Maternal origin and clinical findings in a case with trisomy 22

We report a newborn girl with multiple congenital anomalies whose chromosomal analysis showed complete trisomy 22. Her phenotype included microcephaly, epicanthus, hypertelorism, micrognathia, cleft palate, microtia, and preauricular tag. She died in the 24th post-natal hour. Trisomy 22 was shown by fluorescence in situ hybridization technique and the parental origin of the extra chromosome was found to be maternal by DNA microsatellite marker analysis of chromosome 22. Postmortem examination revealed the presence of atrioseptal defect and stasis in the biliary canals. We believe that this patient will contribute to the literature both by clinical findings and short life span associated with maternal origin of extra chromosome 22.     

The Contribution of Chromosomal Abnormalities to Congenital Heart Defects: A Population-Based Study

We aimed to assess the frequency of chromosomal abnormalities among infants with congenital heart defects (CHDs) in an analysis of population-based surveillance data. We reviewed data from the Metropolitan Atlanta Congenital Defects Program, a population-based birth-defects surveillance system, to assess the frequency of chromosomal abnormalities among live-born infants and fetal deaths with CHDs delivered from January 1, 1994, to December 31, 2005. Among 4430 infants with CHDs, 547 (12.3%) had a chromosomal abnormality. CHDs most likely to be associated with a chromosomal abnormality were interrupted aortic arch (type B and not otherwise specified; 69.2%), atrioventricular septal defect (67.2%), and double-outlet right ventricle (33.3%). The most common chromosomal abnormalities observed were trisomy 21 (52.8%), trisomy 18 (12.8%), 22q11.2 deletion (12.2%), and trisomy 13 (5.7%). In conclusion, in our study, approximately 1 in 8 infants with a CHD had a chromosomal abnormality. Clinicians should have a low threshold at which to obtain testing for chromosomal abnormalities in infants with CHDs, especially those with certain types of CHDs. Use of new technologies that have become recently available (e.g., chromosomal microarray) may increase the identified contribution of chromosomal abnormalities even further.     

Atrioventricular septal defect--associated anomalies and aneuploidy in prenatal life

The present study was conducted to estimate the frequency of other-cardiac, extracardiac and chromosomal anomalies in fetuses with A VSD diagnosed in a prenatal diagnosis center, analysed from the database during the 54-month period extending from November 1997 to May 2002. One hundred and three fetuses were diagnosed with A VSD. Among them other-cardiac and extra cardiac anomalies were present in 56 and 75 cases respectively. Of the 22 fetuses that had undergone karyotyping, no metaphase was seen in one case. In the remaining 21, 15 (71.4%) turned out to be normal, three (14.2%) had trisomy 18, two (9.5%) had trisomy 13 and one had trisomy 21 (4.8%). We found that AVSD almost always occurs with other-cardiac or extracardiac anomalies, though the pattern may differ between populations. It seems to be less frequently associated with chromosomal anomalies (especially trisomy 21) in South India. The genetics of AVSD underscores the importance of a thorough understanding of the target population in prenatal decision-making.     

胎儿右位主动脉弓与染色体异常的相关性分析

目的：对系统超声检出胎儿右位主动脉弓与染色体异常的相关性进行分析。方法采集2009年1月至2014年12月在我院进行系统超声产前筛查19例右位主动脉弓胎儿,所有入选右位主动脉弓胎儿均进行羊水穿刺进行染色体核型分析,评价系统超声检测出的胎儿右位主动脉弓与染色体异常之间的相关性。结果15例右位主动脉弓超声像图表现气管和食管被气管左侧的动脉导管和气管后方的迷走左锁骨下动脉围成一“U”字形血管结构;1例胎儿有双主动脉弓超声主要表现为气管和食管被左右两侧的主动脉弓环绕成一个“O”字形包绕;3例右位主动脉弓胎儿另有左位动脉导管及头臂动脉影像分支,超声图主要表现为动脉导管在三血管-气管切面上并未有显示出来,气管的前方是动脉导管,未形成血管环;19例右位主动脉弓胎儿均进行染色体核型分析,3例伴室间隔缺损、单心房、三尖瓣闭锁、肺动脉狭窄,核型为18-三体;4例伴室间隔缺损、完全性房室通道、单心房、右室双出口、肺动脉狭窄近闭锁,核型为18-三体;3例伴单心室、单心房,核型为21-三体;1例法洛四联症和1例右位心、主动脉狭窄,伴有22q11.2。结论在产前胎儿超声筛查中要重视三血管-气管切面上的超声图像,有助于提高右位主动脉弓的检出率,胎儿右位主动脉弓与18-三体、21-三体等染色体病有明显相关性,若发现胎儿右位主动脉弓,应进行染色体核型进一步分析,排除染色体病变,从而达到优生优育的目的。     

