先天性心脏病患儿22q11微缺失的定量荧光聚合酶链反应检测

目的 建立对22q11染色体微缺失进行快速批量检测的技术,用于非综合征先天性心脏病患 者染色体微缺失情况的检测.方法 采用定量荧光聚合酶链反应(quantitative fluorescent polymerase chain reaction,QF-PCR)法和8个短串联重复(short tandem repeat,STR)多态标记对79例中国汉族非综合征先天性心脏病(congenital heart defects,CHD)患者和84名正常对照者进行染色体22q11微缺失的检测.结果 缺失区域的STR标记在受检的非综合征型先天性心脏病患者中的平均杂合率为0.76,在正常对照人群中为0.79.在受检的1例法洛氏四联症患儿中检测到22q11微缺失(1.3%),经多重连接依赖探针扩增(multiplex ligation-dependent probe amplification,MLPA)技术验证结果正确.结论 采用QF-PCR法,可以高效批量地对22q11染色体微缺失进行筛查.     

胎儿先天性心脏畸形产前遗传学研究

目的 评估胎儿先天性心脏病(congenital heart diseases,CHD)遗传学异常情况,为孕期管理和遗传咨询提供依据.方法 对产前超声检查发现为先天性心脏畸形的胎儿共81例,采用绒毛活检/羊膜腔穿刺/脐静脉穿刺获取胎儿细胞,进行细胞培养染色体分析;对显带分析无染色体异常胎儿,采用短串联重复标记结合多重荧光定量PCR技术,检测其22q11.2区域微缺失和微重复情况,异常胎儿再用荧光原位杂交技术证实.结果 81例先天性心脏畸形胎儿,发现染色体异常34例,22q11.2微重复1例,总异常发现率为43.2%;合并心外畸形胎儿染色体异常率高于单纯心脏畸形胎儿(64.5%vs.28.0%).染色体异常中,18三体有19例,占染色体异常病例的54.3%.结论 先天性心脏畸形的胎儿染色体异常率高,尤以18三体最为常见;如合并心外畸形,染色体异常概率明显增加;对显带分析染色体正常胎儿则需进行22q11.2区域微缺失和微重复检测.先天性心脏畸形胎儿的遗传学检测有助于孕期管理和遗传咨询.     

荧光原位杂交在产前诊断胎儿先心病22q11微缺失中的应用

目的应用荧光原位杂交（FISH）技术检测胎儿染色体22q11微缺失,以探讨该技术在胎儿先天性心脏病病因检测中的临床应用。方法对41例产前诊断有各类心脏畸形、且染色体核型分析结果未见明显异常的胎儿以及1例先证者进行FISH检测,检测探针位于22q11微缺失综合征微缺失关键区域22q11的TUPLE1基因,与22q末端ARSA基因。结果 41例胎儿FISH检测均成功,所有胎儿22q11两位点均未发现微缺失;一胎儿家庭的1名先证者经检测确证为22q11微缺失综合征患者。结论胎儿心脏畸形有多种病因,常规染色体检查仅能检出其中一部分染色体数目异常,对于各种微缺失综合征,仍然需要FISH、芯片等更高分辨率的技术手段应用,对相关可能的致病位点进行针对性检测或筛检,以提高病因检出率,防止心脏畸形患儿出生。     

应用PCR技术检测先心病患者中22q11微缺失

目的为了建立一种在先天性心脏病（congenital heart disease,CHD）患者中快速、有效检测染色体22q11微缺失检测方法。方法从22q11区域内选取5个短串联重复多态位点（STRs）（D22S941、D22S944、D22S264、D22S311、D22S306）,应用PCR扩增方法对20例CHD患者及其父母进行22q11微缺失筛查。结果发现4例CHD患者可能存在22q11微缺失。对筛查出可疑阳性病例再运用荧光标记PCR—STR分型方法进行诊断,结果有1例确诊为D22s941缺失。结论此项研究表明普通PCR方法只能作为22q11微缺失筛查的一种手段,荧光标记PCR—STR分型由于准确、高效,可以作为22qll微缺失确诊方法。     

