PWS) and Angelman syndrome (AS) are caused by loss of function of imprinted genes in the 15q11-13 critical region. Reports of PWS and AS in close relatives within the same family are rare. We report on the diagnosis of a familial unbalanced 10;15 translocation causing AS in a child that led to the prenatal diagnosis of an unbalanced 10;15 translocation with resultant deletion of the Prader-Willi critical region in her maternal uncle's offspring.     

Prenatal diagnosis of chromosome 15 abnormalities in the Prader-Willi/Angelman syndrome region by traditional and molecular cytogenetics

With improvements in culturing and banding techniques, amniotic fluid studies now achieve a level of resolution at which the Prader-Willi syndrome (PWS) and Angelman syndrome (AS) region may be questioned. Chromosome 15 heteromorphisms, detected with Q- and R-banding and used in conjunction with PWS/AS region-specific probes, can confirm a chromosome deletion and establish origin to predict the clinical outcome. We report four de novo cases of an abnormal-appearing chromosome 15 in amniotic fluid samples referred for advanced maternal age or a history of a previous chromosomally abnormal child. The chromosomes were characterized using G-, Q-, and R-banding, as well as isotopic and fluorescent in situ hybridization of DNA probes specific for the proximal chromosome 15 long arm. In two cases, one chromosome 15 homolog showed a consistent deletion of the ONCORPWS/AS region A and B. In the other two cases, one of which involved an inversion with one breakpoint in the PWS/AS region, all of the proximal chromosome 15 long arm DNA probes used in the in situ hybridization were present on both homologs. Clinical follow-up was not available on these samples, as in all cases the parents chose to terminate the pregnancies. These cases demonstrate the ability to prenatally diagnose chromosome 15 abnormalities associated with PWS/AS. In addition, they highlight the need for a better understanding of this region for accurate prenatal diagnosis. © 1995 Wiley-Liss, Inc.     

Angelman syndrome in adulthood

We studied the clinical and EEG-findings in 28 adult patients (aged 20–53 years) with Angelman syndrome (AS). Twenty-three showed a maternal chromosome 15q11–13 deletion; in 5, the diagnosis was based on a combination of typical clinical findings. Compared to the clinical manifestations present in childhood, “coarsening” of facial traits (100%), thoracic scoliosis (71%), and being wheelchair-bound (39%) were found more frequently. Paroxysms of laughter were still observed in adulthood (79%), but less frequently than in childhood. Most adult patients could feed themselves, but needed help with many daily activities. The majority (82%) had epileptic seizures. Abnormal EEG-activity consisting of 2–3/s rhythmic triphasic waves of high amplitude with a maximum over the frontal regions, which has been identified in many AS children, was found in 67% of these adult patients. © 1996 Wiley-Liss, Inc.     

Clinical spectrum and molecular diagnosis of Angelman and Prader-Willi syndrome patients with an imprinting mutation

Recent studies have identified a new class of Prader-Willi syndrome (PWS) and Angelman syndrome (AS) patients who have biparental inheritance, but neither the typical deletion nor uniparental disomy (UPD) or translocation. However, these patients have uniparental DNA methylation throughout 15q11-q13, and thus appear to have a mutation in the imprinting process for this region. Here we describe detailed clinical findings of five AS imprinting mutation patients (three families) and two PWS imprinting mutation patients (one new family). All these patients have essentially the classical clinical phenotype for the respective syndrome, except that the incidence of microcephaly is lower in imprinting mutation AS patients than in deletion AS patients. Furthermore, imprinting mutation AS and PWS patients do not typically have hypopigmentation, which is commonly found in patients with the usual large deletion. Molecular diagnosis of these cases is initially achieved by DNA methylation analyses of the DN34/ZNF127, PW71 (D15S63), and SNRPN loci. The latter two probes have clear advantages in the simple molecular diagnostic analysis of PWS and AS patients with an imprinting mutation, as has been found for typical deletion or UPD PWS and AS cases. With the recent finding of inherited microdeletions in PWS and AS imprinting mutation families, our studies define a new class of these two syndromes. The clinical and molecular identification of these PWS and AS patients has important genetic counseling consequences. Am. J. Med. Genet. 68:195–206, 1997 © 1997 Wiley-Liss, Inc.     

