17q12染色体微缺失综合征产前诊断分析

目的:通过分析17q12染色体微缺失综合征的临床资料,探讨该综合征的胎儿期临床表型谱和产前诊断方法,为17q12染色体微缺失综合征患者及携带者的遗传学咨询及产前诊断提供依据。方法:选取2018年1月至2019年6月因超声检查发现胎儿肾脏皮质回声增强就诊于河南省人民医院产前诊断中心的患者。经羊水取样,并行染色体微阵列分析(CMA)。结果:CMA检测共发现胎儿17 q12微缺失综合征者5例,缺失片段1.18～1.52Mb,缺失区域与肾囊肿和糖尿病综合征致病区域部分重叠(chr17:34815072-36215917)。结论:对于超声检测出肾脏异常的胎儿,无论其是否合并其它畸形,均应行染色体核型和CMA检查,以及时确诊17q12染色体微缺失综合征胎儿,为胎儿出生后临床表现提供理论支持,为孕妇及家庭提供更为精准的遗传咨询。     

22q11微缺失综合征的产前诊断

22q11微缺失综合征的临床表型变异范围广泛,其典型的临床表现是心脏畸形,面容异常,胸腺发育不全,腭裂和低钙血症.进行产前诊断的人群主要是:曾经有22q11微缺失综合征孕产史的夫妇,自身是22q11微缺失患者的夫妇和宫内监测到妊娠胎儿有心脏锥干畸形者.产前诊断的方法主要有:常规染色体核型分析,荧光原位杂交,多重PCR,实时定量PCR和微阵列-比较基因组杂交.     

5p15缺失综合征合并4q32重复1例临床分析与基因诊断

目的 探讨5p15缺失综合征合并4q32重复的临床特征及分子遗传学特点.方法 回顾分析1例5p15缺失综合征合并4q32重复患儿的临床资料以及分子遗传学分析资料.结果 10月龄女性患儿,具有特殊面容、发育迟缓、先天性心脏病及喉软骨发育不良等临床表现.全外显子测序和染色体组拷贝数分析精确定位拷贝数异常改变的染色体片段区域...     

22q11.2微缺失综合征7例相关临床表型及病因分析

目的　探讨22q11.2微缺失综合征患儿的不同临床表现。方法　收集2006年7月至2007年6月在英国Oxford 儿童医院临床所见的7例经分子细胞遗传学分析（FISH检测）确诊为22q11.2微缺失综合征患儿的临床资料,分析其临床表现、诊断及治疗情况。结果　7例中男2例,女5例。7例均通过FISH检测确诊,1例为产前诊断,余6例的平均确诊年龄为2个月。2例（28.4%）为父母遗传致病,5例（71.6%）为基因突变致病。其中,先天性心脏病和面容异常的发生率均为100%,免疫功能异常28. 6%,颚裂14.3%,低钙14.3%。根据患儿的不同临床表现进行对症治疗。结论　22q11.2微缺失综合征患儿以心脏畸形及面容异常为突出表现,结合FISH检测可早期诊断,基因突变是其主要病因,以流出道受损为主的心脏畸形及以T淋巴细胞数量减少为主的免疫功能异常是影响预后的关键因素。     

应用CMA诊断14q32微缺失综合征

目的 探讨14q32微缺失综合征的临床表现,进一步提高对该疾病的认识及对该疾病的产前及遗传学诊断.方法 对1例因"出生后口吐白沫伴气促1天"入院的胎儿进行遗传学诊断,结合常规染色体G显带分析及单核苷酸多态性微阵列(single nucleotide polymorphism array,SNP-array)技术进行分子...     