慢粒患者经格列卫治疗后细胞遗传学改变:标准Ph易位t(9;22)(q34;q11)变为变异Ph易位t(21;22)(p11;q11)

目的通过对慢性粒细胞白血病(chronic myeloid leukemia,CML)患者经格列卫药物治疗后细胞遗传学改变的研究,探讨ABL-BCR的表达缺失与获得性格列卫耐药的关系。方法应用R显带技术对染色体进行核型分析,并选用BCR/ABL探针,通过双色荧光原位杂交技术进一步确认遗传学分析。结果患者经格列卫治疗后染色体核型由t(9;22)(q34;q11)变为t(21;22)(p11;q11)。双色荧光原位杂交证实此患者核型应为46,XY,t(9;22;21)(q34;q11;p11)。结论变异Ph易位中ABL-BCR的表达缺失与获得性格列卫耐药有关,荧光原位杂交技术在检测变异易位中起重要作用。     

微滴数字PCR技术检测先天性心脏病患儿染色体22q11．2区段微缺失CSCD

目的探索一种检测22qii．2微缺失综合征的新方法。方法针对22q11．2微缺失综合征特异缺失区内的TBX1基因和内参基因RPP30设计引物和探针,采用微滴数字PCR（dropletdigitalPCR,ddPCR）的方法计算TBX1／RPP30的比值,检测22q11．2区段微缺失。结果通过数字PCR方法计算TBX1／尺PP30的比值检测22q11．2微缺失综合征,检出3例微阵列比较基因组杂交检测结果为22q11．2微缺失综合征阳性的样本。在14例临床诊断为先天性心脏病的患儿中检测出2例22q11．2微缺失阳性样本。结论微滴数字PCR可以准确检测出22q11．2区段微缺失,可提供一种快速、经济的检测先天性心脏病相关染色体22q11．2微缺失综合征的方法。     

先天性心脏病患者22q11微缺失检测及相关分析

目的探讨5个短串联重复（short tandem repeat，STR）标记用于检测22q11微缺失的可行性，了解中国汉族未经挑选的先天性心脏畸形患者中22q11微缺失的发生情况。方法选择位于22q11缺失区域的5个STR标记，对163例中国汉族先天性心脏畸形（congenital heart defect，CHD）息者及双亲进行单倍型分析，对检出的阳性病例及部分阴性病例进行荧光原位杂交（fluorescence in situ hybridization，FISH）验证。结果5个标记均具有较好的信息量，22D_4_1和22D_4_2杂合率分别为0．65和0．52，22D_4_3、22D_4_4和D22S873杂合率均在0．7以上，可用于汉族人群多态性分析；163例先天性心脏畸形患者用STR标记检出12例22q11微缺失，其中9例得到FISH检测证实，2例微小缺失和1例远端缺失FISH检测为阴性；CHD患者22q11微缺失检出率为7．36％，室间隔缺损微缺失检出率为8．18％（9／110），法乐氏四联征检出率为14．3％（3／21），其它类型的CHD未检出缺失。结论5个STR标记可用于汉族人群22q11微缺失的检测，且有快速、成本低的优点；中国汉族CHD患者中存在一定比率的22q11微缺失，尤其是室间隔缺损和法乐氏四联征较为常见。     

t(11;18)染色体易位对于胃黏膜相关淋巴组织淋巴瘤的预后价值

目的 探讨t(11;18)(q21;q21)染色体易位对于胃黏膜相关淋巴组织(mucosal associated lymphoid tissue,MALT)淋巴瘤预后意义.方法 采用回顾性方法对1994年1月至2004年6月间,经术后病理明确诊断的36例MALT淋巴瘤患者进行随访,同时采用间期荧光原位杂交技术检测患者保存的石蜡手术标本有无t(11;18)(q21;q21)染色体易位.结果 36例患者中15例检出t(11;18)(q21;q21)染色体易位,阳性率为41.67％;35例随访至2010年3月,总的中位生存期87个月,伴有t(11;18)(q21;q21)染色体易位者的中位生存期为43个月,无t(11;18)(q21;q21)染色体易位者的中位生存期为130个月,两组之间差异有统计学意义(x2 =29.57,P＜0.01).结论 t(11;18)(q21;q21)染色体易位是MALT淋巴瘤的重要预后因素.     