唐氏综合征的无创产前诊断研究进展

唐氏综合征是最常见的染色体非整倍体遗传病,该病尚无有效治疗手段,出生干预是预防该病的有效措施。传统的产前筛查与产前诊断均具有一定的缺陷,无创产前诊断是未来发展的趋势。本文从母血胎儿细胞、母血胎儿游离DNA、母血胎儿游离RNA三个角度对目前唐氏综合征的无创产前诊断研究作一综述,以期对相关领域的研究发展有所帮助。     

FISH analysis in Prader-Willi and Angelman syndrome patients

We report on a combined high resolution cytogenetic and fluorescent in situ hybridization study (FISH) on 15 Prader-Willi syndrome (PWS) and 14 Angelman syndrome (AS) patients. High resolution banding showed a microdeletion in the 15q11-q13 region in 7 out of 15 PWS patients, and FISH analysis of the D15S11 and SNRPN cosmids demonstrated absence of the critical region in three additional cases. Likewise 8 out of 14 AS patients were found to be deleted with FISH, using the GABRB3 specific cosmid, whereas only 4 of them had a cytogenetically detectable deletion. © 1995 Wiley-Liss, Inc.     

Prader Willi/Angelman and DiGeorge/velocardiofacial syndrome deletions: Diagnosis by primed in situ labeling (PRINS)

A recently developed methodology—primed in situ labeling (PRINS)—can be used in place of fluorescence in situ hybridization (FISH) to diagnose microdeletions. To demonstrate the efficiency, sensitivity, and specificity of PRINS in the diagnosis of microdeletions, we studied groups of patients with Prader Willi/Angelman (PWS/AS) syndrome and DiGeorge/velocardiofacial syndrome (DGS/VCFS). Results obtained by PRINS were then confirmed with the results obtained with FISH. Oligonucleotide primers specific for SNRPN and GABRB3 were used for PWS/AS syndromes. For DGS/VCFS, the primers used were DGCR2/TUPLE1 loci. Labeling patterns obtained by PRINS and FISH were analyzed and scored under a fluorescence microscope. Five normal subjects served as controls and were used for standardization of the PRINS protocol. In all, 20 study patients were involved: 10 PWS/AS and 10 DGS/VCFS. Five of the 10 patients referred with the clinical diagnosis of PWS/AS showed absence of labeling for SNRPN and GABRB3 on one chromosome 15, confirming deletion of the two loci. Similarly, 6 of the 10 patients referred for DGS/VCFS showed deletion for the DGCR2/TUPLE1 loci on one chromosome 22. The remaining patients and controls had normal patterns for all the loci as indicated by FISH and PRINS. Concordant FISH and PRINS results were obtained in all patients and controls studied. © 2001 Wiley‐Liss, Inc.     

Unexpected familial recurrence in Angelman syndrome

We report on two instances of familial recurrence of Angelman syndrome which, from pedigree analysis, appear incompatible with currently known mechanisms of inheritance of this disorder. In these two families, deletion-positive Angelman syndrome has recurred in cousins. Several established mechanisms for deletion-positive familial recurrence have been ruled out. In each family, molecular cytogenetic studies show typical chromosome 15 deletions, and DNA methylation analysis verifies the maternal origin of the deleted chromosomes in all four individuals. Since the mothers of the affected individuals in each family are not known to be related, these recurrences appear to be secondary to coincidental, de novo events. This conclusion is consistent with direct and indirect estimates of the population frequency of Angelman syndrome. Am. J. Med. Genet. 70:253–260, 1997. © 1997 Wiley-Liss, Inc.