2例胎儿15号小额外标记染色体产前遗传学分析

目的:探讨染色体微阵列分析(CMA)诊断15q小额外标记染色体胎儿的临床价值。方法:获得2例高危孕妇的胎儿羊水或脐血细胞及其双亲外周血细胞,通过CMA和G显带染色体核型分析检测胎儿及其父母的染色体结构。结果:胎儿1:羊水细胞G显带核型分析结果为47,XX,+mar,CMA结果为arr15q11.2(22770421-23288350)×4,其父外周血细胞G显带核型分析结果为47,XY,+mar,母亲外周血染色体核型结果及CMA检测结果未见明显异常。胎儿2:脐血染色体G显带分析结果为47,XX,+mar,CMA结果为arr15q11.2q13.3(22770421-32439524)×4,其父母外周血染色体核型结果及CMA分析结果未见明显异常。结论:通过CMA检测和G显带核型分析结果显示,胎儿1存在15q11.2区域的四拷贝重复变异,经鉴定此携带小额外标记染色体为健康人群多态性。胎儿2存在15q11.2q13.3四拷贝重复小额外标记染色体,确诊为15q11.2q13.3微重复四倍体综合征,出生后可能引起较严重的异常表型。本文对两例15号染色体微重复胎儿进行了产前诊断,明确了胎儿基因型与表型的对应关系,为临床产前诊断和遗传咨询提供可靠的依据。     

1例Rubinstein-Taybi综合征的临床分析及文献复习

本文报道1例CREBBP基因变异导致Rubinstein-Taybi综合征的临床特征及CREBBP基因突变特点.患儿女,2岁,主要表现为精神运动发育迟缓,伴双手拇指及第一脚趾粗大.全外显子测序显示患儿CREBBP基因存在碱基缺失c.3469_3471del,p.val1157del(杂合),父母该位点为正常基因型,提示...     

胎儿畸形与22q11微缺失相关性的研究进展

22q11微缺失综合征是由于22号染色体长臂近着丝粒端微片段22q11.21~q11.23缺失引起的遗传综合征,是常见的遗传学疾病,在新生活产儿中发病率为1/4000[1],其主要表现为Di George综合征（DGS）：甲状旁腺发育不全、胸腺发育不全和锥干型心脏畸形（conotruncal defects,CTD）;     

3例超声肾脏异常胎儿临床及遗传学分析

目的:明确3例肾脏异常胎儿的遗传学病因.方法:采集胎儿羊水及其父母外周血行染色体核型分析及单核苷酸多态性微阵列(SNP-array)检测.结果:3个家系胎儿产前超声均提示胎儿肾脏异常,SNP-array检测结果提示3个家系胎儿在17号染色体17 q12区段存在1.4-1.5 Mb片段缺失.家系1及家系2父母芯片验证结果...     

516例无精症Y染色体微缺失及细胞遗传学分析

目的 探讨Y染色体微缺失和细胞遗传学分析在无精症中的相关性.方法 对2015年3月至2019年12月来广东省妇幼保健院就诊的诊断为无精症的患者进行外周血染色体G显带核型分析,运用多重定量荧光聚合酶链反应(quantitative fluorescent PCR,QF-PCR)技术检测Y染色体上的无精因子(azoospe...     

Molecular cytogenetic characterization of Jacobsen syndrome (11q23.3-q25 deletion) in a fetus associated with double outlet right ventricle,hypoplastic left heart syndrome and ductus venosus agenesis on prenatal ultrasound

Objective

We present molecular cytogenetic characterization of Jacobsen syndrome (11q23.3-q25 deletion) in a fetus associated with double outlet right ventricle (DORV), hypoplastic left heart syndrome (HLHS), and ductus venosus (DV) agenesis on prenatal ultrasound.

Prenatal diagnosis and molecular cytogenetic characterization of chromosome 22q11.2 deletion syndrome associated with congenital heart defects