一例21号环状染色体综合征的细胞遗传学和表型定位分析

目的通过对1例21号环状染色体综合征患者的细胞遗传学分析，探讨21号环状染色体的形成原因，临床表型与染色体区带的关系。方法应用染色体G带、C带、N带、高分辨显带和荧光原位杂交技术对21号环状染色体进行识别与定位。结果患儿双亲核型正常，患儿核型为46，XY，r（21）[91]／46，XY，r（21；21）（p11q22．3；p11q22．3）[5]／45，XY，-21[4]。结论21号环状染色体综合征的临床表现与21q末端缺失的多少相关，男性性别发育异常可能与21q22．3片段的缺失相关。     

多重连接依赖的探针扩增技术在检测胎儿先天性心脏病遗传学病因中的应用

目的探讨多重连接依赖的探针扩增技术（MLPA）用于检测胎儿先天性心脏病遗传学病因的可行性。方法 2006年11月至2009年12月间,共收集34例超声发现为先天性心脏病胎儿的脐血进行染色体核型分析,同时提取脐血淋巴细胞DNA后进行MLPA检测。选取先前已进行核型分析及MLPA确诊的32例标本作为对照,其中包括13-三体、16-三体、18-三体、21-三体、21-三体合并22q11微扩增以及不同范围的22q11微扩增或微缺失。结果 66例标本中,本实验所用的MLPA探针共检出3例13-三体、7例18-三体、10例21-三体、1例21-三体合并22q11微扩增。5例22q11微缺失的缺失范围与已知结果吻合。在34例新收集标本的检测中,提示2例为22q11微缺失（3Mb）,随后通过ML-PA-P250探针组进行检测得到进一步验证。所有标本中有5例16-三体、1例三倍体（69,XXX）以及一例平衡易位未被MLPA检出。结论 MLPA-P290可用于检测可导致先天性心脏病的常见非整倍体及微缺失、微扩增异常,且具有高效、价廉等优点,有较好的临床应用价值。     

Assessment of the frequency of the 22q11 deletion in Afrikaner schizophrenic patients.

A hemizygous deletion of the q11 band on chromosome 22 occurs in 1 of every 5,950 live births (0.017%). The deletion is mediated by low copy repeats (LCRs) flanking this locus. Presence of the deletion is associated with variable phenotypic expression, which can include distinctive facial dysmorphologies, congenital heart disease and learning disabilities. An unusually high percentage of individuals with this deletion (25-30%) have been described to develop schizophrenia or schizoaffective disorder. In previous studies, the prevalence of the 22q11 deletion in patients with schizophrenia was found to be approximately 2% in Caucasian adults and 6% in childhood-onset cases. Both these frequencies represent a dramatic increase from the prevalence of the deletion in the general population. In this study, we investigate the occurrence of the 22q11 deletion in an independent sample of schizophrenic patients of Afrikaner origin. We first ascertained a sample of 85 patients who meet full diagnostic criteria for schizophrenia for presence of two or more of the clinical features associated with presence of the 22q11 deletion. A group of six patients (7%) met these criteria. This group was subjected to fluorescent in situ hybridization (FISH) and presence of the 22q11 deletion was confirmed for two subjects. Our study therefore confirms the previously reported rate of 2% frequency of the 22q11 deletion in adult schizophrenic patients and provides a two-stage screening protocol to identify these patients.     

