圆锥动脉干畸形与染色体22q11.2微缺失之间的关系

染色体22q11.2微缺失综合征患儿中约80％合并有先天性心血管畸形.研究发现,染色体22q11.2区内基因(TBX1、CRKL、ERK2)参与染色体22q11.2微缺失的发生.合并染色体22q11.2微缺失最常见的心血管畸形是圆锥动脉干畸形,包括法洛四联症、室间隔缺损型肺动脉闭锁、永存动脉干以及主动脉弓中断.主要表型...     

TBX1启动子区核苷酸变异与心脏圆锥动脉干畸形相关性研究

目的验证TBX1启动子区核苷酸变异与心脏圆锥动脉干畸形的相关性。方法招募621例心脏圆锥动脉干畸形患儿,采用MLPA方法检测患儿22q11.2区基因组DNA的拷贝数,排除22q11.2微缺失患儿。对605例无22q11.2微缺失的心脏圆锥动脉干畸形患儿和588例正常对照儿童,采用PCR扩增和基因测序方法,进行TBX1启动子区序列分析(-2000..+1),并应用生物信息学软件对变异位点进行功能预测分析。结果心脏圆锥动脉干畸形患儿中发现存在TBX1基因启动子区位点变异,其中包括3个已报道的单核苷酸多态性(SNP)和7个罕见变异位点,突变的发生率约为1.7%。应用Ali Baba 2.1对7个罕见变异位点进行分析,显示其中3个位点可能影响相关反式作用因子与TBX1启动子区顺式作用元件的结合。结论 TBX1启动子区核苷酸变异可能与心脏圆锥动脉干畸形发生相关。     

单纯性圆锥动脉干畸形22q11.2微缺失发生率及临床表型研究

目的 探讨单纯性圆锥动脉干畸形(CTD)染色体22q11.2微缺失发生率及临床表型分析.方法 应用多重连接探针扩增法(MLPA)对77例0～10岁单纯性CTD患儿进行染色体22q11.2微缺失筛查,并对阳性样本进行荧光原位杂交(FISH)验证.采用Fisher精度检验,P＜0.05有统计学意义.结果 用MLPA对77例单纯性CTD患儿进行了22号染色体微缺失筛查,其中55例法乐四联症(TOF),4例肺动脉闭锁伴室间隔缺损(PA-VSD),8例右室双出口(DORV),10例大动脉转位(TGA).6例(7.8%)患儿存在染色体22q 11.2微缺失,其中4例为TOF,1例为PA-VSD,1例为DORV;10例TGA患儿中均未发现22q11.2缺失.结论 单纯性CTD染色体22q 11.2微缺失发生率约为7.8%.单纯性CTD患儿中,PA-VSD,DORV及TOF比TGA更易发生染色体22q11.2微缺失.应加强对单纯性CTD患儿的遗传筛查及咨询.     

筛查染色体22q11.2缺失综合征在先天性心血管畸形中的意义

染色体22q11.2缺失综合征(22q111DS)又称DiGeorge综合征、腭-心-面综合征,临床表现极具多样性,可累及心血管、免疫系统、面容、内分泌系统,甚至语言发育、精神等多方面.荧光原位杂交能够检测到染色体22q11.2缺失.目前国内对本病认识尚不足,尚未建立规范的临床筛查体系,确诊率亦低.已报道的22q11DS病例中,先天性心血管畸形尤其是圆锥干畸形和主动脉弓畸形发生率很高,也最确切.该文拟综述22q11DS,并分析如何在临床工作中从心血管畸形入手早期发现22q11DS,从而早期干预治疗、综合评估、长期随访及遗传咨询,提高患者及后代生活质量.     