ObjectiveTo report prenatal diagnosis of 22q11.2 deletion syndrome in a pregnancy with congenital heart defects in the fetus.Case reportA 26-year-old, primigravid woman was referred for counseling at 24 weeks of gestation because of abnormal ultrasound findings of fetal congenital heart defects. The Level II ultrasound revealed a singleton fetus with heart defects including overriding aorta, small pulmonary artery, and ventricular septal defect. Cordocentesis was performed. The DNA extracted from the cord blood was analyzed by multiplex ligation-dependent amplification (MLPA). The MLPA showed deletion in the DiGeorge syndrome (DGS) critical region of chromosome 22 low copy number repeat (LCR) 22-A∼C. Conventional cytogenetic analysis revealed a normal male karyotype. Repeated amniocentesis and cordocentesis were performed. Whole-genome array comparative genomic hybridization (aCGH) on cord blood was performed. aCGH detected a 3.07-Mb deletion at 22q11.21. Conventional cytogenetic analysis of cultured amniocytes revealed a karyotype 46,XY. Metaphase fluorescence in situ hybridization (FISH) analysis on cultured amniocytes confirmed an interstitial 22q11.2 deletion.ConclusionPrenatal ultrasound findings of congenital heart defects indicate that the fetuses are at increased risk for chromosome abnormalities. Studies for 22q11.2 deletion syndrome should be considered adjunct to conventional karyotyping. Although FISH has become a standard procedure for diagnosis of 22q11.2 deletion syndrome, MLPA can potentially diagnose a broader spectrum of abnormalities, and aCGH analysis has the advantage of refining the 22q11.2 deletion breakpoints and detecting uncharacterized chromosome rearrangements or genomic imbalances.     

Screening for 22q11.2 deletion syndrome by two non-invasive prenatal testing methodologies: A case with discordant results

Objective

Non-invasive prenatal testing (NIPT) through the analysis of cell-free DNA in maternal plasma has bee expanded to include clinically-relevant microdeletions such as the 22q11.2 deletion syndrome (22q11.2DS).

Prenatal diagnosis of familial 22q11.2 deletion syndrome in a pregnancy with concomitant cardiac and urinary tract abnormalities in the fetus and the mother

ObjectiveWe present prenatal diagnosis of familial 22q11.2 deletion syndrome in a pregnancy with concomitant cardiac and urinary tract abnormalities in the fetus and the mother.Case reportA 28-year-old woman primigravid underwent amniocentesis at 23 weeks of gestation because of fetal ultrasound findings of aortic stenosis, interrupted aortic arch (IAA), left multicystic kidney, right hydronephrosis and ureterocele. Amniocentesis revealed a karyotype of 46,XX. Simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed the result of arr 22q11.21 (18,894,835-21,505,417) × 1.0 [GRCh37 (hg19)] with a 2.611-Mb 22q11.21 deletion encompassing 41 Online Mendelian Inheritance in Man (OMIM) genes including UFD1L, TBX1, GNB1L, COMT and MED15. aCGH analysis on the DNAs extracted from parental bloods confirmed that the mother carried the same 22q11.21 microdeletion. Level II ultrasound additionally found ventricular septal defect (VSD) and persistent left superior vena cava (PLSVC). Examination of the woman showed short stature, malar hypoplasia, hypertelorism, bulbous nasal tip, prominent nasal root, hypoplasia of nasal wings, right renal agenesis, left ureterovesical reflux and VSD with repair, but normal intelligence and normal neuropsychiatric development. The woman decided to continue the pregnancy, and a 2903-g female baby was delivered at 38 weeks of gestation with left multicystic kidney, right hydronephrosis, dysgenesis of corpus callosum, IAA, VSD, PLSVC, patent ductus arteriosus, patent foramen ovale, atrial septal defect, dilated main pulmonary artery and tricuspid regurgitation. The neonate died at the age of one month.ConclusionPrenatal diagnosis of concomitant congenital heart defects and urinary tract abnormalities in the fetus and the parent should raise a suspicion of familial 22q11.2 deletion syndrome.     