Partial trisomy of chromosome 10 inherited from a carrier father

Partial trisomy of chromosome 10q is a very rare condition with only four cases having been reported in the literature. This report describes a neonate with symmetric growth retardation and multiple dysmorphic features, in whom G-banded chomosomal analysis revealed a partial trisomy of chromosome 10q (q2.4-q ter). The father was diagnosed as a carrier of a balanced translocation with a karyotype of 46, XY t(10.3) (q2.4L: pter). In patients with a bad obstetric history, genetic counselling prior to a new conception cna aid in early prenatal diagnosis of fetuses with recurrent chromosomal abnormalities by means of fetal tissue sampling.     

Trisomy 3q2 and Pierre-Robin sequence in a boy with unbalanced 46,XY, der(10), t(3;10)(q23;q26.3) de novo karyotype

A partial trisomy of the long arm of chromosome number 3 (3q23----3qter) is reported in a malformed male newborn with a Pierre-Robin sequence. The importance of the detection of chromosomal abnormalities towards the nosology of malformation sequences is discussed.     

The neonatal recognition of partial 11q trisomy (previously 'Trisomy 22')

The recognition of chromosomal abnormalities in the neonatal period is important. Paediatricians should be aware that the partial Trisomy 22'(now partial 11 q trisomy) syndrome has a recognizable phenotypic expression and is relatively common. The distinctive fades with a long philtrum, micrognathia, beaked nose and deft palate, associated with hypotonia and other congenital abnormalities, should make early postnatal diagnosis possible so that parental counselling can be given without delay.     

The neonatal recognition of partial 11q trisomy (previously 'trisomy 22')

The recognition of chromosomal abnormalities in the neonatal period is important. Paediatricians should be aware that the partial 'Trisomy 22' (now partial 11q trisomy) syndrome has a recognizable phenotypic expression and is relatively common. The distinctive facies with a long philtrum, micrognathia, beaked nose and cleft palate, associated with hypotonia and other congenital abnormalities, should make early postnatal diagnosis possible so that parental counselling can be given without delay.     

Reasons for trisomy 13 or 18 births despite the availability of prenatal diagnosis and pregnancy termination

BACKGROUND: Few studies have evaluated the reasons why lethal chromosomal anomalies continue to occur despite the importance of this question for maximizing perinatal care. AIMS: To determine why trisomy 13 or 18 births continue to occur in Alaska. STUDY DESIGN: Case series involving review of maternal and infant medical records. SUBJECTS: All 28 known infants and fetuses that died with trisomy 13 or 18 during 1992-2001 and their mothers. OUTCOME MEASURES: The proportion of mothers that declined or received a variety of routine prenatal tests, the results of prenatal testing, and the impact of testing on decisions related to pregnancy. RESULTS: Seventeen women declined pregnancy termination or amniocentesis, 10 had no prenatal risk factors and were not offered these procedures, and one woman had an amniocentesis but was not offered pregnancy termination. Twenty-six women had >/=1 prenatal ultrasounds; for 17 women, these were interpreted as normal throughout pregnancy (n=11) or until after 30 weeks gestation (n=6) despite substantial fetal malformations. Fourteen of 15 women with an abnormal ultrasound had an amniocentesis compared to one of eight women whose only risk factor was advanced maternal age. CONCLUSIONS: Most trisomy 13 or 18 deliveries occurred to women who declined amniocentesis or pregnancy termination. Failure to identify abnormalities on prenatal ultrasound may have contributed to the decision not to have these procedures.     

A population study of chromosome 22q11 deletions in infancy

AIMS: To determine the prevalence of submicroscopic deletions within chromosome band 22q11 in infants with significant heart disease and compare this with the prevalence of other chromosomal abnormalities causing significant heart disease. To determine a minimum prevalence of deletions within chromosome band 22q11 in infants in the general population. METHODS: Chromosome analysis was performed on samples from infants born in the former UK Northern Health Region in 1994 and 1995 who either had significant heart disease or who were suspected to have a chromosome band 22q11 deletion following referral to the Northern Genetics Service. Significant heart disease was defined as major structural malformation or cases where invasive investigation or intervention was required in infancy. RESULTS: Chromosome band 22q11 deletions were identified in nine infants in a population of 69,129 livebirths, giving a minimum prevalence of 13 per 100,000 (95% confidence interval 4.5 to 21.5). Six cases had significant heart disease, one of whom died before diagnosis. In the same population there were 53 cases of trisomy 21, 15 of whom had significant heart disease. CONCLUSION: The most common chromosomal cause of significant congenital heart disease remains trisomy 21, while the second most common chromosomal cause is deletion in chromosome band 22q11.     