染色体22q11.2微缺失综合征与TBX1基因

染色体22q11.2微缺失综合征主要由人类第22号染色体长臂近端微片段22q11·2缺失引起,其心脏畸形主要累及主动脉弓和心脏流出道。近年来在无微缺失的该综合征患者中发现有TBX1突变发生。在动物实验中也发现,Tbx1参与胚胎早期咽弓动脉的形成和神经嵴的正常迁移过程,并在心脏流出道的生长、连接和分隔形成等过程中有重要作用。TBX1在22q11.2微缺失综合征的发病机制中可能具有重要作用。     

4 046例染色体检查结果与先天性心脏病关系的回顾性分析

目的探讨染色体异常与先天性心脏病（先心病）的关系。方法回顾性分析复旦大学附属儿科医院1990年1月至2006年12月所进行染色体检查 的患儿中染色体异常的核型种类,并统计先心病患儿染色体的核型特点。结果共检测4 046例患儿的染色体,染色体异常660例（16.3%）,其中 常染色体异常以唐氏综合征最常见（458例,69.4％）;性染色体异常以特纳综合征最常见（105例,15.9%）。接受染色体检查的患儿中先心病 391例,其中染色体异常者185/391例（47.3%）,157/185例核型表现为唐氏综合征, 4/185例核型表现为特纳综合征。先心病中圆锥动脉干畸 形105例,其染色体核型异常发生率较低,仅为16/105例（15.2％）（P<0.05）。染色体核型正常的先心病患儿中,圆锥动脉干畸形和非圆锥动 脉干畸形分别有95和111例。结论染色体核型异常与先心病之间存在密切的相互联系。染色体核型异常易合并先心病;某些先心病患儿的染色体 核型异常发生率明显升高。但圆锥动脉干畸形与常见染色体异常间无密切联系。因此,对于染色体异常患儿应常规进行心脏检查,以及早发现 先心病。另外,尽管某些先心病患儿的普通染色体核型检查未发现异常,但有必要寻找更合适的检测技术提高染色体异常的检出率。     

22q11.2微缺失综合征的分子诊断及缺失范围检测

目的 分别采用多重连接探针扩增技术(MLPA)与荧光原位杂交技术(FISH)对22q1 1.2微缺失综合征外周血标本患者基因缺失/重复突变的类型及变异范围进行检测,分析在22q11.2微缺失综合征诊断中二者联合应用的诊断价值.方法 采集1例仅心脏异常患儿及其父母外周血,取200 μL外周血提取DNA后采用MLPA技术对患儿及其父母的染色体22q11.2缺失的范围进行检测,取外周血1 mL进行培养,采用DiGeorge/VCFS N25(D22S75)的FISH探针对培养后的中期淋巴细胞进行杂交.结果 患儿淋巴细胞分裂中期细胞应用FISH技术检测结果为22号染色体上的DiGeorge/VCFS N25(D22S75)区杂合性缺失;MLPA验证结果显示患儿与22q11.2微缺失综合征相关的6个探针对应的片段大小位置在3100的电泳图上荧光峰值相比健康对照明显出现减半,其父母亲均在正常范围.患儿的临床表现仅有先天性心脏病,无其他异常,与其基因缺失片段长度(2.0 Mb)极不相称.结论 联合应用FISH和MLPA检测22q11.2微缺失综合征,可以明显提高诊断的准确性.22q11.2微缺失综合征的临床表现与基因缺失片段的长度无相关性.     

