Prenatal detection and outcome of congenital diaphragmatic hernia (CDH) associated with deletion of chromosome 15q26: two patients and review of the literature

Congenital diaphragmatic hernia (CDH) is a severe birth defect characterized by a defect in the diaphragm with pulmonary hypoplasia and postnatal pulmonary hypertension. Approximately 50% of CDH cases are associated with other non-pulmonary congenital anomalies (so called non-isolated CDH) and in 5-10% of cases there is a chromosomal etiology. The majority of CDH cases are detected prenatally. In some cases prenatal chromosome analysis reveals a causative chromosomal anomaly, most often aneuploidy. Deletion of 15q26 is the most frequently described structural chromosomal aberration in patients with non-isolated CDH. In this paper we report on two patients with a deletion of 15q26 and phenotypes similar to other patients with CDH caused by 15q26 deletions. This phenotype consists of intra-uterine growth retardation, left-sided CDH, cardiac anomalies and characteristic facial features, similar to those seen in Fryns syndrome. We propose that when this combination of birth defects is identified, either pre- or postnatally, further investigations to confirm or exclude a deletion of 15q26 are indicated, since the diagnosis of this deletion will have major consequences for the prognosis and, therefore, can affect decision making.     

Descriptive epidemiology of Cornelia de Lange syndrome in Europe

Cornelia de Lange syndrome (CdLS) is a multiple congenital anomaly/mental retardation syndrome consisting of characteristic dysmorphic features, microcephaly, hypertrichosis, upper limb defects, growth retardation, developmental delay, and a variety of associated malformations. We present a population-based epidemiological study of the classical form of CdLS. The data were extracted from the database of European Surveillance of Congenital Anomalies (EUROCAT) database, a European network of birth defect registries which follow a standard methodology. Based on 23 years of epidemiologic monitoring (8,558,346 births in the 1980-2002 period), we found the prevalence of the classical form of CdLS to be 1.24/100,000 births or 1:81,000 births and estimated the overall CdLS prevalence at 1.6-2.2/100,000. Live born children accounted for 91.5% (97/106) of cases, fetal deaths 2.8% (3/106), and terminations of pregnancy following prenatal diagnosis 5.7% (6/106). The most frequent associated congenital malformations were limb defects (73.1%), congenital heart defects (45.6%), central nervous system malformations (40.2%), and cleft palate (21.7%). In the last 11 years, as much as 68% of cases with major malformations were not detected by routine prenatal US. Live born infants with CdLS have a high first week survival (91.4%). All patients were sporadic. Maternal and paternal age did not seem to be risk factors for CdLS. Almost 70% of patients, born after the 37th week of gestation, weighed 相似文献   

Congenital diaphragmatic defects and associated syndromes,malformations, and chromosome anomalies: A retrospective study of 60 patients and literature review

Congenital diaphragmatic defects (CDDs) may occur in malformation syndromes of varied causes. Syndromic cases of CDDs due to chromosomal defects, autosomal recessive, autosomal dominant, or X-linked inheritance have been described. In order to determine the frequency and nature of syndromes, malformations, and chromosome abnormalities associated with CDDs, we reviewed the records of all patients with CDDs evaluated over a 4-year period. During the 4-year interval, a total of 60 patients was evaluated. Of these, 29 had a therapeutic or spontaneous abortion, and 31 received postnatal care. On prenatal ultrasonography, 20 of 60 (33%) of patients with CDDs had additional anomalies. Additional anomalies, besides CDDs, were present in 15 of 31 (48%) of liveborn patients on newborn evaluation. In total, 16 patients with multiple anomalies were evaluated. Of these, 12 of 16 (75%) had additional abnormalities detected by prenatal ultrasonography. The 4 of 16 (25%) without additional anomalies on prenatal sonography had multiple anomalies found neonatally, lethal multiple pterygium syndrome being diagnosed in one case. Prenatal chromosome analysis was performed in 7 of 16 patients, and all had postnatal karyotypes. All initial karyotypes were normal. Tetrasomy 12p was documented on postnatal fibroblast analysis in one case who had percutaneous umbilical blood sampling (PUBS). Syndromes diagnosed postnatally in 7 of 16 patients (44%) include: Fryns syndrome (2), Simpson-Golabi-Behmel syndrome (2), tetrasomy 12p (1), Brachmann-de Lange syndrome (1), and lethal multiple pterygium syndrome (1). We were unable to make a specific diagnosis in 9 of 16 patients (56%) with multiple malformations. In patients with CDDs, a normal prenatal karyotype, especially if obtained by PUBS, and absence of other detected abnormalities by fetal ultrasonography, do not exclude the presence of other major anomalies, including chromosome abnormalities and severe multiple malformation syndromes. Am. J. Med. Genet. 79:215–225, 1998. © 1998 Wiley-Liss, Inc.     