Transient myeloproliferative disorder in chromosomally normal newborn infant

Transient myeloproliferative disorder is a condition clinically resembling congenital acute myelogenous leukemia. As in acute leukemias the blast cell population in this disorder may have either normal or abnormal chromosomal complement. Transient myeloproliferative disorder is well recognized in neonates with a complete or mosaic trisomy 21 (Down's syndrome). We report a phenotypically and cytogenetically normal infant with this syndrome in whom only blast cells showed trisomy 21. We postulate that the pathogenesis of the transient myeloproliferative disorder in both Down's syndrome infants and those with a normal chromosomal complement is related to abnormal prenatal production of placental regulatory hemopoietic factors caused by chromosomal defect(s) confined to placental tissues.     

26例胎儿鼻骨发育异常的产前诊断结果分析

目的探讨胎儿鼻骨缺失和发育不良的产前诊断、遗传咨询、临床处理路径。方法2016年12月1日至2017年12月1日,在中国医学科学院北京协和医院产检的孕妇中,发现鼻骨发育异常26例,根据是否合并其他超声异常,分为孤立性和非孤立性鼻骨发育异常两组。所有病例均行产前染色体核型分析及染色体微阵列分析(chromosomal microarray analysis,CMA),回顾性分析两组病例的临床资料、产前遗传学诊断结果和妊娠结局。结果孤立性鼻骨缺失或发育不良共18例,其中14例染色体核型分析及CMA结果未见异常,另4例CMA结果为临床意义不明的拷贝数变异(variants of unknown significance,VUS),偏良性,均继续妊娠,随访新生儿均正常。非孤立性鼻骨缺失或发育不良共8例,1例为21三体,2例为18三体,2例CMA结果为致病性拷贝数变异(copy number variation,CNV)。3例染色体核型分析和CMA均未见异常,其中1例进一步行全外显子测序(whole exome sequencing,WES)分析,提示胎儿为RPGRIP1L基因的复合杂合突变,诊断为Meckel综合征。8例非孤立性鼻骨缺失或发育不良的病例中,7例孕妇选择终止妊娠,另1例双胎之一超声异常,畸形新生儿出生后即夭折。结论对于产前超声发现鼻骨发育异常的病例,无论其是否合并其他超声异常,均建议行包括CMA在内的产前遗传学诊断,必要时进一步行WES分析。     

Severe upper airway stenosis in a boy with partial monosomy 16p13.3pter and partial trisomy 16q22qter

We report the case of a boy with a de novo partial monosomy 16p13-pter and partial trisomy 16q22-qter detected by fluorescence in situ hybridization using subtelomeric probes for 16p and 16q. The boy had facial characteristics, skeletal features, congenital heart defects, an imperforate anus, urogenital malformations, pre/postnatal growth retardation, and psychomotor retardation, most of which have been reported both in partial monosomy 16p and partial trisomy 16q. In addition, he suffered from upper airway stenosis due to possible laryngeal stenosis with subglottic webs. The upper airway stenosis could be a rare complication of partial monosomy 16p or partial trisomy 16q, or a nonspecific malformation resulting from chromosomal abnormalities.     

Dandy-Walker syndrome and chromosomal abnormalities

Dandy-Walker syndrome (DWS) is a brain malformation of unknown etiology, but several reports have been published indicating that there is a causal relationship to various types of chromosomal abnormalities and malformation syndromes. In the present article, we present a bibliographical survey of several previously issued reports on chromosomal abnormalities associated with DWS, including our case of DWS found in trisomy 18. There are various types of chromosomal abnormalities associated with DWS; most of them are reported in chromosome 3, 9, 13 and 18. We also summarize some other chromosomal abnormalities and various congenital malformation syndromes.     

Ocular findings in a case of trisomy 18 with variant of Dandy-Walker syndrome

Trisomy 18 is the second most common chromosomal syndrome and has multiple dysmorphic features. However, ocular findings in trisomy 18 are rarely reported. Retinal folds are the most common ocular finding described to date, although retinal hypopigmentation, dysplasia, and areas of hemorrhage and gliosis are also found in trisomy 18. Dandy-Walker syndrome is a brain malformation that has been reported in association with numerous chromosomal abnormalities, although it has rarely been reported in association with trisomy 18. Here, we present a case of trisomy 18 with ocular pathology and variant of Dandy-Walker syndrome, a combination that has not previously been reported.     