Chromosome abnormalities in congenital heart disease

Refinements in cytogenetic techniques have promoted progress in understanding the role that chromosome abnormalities play in the cause of congenital heart disease. To determine if mutations at specific loci cause congenital heart disease, irrespective of the presence of other defects, and to estimate the prevalence of chromosome abnormalities in selected conotruncal cardiac defects, we reviewed retrospectively cytogenetic and clinical databases at St. Louis Children's Hospital. Patients with known 7q11.23 deletion (Williams syndrome), Ullrich-Turner syndrome (UTS), and most autosomal trisomies were excluded from this analysis. Two groups of patients were studied. Over a 6.5-year period, 57 patients with chromosomal abnormalities and congenital heart disease were identified. Of these, 37 had 22q11 deletions; 5 had abnormalities of 8p; and 15 had several other chromosome abnormalities. The prevalence of chromosome abnormalities in selected conotruncal or aortic arch defects was estimated by analysis of a subgroup of patients from a recent 22-month period. Chromosome abnormalities were present in 12% of patients with tetralogy of Fallot, 26% in tetralogy of Fallot/pulmonary atresia, 44% in interrupted aortic arch, 12% in truncus arteriosus, 5% in double outlet right ventricle, and 60% in absent pulmonary valve. We conclude that chromosome analysis should be considered in patients with certain cardiac defects. Specifically, fluorescent in situ hybridization (FISH) analysis of 22q11 is indicated in patients with conotruncal defects or interrupted aortic arch. High resolution analysis should include careful evaluation of the 8p region in patients with either conotruncal or endocardial cushion defects. Am. J. Med. Genet. 70:292–298, 1997. © 1997 Wiley-Liss, Inc.     

22q11.2 deletions in a series of patients with non-selective congenital heart defects: incidence, type of defects and parental origin

Previous studies have indicated a wide spectrum of incidences of 22q11.2 deletions in isolated and syndromic (sporadic or familial) cases of conotruncal heart defects, whereby the detection rate of the deletion varied from 65% in one study to 0 in another. We analysed 110 patients with non-selective syndromic or isolated non-familial congenital heart malformations by fluorescence in situ hybridization (FISH) using the D22S75 DiGeorge chromosome (DGS) region probe. A 22q11.2 microdeletion has been detected in 9/51 (17.6%) syndromic patients. Five were of maternal origin and four of paternal origin. None of the 59 patients with isolated congenital cardiac defect had a 22q11.2 deletion. We compared the cardiac anomalies of our patients with a 22q11.2 deletion with those of previously published series and we describe types of congenital heart defects which appear to be often associated with a 22q11.2 deletion. The ability to detect such types of heart defects and to provide an early diagnosis of 22q11.2 deletion is particularly relevant in very young infants, who often show only very mild expression of the otherwise well-characterized phenotypes of the DiGeorge/velo–cardio–facial syndrome (DG/VCFS).     

Congenital heart defects in a novel recurrent 22q11.2 deletion harboring the genes CRKL and MAPK1

The proximal region of the long arm of chromosome 22 is rich in low copy repeats (LCR). Non-allelic homologous recombination (NAHR) between these substrates explains the high prevalence of recurrent rearrangements within this region. We have performed array comparative genomic hybridization in a normally developing girl with growth delay, microcephaly, and truncus arteriosus, and have identified a novel recurrent 22q11 deletion that spans LCR22-4 and partially affects the common 22q11.2 deletion syndrome and the distal 22q11 deletion syndrome. This deletion is atypical as it did not occur by NAHR between any of the major LCRs found on 22q11.2. However, the breakpoint containing regions coincide with highly homologous regions. An identical imbalance was reported previously in a patient with striking phenotypic similarity. Computational gene prioritization methods and biological evidence denote the genes CRKL and MAPK1 as the highest ranking candidates for causing congenital heart disease within the deleted region.     