自行设计的多重链接探针扩增组合对多发畸形患儿的诊断价值

目的 尝试基于多重链接探针扩增（MLPA）技术设计的探针组合对多发畸形(MCA)患儿的诊断价值。方法 以临床发现≥2个的畸形表型患儿为病例,基于MLPA技术选择13种常见的MCA的关键基因和关键区域自行设计MLPA探针组合（SIGMA公司合成）,以微阵列比较基因组杂交（aCGH）作为金标准,检验该探针组合的诊断准确性,再以MLPA探针组合行MCA临床诊断效果评估,对MLPA探针组合阳性的病例结合临床资料进行分析。结果 ①MLPA探针组合涉及的13种常见MCA,包括：21-三体综合征（KCNJ6、DYRK1A、RCAN1基因）、18-三体综合征（MC2R、DTNA、TCF4基因）、13-三体综合征（EDNRB、CENPJ、ERCC5、FREM2基因）、1p36区域缺失综合征（GABRD、SKI、TP73基因）、 5q35.3区域缺失综合征（Sotos综合征,NSD1基因）、CHARGE综合征（CHD7基因）、7q11.23区域缺失综合征（Williams Beuren综合征,CLIP2、ELN、LIMK1基因）;22q11.21区域缺失、重复综合征（DiGeorge综合征,SNAP29、TBX1、ZNF74基因）、17p11区域缺失综合征（Smith-Magenis综合征,RAI1、MFAP4基因）、5p15.2区域缺失综合征（Cri du Chat综合征, CTNND2、TERT基因）、15q11-13区域缺失综合征（Prader-Willi综合征,OCA2、UBE3A、GABRB3基因）、4p16.3区域缺失综合征（Wolf Hirschhorn综合征,MSX1、WHSC1、LETM1基因）、17q21.31区域缺失综合征（MAP3K14、MAPT基因）。②35例MCA中,aCGH检测阳性11例（31.4%）,共诊断9种;MLPA探针组合检测阳性6例（17.1%）,共诊断4种;MLPA组合探针检测阳性的6例微缺失和重复与11例aCGH检测阳性一致,6例MLPA探针组合检测阳性的变异位点均位于设计的MLPA探针组合中,122例临床MCA中,MLPA探针组合检测阳性21例（17.2%）,诊断6种。③在157例MCA患儿中,应用MLPA探针组合共诊断阳性病例27例,共检出7种（53.8%）,分别为21-三体综合征8例,18-三体综合征1例,5p15区域缺失综合征3例,22q11区域重复综合征1例、缺失综合征9例,5q35区域缺失综合征1例,15q11-q13区域缺失综合征3例,7q11.23区域微缺失综合征1例。结论 自行设计合成的MLPA探针组合对非典型临床表型的MCA病例有较好的诊断价值。     

HIRA基因在先天性心脏病发病机制中的作用

圆锥动脉干畸形是引起婴幼儿早期死亡的主要心血管畸形之一.研究表明,圆锥动脉干畸形与22号染色体长臂的微缺失有密切关系,其中,位于该染色体相关区域的HIRA基因被推测可能是与这一类型先天性心脏病发病具有重要关系的候选基因.     

染色体22q11．2微缺失综合征与TBX1基因

染色体22q11．2微缺失综合征主要由人类第22号染色体长臂近端微片段22q11．2缺失引起，其心脏畸形主要累及主动脉弓和心脏流出道。近年来在无微缺失的该综合征患者中发现有TBX1突变发生。在动物实验中也发现，Tbx1参与胚胎早期咽弓动脉的形成和神经嵴的正常迁移过程，并在心脏流出道的生长、连接和分隔形成等过程中有重要作用。TBX1在22q11．2微缺失综合征的发病机制中可能具有重要作用。     

Chromosome 22q11.2 microdeletion in children with conotruncal heart defects: frequency,associated cardiovascular anomalies,and outcome following cardiac surgery

The association of conotruncal heart defects with 22q11.2 chromosomal microdeletions is well established. However, it is not clear whether particular types of conotruncal malformations or additional cardiovascular anomalies are associated with microdeletions. In addition, cardiac surgery outcome in children with conotruncal defects and del22q11.2 is not well described. We prospectively enrolled 214 children with conotruncal defects: 126 with tetralogy of Fallot (TOF), 18 with pulmonary atresia-ventricular septal defect (PA-VSD), 15 with truncus arteriosus communis (TAC) type I, one with interrupted aortic arch (IAA) type B, and 54 with the transposition of great arteries, who were consecutively hospitalized at the Pediatric Cardiology Department between 2003 and 2005. 22q11.2 microdeletion was identified by fluorescence in situ hybridization. The postoperative course following cardiac surgery was compared in patients with TOF and its more severe form, PA-VSD, with/without del22q11.2 (groups A and B) and TAC with/without del22q11.2 (groups C and D). In 15 of 214 patients, 22q11.2 microdeletion was diagnosed (in 11 with TOF/PA-VSD, in three with TAC, in one with IAA type B). In patients with TOF/PA-VSD and microdeletion anatomic features that were significantly associated with 22q11.2, deletion included right aortic arch (p = 0.018), aberrant right subclavian artery (p < 0.001), and major aortopulmonary collateral arteries (p = 0.016). A complicated postoperative course was more frequent and mortality was higher in patients with conotruncal defects and with/without microdeletion. We conclude that additional cardiovascular anomalies are significantly more frequent in children with 22q11.2 microdeletion and TOF/PA-VSD. Children with conotruncal heart defects and 22q11.2 microdeletion more frequently experienced complicated postoperative course after cardiac surgery.     