Prenatal diagnosis of 17q12 duplication and deletion syndrome in two fetuses with congenital anomalies

ObjectiveThe objective of this study was to characterize the genetic abnormalities in two fetuses with congenital anomalies in prenatal screening.Materials and methodsThe mother of Fetus 1 was 26 years old and had a second trimester serum screening that indicated the fetus was at low risk. The prenatal ultrasound and magnetic resonance imaging (MRI) at 28 weeks of gestation showed mild ventriculomegaly, microcephaly, and agenesis of the corpus callosum. The mother of Fetus 2 was 25 years old and also had a second trimester serum screening that indicated the fetus was at low risk. The prenatal ultrasound at 32 weeks of gestation showed the presence of hyperechogenic and enlarged kidneys with multicystic renal dysplasia bilaterally and a persistent left superior vena cava (PLSVC). Both pregnant women underwent cord blood samplings because of the abnormal imaging results. Karyotype analysis revealed normal results in the two fetuses. Chromosome microarray analysis (CMA) was then performed to provide genetic analysis of the cord blood and parental blood samples. Ultimately, the pregnancies were both terminated.ResultsCMA detected a 1.56-Mb duplication at 17q12 in Fetus 1 and a 1.93-Mb deletion of 17q12 in Fetus 2. Both the duplicated and deleted regions included the HNF1B and LHX1 genes. Neither the duplication nor deletion was inherited from the parents.ConclusionThis study is the first to report the prenatal diagnosis of a 17q12 duplication syndrome. Our results further confirmed that genes in this region, including HNF1B and LHX1, are essential for normal brain and kidney development, and also indicated some genes that may be associated with the cardiovascular abnormality. Combined with imaging examination, the use of CMA will improve the diagnosis of submicroscopic chromosomal aberrations in fetuses with congenital anomalies.     

Fish based preimplantation genetic diagnosis to prevent DiGeorge syndrome

Purpose  

To report the performance of fluorescence in-situ hybridization in the setting of preimplantation genetic diagnosis in order to diagnose embryos affected by DiGeorge syndrome.     

Mutational Screening and Prenatal Diagnosis in Cornelia de Lange syndrome

Phenotypic variability and the lack of a diagnostic marker have complicated the rapid diagnosis and genetic counseling for Cornelia de Lange syndrome (CdLS). The clinical features of CdLS are striking and easily recognizable by characteristic facial dysmorphism, upper-extremity malformations, hirsutism, cardiac defects, growth and cognitive retardation, and gastrointestinal abnormalities with severe mental retardation. The molecular diagnosis is essential for predicting prognosis and genetic counseling in the affected family, especially while planning the next pregnancy. We report here from India six cases of CdLS and how precise mutational screening in two cases helped in prenatal diagnosis and proved significant in prevention of recurrence in the affected family.     

Molecular cytogenetic characterization of de novo concomitant proximal 21q deletion of 21q11.2q21.3 and distal Xp deletion of Xp22.33p22.2 due to an unbalanced X;21 translocation detected by amniocentesis

ObjectiveWe present molecular cytogenetic characterization of de novo concomitant proximal 21q deletion of 21q11.2q21.3 and distal Xp deletion of Xp22.33p22.2 due to an unbalanced X; 21 translocation detected by amniocentesis.Case reportA 35-year-old, primigravid woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 45,X,der(X)t(X; 21) (p22.2; q21.3),-21. Simultaneous array comparative genomic hybridization (aCGH) revealed the result of an 11.9-Mb Xp22.33p22.2 deletion encompassing HCCS, SHOX, AMELX and OFD1 and a 15.4-Mb 21q11.2q21.3 deletion encompassing NRIP1 and APP. The pregnancy was subsequently terminated, and a malformed fetus was delivered with craniofacial dysmorphism. The parental karyotypes were normal. Polymorphic DNA marker analysis by quantitative fluorescence polymerase chain reaction (QF-PCR) confirmed a paternal origin of the 21q proximal deletion. Cytogenetic analysis of cord blood confirmed the karyotype of 45,X,der(X)t(X; 21) (p22.2; q21.3),-21. aCGH analysis of the cord blood confirmed the prenatal diagnosis.ConclusionQF-PCR analysis is useful for determination of the parental origin of a de novo unbalanced X; autosome translocation detected by prenatal diagnosis. The information acquired is useful for genetic counseling under such a circumstance.