Clinical and molecular cytogenetic studies in ring chromosome 5: report of a child with congenital abnormalities

We report here a child with a ring chromosome 5 (r(5)) associated with facial dysmorphology and multiple congenital abnormalities. Fluorescent in situ hybridization (FISH) using bacterial artificial chromosome (BAC) clones was performed to determine the breakpoints involved in the r(5). The 5p deletion extended from 5p13.2-3 to 5pter and measured 34.61 Mb (range: 33.7-35.52 Mb) while the 5q deletion extended from 5q35.3 to 5qter and measured 2.44 Mb (range: 2.31-2.57 Mb). The patient presented signs such as microcephaly, hypertelorism, micrognathia and epicanthal folds, partially recalling those of a deletion of the short arm of chromosome 5 and the "cri-du-chat" syndrome. The most striking phenotypic features were the congenital heart abnormalities which have been frequently reported in deletions of the distal part of the long arm of chromosome 5 and in rings leading to a 5q35-5qter deletion. However, the NKX2-5 gene, which has been related to congenital heart defects, was not deleted in our patient, nor presumably to some other patients with 5q35.3-5qter deletion. We propose that VEGFR3, deleted in our patient, could be a candidate gene for the congenital heart abnormalities observed.     

Prenatal diagnosis of tetralogy of Fallot associated with chromosome 22q11 deletion

Microdeletion of 22q11 is responsible for DiGeorge syndrome, velocardiofacial syndrome, congenital conotruncal heart defects, and related disorders. We report our experiences on prenatal diagnosis by fluorescence in situ hybridization (FISH) for 22q11 deletion in two fetuses with tetralogy of Fallot. Karyotyping and FISH of the parents revealed that one fetus inherited the disease from maternal microdeletion. These findings suggest the importance of performing FISH in pregnancies with prenatally detected tetralogy of Fallot.     

Vasomotor instability in neonates with chromosome 22q11 deletion syndrome

Approximately 70% of individuals with chromosome 22q11 deletion syndrome (22q11DS) have congenital heart defects. A host of other vascular problems in these patients, such as tortuous carotid arteries, Raynaud's phenomenon, unexplained hypotension, hypertension, and hypothermia, raise the possibility that there may be abnormal autonomic regulation of the vascular system. So far, however, there has been no formal report of autonomic dysfunction in patients with 22q11 deletion. We present two infants with 22q11DS, who had profound hypotension after uncomplicated surgeries for congenital heart disease. The hypotension was not responsive to vasopressor treatment (and extracorporeal membrane oxygenation in one infant) and resulted in death, due to multiorgan system failure. Obvious causes, such as poor cardiac contractility, prolonged circulatory arrest, neurological abnormality, sepsis and blood loss were excluded. On autopsy, no abnormalities were found that could explain the hypotension. We hypothesize that these infants died of severe hypotension due to abnormal vascular tone and that this is a variable feature in individuals with 22q11 deletion. The autonomic nervous system, which is responsible for the regulation of vasomotor tone, may be variably affected in 22q11DS. This could have implications for the surgical management of patients with 22q11DS. Further studies on this topic would establish or refute the association between 22q11DS and dysautonomia.     

Kabuki syndrome is not caused by a microdeletion in the DiGeorgeVelocardiofacial chromosomal region within 22q11.2

Kabuki syndrome (KS) or Niikawa-Kuroki syndrome is a sporadic disorder characterized by postnatal growth retardation, developmental delay, mild to moderate retardation, and a characteristic facial appearance. Cardiovascular defects, clefts of the lip, palate, or both, and musculoskeletal abnormalities occur in about 50% of patients with KS. The cause of this multiple congenital anomaly syndrome is unknown, and investigators have speculated that KS is a contiguous gene-deletion syndrome. Based on the presence of congenital heart defects in patients with KS, it was suggested that this disorder might share a common cause with the 22q11 deletion syndromes. A preliminary study of 2 patients with KS failed to detect a deletion within 22q11. We report the results of fluorescence in situ hybridization with cosmid probes for loci D22S75 (N25) and D22S259 (R32) within the DiGeorge chromosomal region (DGCR) on metaphase spreads from an additional 5 patients, 2 non-Japanese and 3 Japanese, with KS. None of the 5 had deletions at either locus. It is unlikely that KS is caused by a deletion within 22q11. © 1996 Wiley-Liss, Inc.