Frequency of 22q11.2 microdeletion in children with congenital heart defects in western poland

Background

The 22q11.2 microdeletion syndrome (22q11.2 deletion syndrome -22q11.2DS) refers to congenital abnormalities, including primarily heart defects and facial dysmorphy, thymic hypoplasia, cleft palate and hypocalcaemia. Microdeletion within chromosomal region 22q11.2 constitutes the molecular basis of this syndrome. The 22q11.2 microdeletion syndrome occurs in 1/4000 births. The aim of this study was to determine the frequency of 22q11.2 microdeletion in 87 children suffering from a congenital heart defect (conotruncal or non-conotruncal) coexisting with at least one additional 22q11.2DS feature and to carry out 22q11.2 microdeletion testing of the deleted children's parents. We also attempted to identify the most frequent heart defects in both groups and phenotypic traits of patients with microdeletion to determine selection criteria for at risk patients.

Methods

The analysis of microdeletions was conducted using fluorescence in situ hybridization (FISH) on metaphase chromosomes and interphase nuclei isolated from venous peripheral blood cultures. A molecular probe (Tuple) specific to the HIRA (TUPLE1, DGCR1) region at 22q11 was used for the hybridisation.

Results

Microdeletions of 22q11.2 region were detected in 13 children with a congenital heart defect (14.94% of the examined group). Microdeletion of 22q11.2 occurred in 20% and 11.54% of the conotruncal and non-conotruncal groups respectively. Tetralogy of Fallot was the most frequent heart defect in the first group of children with 22q11.2 microdeletion, while ventricular septal defect and atrial septal defect/ventricular septal defect were most frequent in the second group. The microdeletion was also detected in one of the parents of the deleted child (6.25%) without congenital heart defect, but with slight dysmorphism. In the remaining children, 22q11.2 microdeletion originated de novo.

Conclusions

Patients with 22q11.2DS exhibit wide spectrum of phenotypic characteristics, ranging from discreet to quite strong. The deletion was inherited by one child. Our study suggests that screening for 22q11.2 microdeletion should be performed in children with conotruncal and non-conotruncal heart defects and with at least one typical feature of 22q11.2DS as well as in the deleted children's parents.     

Growth hormone deficiency in patients with 22q11.2 deletion: expanding the phenotype

The list of findings associated with the 22q11.2 deletion is quite long and varies from patient to patient. The hallmark features include: conoruncal cardiac anomalies, palatal defects, thymic aplasia or hypoplasia, T cell abnormalities, mild facial dysmorphia, and learning disabilities. The 22q11.2 deletion has been seen in association with the DiGeorge sequence, velocardiofacial syndrome (VCFS), conotruncal anomaly face syndrome, isolated conotruncal cardiac anomalies, and some cases of autosomal dominant Optiz G/BBB syndrome. Short stature has been seen in one to two thirds of children reported in the literature with a diagnosis of VCFS, but growth hormone deficiency (GHD) has not been described in conjunction with this diagnosis. We present 4 patients with a 22q11.2 deletion and short stature who were found to have abnormalities in the growth hormone-insulin-like growth factor I axis. All had growth factors less than -2 SD for age and failed provocative growth hormone testing. Two patients were found to have abnormal pituitary anatomy. In our population, the incidence of GHD in 4 or 95 children with 22q11 deletion is significantly greater than the estimated incidence of GHD in the general population. Children with a 22q11.2 deletion appear to be at a greater risk for pituitary abnormalities. Therefore, those children with the 22q11.2 deletion and short stature or poor growth should be evaluated for GHD, as replacement growth hormone therapy may improve their growth velocity and final height prediction.     