The effects of Down syndrome and other chromosomal abnormalities on survival and management in oesophageal atresia

Recognisable chromosomal abnormalities occur in over 5% of patients with oesophageal atresia (OA). In a review of 670 patients with OA chromosomal abnormalities were identified in 35 (5.2%); of whom 16 had trisomy 18 and 12 had trisomy 21. In patients with trisomy 18, the diagnosis should be suspected on clinical grounds and confirmed on analysis of chromosomes; no active treatment of the OA is justified because of the extremely poor prognosis. In Down syndrome (DS) 50% will have pure OA with no tracheo-oesophageal fistula. In addition, many of these infants will have associated anomalies typical of those normally seen in DS, eg., Hirschsprung's disease, duodenal atresia, and congenital heart disease. Despite treatment, OA with DS has a high mortality.     

Non-invasive prenatal diagnosis by fetal nucleic acid analysis in maternal plasma: the coming of age

Prenatal diagnosis is an important part of obstetrics care. In the current prenatal programmes, definitive diagnosis of fetal genetic or chromosomal conditions is conducted through fetal sampling by amniocentesis or chorionic villus sampling. To obviate the risks of fetal miscarriage that are associated with the invasive sampling procedures, we have been developing non-invasive prenatal diagnostic tests based on cell-free fetal DNA analysis from maternal plasma. To date, fetal sex and rhesus D status determination by circulating fetal DNA analysis is performed clinically in many centres. Strategies for the non-invasive diagnosis of monogenic diseases have been developed. Accurate detection of fetal trisomy 21 by next-generation sequencing has been achieved. Many of the non-invasive prenatal tests could be introduced to the clinics as soon as cost-effective and high throughput protocols are developed.     

Chromosomal basis of recurrent fetal losses

Chromosome abnormalities constitute the single most etiological factor in spontaneous abortions and other fetal losses and include sporadic chromosome abnormalities such as monosomy, trisomy, triploidy, tetraploidy and chromosomal mosaicism. These errors either originate during gametogenesis or after fertilization during the early zygotic divisions. Based upon the information now available it is apparent that if a couple has had two fetal losses, the karyotypes of the abortuses are most likely to be concordant either both being normal or both being abnormal. Fetal losses may also be due to a chromosome abnormality carried by a parent in a clinically silent form such as a balanced translocation. A compilation of cytogenetic data from 17,112 parents (8,743 females and 8,369 males) revealed 517 instances of chromosome abnormalities, an incidence of 3 per cent (6% of couples). Approximately 50 per cent of all chromosome abnormalities detected were balanced reciprocal translocations, followed by balanced Robertsonian translocations (23%) and sex chromosome mosaicism in females (14%). Parental chromosome abnormalities are known to be factors in abnormal gametogenesis and zygote formation, and, therefore, prenatal diagnosis should be considered in future pregnancies. Further, even when parental karyotypes are normal, prenatal diagnosis should be offered to couples who have had two or more fetal losses due to their increased risk of having a fetus with a chromosome abnormality.     

Investigating 22q11.2 Deletion and Other Chromosomal Aberrations in Fetuses With Heart Defects Detected by Prenatal Echocardiography

Congenital heart disease (CHD) is the most common birth defect and the leading cause of mortality in the first year of life. In fetuses with a heart defect, chromosomal abnormalities are very frequent. Besides aneuploidy, 22q11.2 deletion is one of the most recognizable chromosomal abnormalities causing CHD. The frequency of this abnormality varies in nonselected populations. This study aimed to investigate the incidence of the 22q11.2 deletion and other chromosomal alterations in a Brazilian sample of fetuses with structural cardiac anomalies detected by fetal echocardiography. In a prospective study, 68 fetuses with a heart defect were evaluated. Prenatal detection of cardiac abnormalities led to identification of aneuploidy or structural chromosomal anomaly in 35.3% of these cases. None of the fetuses with apparently normal karyotypes had a 22q11.2 deletion. The heart defects most frequently associated with chromosomal abnormalities were atrioventricular septal defect (AVSD), ventricular septal defect (VSD), and tetralogy of Fallot. Autosomal trisomies 18 and 21 were the most common chromosomal abnormalities. The study results support the strong association of chromosome alterations and cardiac malformation, especially in AVSD and VSD, for which a chromosome investigation is indicated. In fetuses with an isolated conotruncal cardiopathy, fluorescence in situ hybridization (FISH) to investigate a 22q11.2 deletion is not indicated.