FISH investigation of 22q11.2 deletion in patients with immunodeficiency and/or cardiac abnormalities

DiGeorge anomaly/velocardiofacial syndrome (DG/VCFS), called 22q11.2 deletion syndrome in general, is the most common chromosomal deletion syndrome found in humans. Typical facial features, palatal defects, conotruncal abnormalities of the heart, aplasia/hypoplasia of the parathyroid glands and of thymus are characteristics of this syndrome. Deletions of chromosome 22q11.2 (del22q11.2) are the leading causes of DG7VCFS. We report on a systematic search by fluorescence in situ hybridization (FISH) for deletions of chromosomes 22q11.2 in patients with a clinical suspicion or diagnosis of DG/VCFS. Using FISH we studied a series of 43 patients with suspected DG/VCFS. In this study, a total of 43 patients were investigated for the presence of a 22q11.2 deletion over a two-year period. Del22q11.2 was detected in 5 of the 43 patients tested. All patients with deletion had hypocalcemia, 80% had cardiac defects, 40% had facial dysmorphism, 40% had immunodeficiency , and 20% had otolaryngeal abnormalities. Chromosome 22q11.2 deletion is a relatively common condition and is readily diagnosed by FISH. We suggest that FISH analysis of 22q11.2 deletion should be performed in the presence of combined of hypocalcemia and congenital cardiac malformations, with or without any characteristics of the disease. This may facilitate an early diagnosis in such patients.     

22q11.2 Deletions in Patients with Conotruncal Defects: Data from 1,610 Consecutive Cases

The 22q11.2 deletion syndrome is characterized by multiple congenital anomalies including conotruncal cardiac defects. Identifying the patient with a 22q11.2 deletion (22q11del) can be challenging because many extracardiac features become apparent later in life. We sought to better define the cardiac phenotype associated with a 22q11del to help direct genetic testing. 1,610 patients with conotruncal defects were sequentially tested for a 22q11del. The counts and frequencies of primary lesions and cardiac features were tabulated for those with and those without a 22q11del. Logistic regression models investigated cardiac features that predicted deletion status in tetralogy of Fallot (TOF). Deletion frequency varied by primary anatomic phenotype. Regardless of the cardiac diagnosis, a concurrent aortic arch anomaly (AAA) was strongly associated with deletion status [odds ratio (OR), 5.07; 95 % confidence interval (CI), 3.66–7.04]. In the TOF subset, the strongest predictor of deletion status was an AAA (OR, 3.14; 95 % CI 1.87–5.27; p < 0.001), followed by pulmonary valve atresia (OR, 2.03; 95 % CI 1.02–4.02; p = 0.04). Among those with double-outlet right ventricle and transposition of the great arteries, only those with an AAA had a 22q11del. However, 5 % of the patients with an isolated conoventricular ventricular septal defect and normal aortic arch anatomy had a 22q11del, whereas no one with an interrupted aortic arch type A had a 22q11del. A subset of patients with conotruncal defects are at risk for a 22q11del. A concurrent AAA increases the risk regardless of the intracardiac anatomy. These findings help to direct genetic screening for the 22q11.2 deletion syndrome in the cardiac patient.     

Growth hormone deficiency associated with 22q11.2 deletion: a case report

The 22q11.2 microdeletion produces many syndromes, characterized by similar phenotypical features. The most known syndromes are: the DiGeorge syndrome, the velocardiofacial syndrome, the conotruncal anomaly face syndrome. The hallmark features are represented by cardiac anomalies, palate defects, immune and cognitive deficiencies, facial dysmorphisms. Less common disorders include: genito-urinary abnormalities, visual defects, autoimmune disorders and pituitary anomalies, being the last represented by growth hormone and/or insulin growth factor-I deficiency. We present the case of a 8 years old male admitted to our Division for failure to thrive. We found growth hormone deficiency and pituitary hypoplasia associated with some of the anomalies shown above, thus we suspected and confirmed the 22q11.2 deletion syndrome. In literature few cases of associated 22q11.2 deletion syndrome with growth hormone deficiency are described, while short stature between children with and children without cleft palate is reported to be more frequent in the first ones, suggesting that the 22q11.2 deletion syndrome remains undetected in many affected children and that the growth hormone deficiency prevalence in affected children has to be investigated. The wide phenotypical presentation of 22q11.2 deletion syndrome requires a multidisciplinary approach to the affected subject and, from the auxologic point of view, is good to monitoring the growing trend and, if short stature is present, check for the growth hormone deficiency.     

22q11.2 deletion syndrome: DiGeorge, velocardiofacial, and conotruncal anomaly face syndromes.

A microdeletion of chromosome 22q11.2 is found in most patients with velocardiofacial syndrome, DiGeorge syndrome, and conotruncal anomaly face syndrome, and in some patients with Cayler cardiofacial and autosomal dominant Opitz-G/BBB syndromes. A wide spectrum of clinical findings accompanies the 22q11.2 deletion, without genotype or phenotype correlation even among affected family members. Classic features are dysmorphic facies, conotruncal cardiac defects, hypocalcemic hypoparathyroidism, T-cell mediated immune deficiency, and palate abnormalities. Less well recognized are learning, speech, feeding, and psychiatric disorders, and renal and musculoskeletal defects. Parathyroid and immune deficiencies in the same individual can progress or resolve with time. The 22q11.2 deletion can be inherited as an autosomal dominant or arise as a de novo deletion or translocation. Fluorescent in situ hybridization using cosmid probes mapping to the DiGeorge chromosomal region is a widely available method to detect the 22q11.2 deletion in metaphase chromosomes from cultured lymphocytes, amniocytes, or chorionic villi. The ubiquitin-fusion-degradation-1-like gene, expressed in embryonic branchial arches and in the conotruncus, appears to play a prominent role in the pathogenesis of the 22q11.2 deletion syndrome.     

A search for chromosome 22q11.2 deletions in a series of 176 consecutively catheterized patients with congenital heart disease: no evidence for deletions in non-syndromic patients

Microdeletions in chromosome 22q11.2 are associated with DiGeorge syndrome (DGS), velo-cardio-facial syndrome (VCFS), and several other syndromes, collectively referred to as DG/VCF. Non-dysmorphic patients with cardiac defects have also been attributed to deletions in this chromosomal region. In this study 157 consecutively catheterized patients with isolated, non-syndromic cardiac defects, and 25 patients with cardiac defects and additional stigmata (10 of whom were clinically diagnosed as DG/VCF cases prior to chromosome analysis) were analysed by fluorescence in situ hybridization with the DGS-specific probe D0832. Chromosome 22q11.2 deletions were observed only in the ten patients with the clinical diagnosis of DG/VCF. Conclusion In a large unselected cohort of patients with congenital heart disease no association between isolated or non-syndromic heart defects and the 22q11.2 microdeletion was observed. One can conclude that testing for the 22q11.2 microdeletion is clearly indicated in cases when even mild extracardiac abnormalities are present, particularly in very young infants. Received: 24 February 1998 / Accepted in revised form: 04 May 1999     

Molecular analysis of syndromic congenital heart disease using short tandem repeat markers and semiquantitative polymerase chain reaction method

BACKGROUND: Velo-cardiofacial syndrome (VCFS) and DiGeorge syndrome (DGS) are developmental disorders characterized by craniofacial anomalies and conotruncal heart defects. Many of them have hemizygous deletions within chromosome 22q11.2, suggesting that haploinsufficiency in this region are responsible for their etiologies. METHODS: To effectively understand the molecular basis for the chromosomal deletions, a semiquantitative fluores-cent polymerase chain reaction (PCR) method using 11 highly polymorphic markers located in 22q11.2 to perform genotyping analysis on 10 probands (five VCFS and five DGS) and their unaffected relatives were designed. RESULTS: Two VCFS and four DGS patients have a 3-Mb deletion; the other DGS patient has a 1.5-Mb deletion and a cross-over occurs in the same interval at the other allele. CONCLUSION: This results supports that the specific regions in 22q11.2 are susceptible to rearrangement and the deletions might be the genetic etiology of these syndromes. Most important of all, the new method, semiquantitative fluorescent PCR, is an effective method for detecting chromosomal microdeletions and has the following features: (i) the cost is inexpensive; (ii) the testing time is short; and (iii) the result is accurate.