Congenital clubfoot in Europe: A population‐based study

We aimed to assess prevalence, birth outcome, associated anomalies and prenatal diagnosis of congenital clubfoot in Europe using data from the EUROCAT network, and to validate the recording of congenital clubfoot as a major congenital anomaly by EUROCAT registries. Cases of congenital clubfoot were included from 18 EUROCAT registries covering more than 4.8 million births in 1995–2011. Cases without chromosomal anomalies born during 2005–2009, were randomly selected for validation using a questionnaire on diagnostic details and treatment. There was 5,458 congenital clubfoot cases of which 5,056 (93%) were liveborn infants. Total prevalence of congenital clubfoot was 1.13 per 1,000 births (95% CI 1.10–1.16). Prevalence of congenital clubfoot without chromosomal anomaly was 1.08 per 1,000 births (95% CI 1.05–1.11) and prevalence of isolated congenital clubfoot was 0.92 per 1,000 births (95% CI 0.90–0.95), both with decreasing trends over time and large variations in prevalence by registry. The majority of cases were isolated congenital clubfoot (82%) and 11% had associated major congenital anomalies. Prenatal detection rate of isolated congenital clubfoot was 22% and increased over time. Among 301 validated congenital clubfoot cases, diagnosis was confirmed for 286 (95%). In conclusion, this large population‐based study found a decreasing trend of congenital clubfoot in Europe after 1999–2002, an increasing prenatal detection rate, and a high standard of coding of congenital clubfoot in EUROCAT.     

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.     

Comparison of chromosome analysis and chromosomal microarray analysis: what is the value of chromosome analysis in today’s genomic array era?

PurposeChromosomal microarray analysis enables the detection of microdeletions/duplications and has become the standard in clinical diagnostic testing for individuals with congenital anomalies and developmental disabilities. In the era of genomic arrays, the value of traditional chromosome analysis needs to be reassessed.MethodsWe studied 3,710 unrelated patients by chromosomal microarray analysis and chromosome analysis simultaneously and compared the results.ResultsWe found that chromosomal microarray analysis detected the chromosomal imbalances that were identified by chromosome analysis with the exception of six cases (0.16%) that had mosaic abnormalities. Of note, one case showed mosaicism for two abnormal cell lines, resulting in a balanced net effect and a normal chromosomal microarray analysis. Further structural abnormalities such as unbalanced translocations, rings, and complex rearrangements were subsequently clarified by chromosome analysis in 18% of the cases with abnormal chromosomal microarray analysis results. Apparently balanced rearrangements were detected by chromosome analysis in 30 cases (0.8%).ConclusionOur data demonstrate that although chromosomal microarray analysis should be the first-tier test for clinical diagnosis of chromosome abnormalities, chromosome analysis remains valuable in the detection of mosaicism and delineation of chromosomal structural rearrangements.ConclusionGenet Med 2013:15(6):450–457     

Role of multiplex FISH in identifying chromosome involvement in myelodysplastic syndromes and acute myeloid leukemias with complex karyotypes: a report on 28 cases

Chromosomal abnormalities are found by conventional cytogenetic (CC) analysis in about 50% of myelodysplastic syndromes (MDS) and 70% of acute myeloid leukemias (AML). When cytogenetic abnormalities are complex, multiplex fluorescence in situ hybridization (M-FISH) can help clarify complex chromosomal abnormalities and identify rearrangements with prognostic value or cryptic translocations, which could be preliminary steps in identifying new genes. We studied by M-FISH 28 cases of MDS and AML with complex chromosomal abnormalities, 10 of them were therapy-related. M-FISH allowed the characterization of unidentified chromosomal material in 26 cases (93%). One or several unbalanced rearrangements were observed in 27 cases (96%), generally interpreted as deletions or additional material by CC. Among those translocations, 4 involved 3 chromosomes. Eighteen cryptic translocations undetected by CC were found in 13 cases. By FISH analysis using locus specific probes, TP53 deletion, additional copies of MLL, and additional copies or deletions of RUNX1/AML1 were observed in 16, 4, and 3 cases, respectively. Thus, M-FISH is an important tool to characterize complex chromosomal abnormalities which identified unbalanced and cryptic translocations in 96% and 46% of the cases studied, respectively. Complementary FISH helped us identify involvement of TP53, MLL, and RUNX1/AML1 genes in 82% of cases, confirming their probable role in leukemogenesis.     

Frequencies of fetal chromosomal abnormalities at prenatal diagnosis: 10 years experiences in a single institution.

We present frequencies of fetal chromosomal abnormalities in 4,907 prenatal cytogenetic examinations at Samsung Cheil Hospital from 1988 to 1997 for 10 yr duration. Prenatal karyotypes were undertaken in 3,913 amniotic fluid samples, 800 chorionic villi samples, and 194 percutaneous umbilical blood samples. The frequency of fetal abnormal karyotypes was 3.1% (150 cases). Numerical chromosome abnormalities were 87 cases (1.8%) and structural aberrations of chromosomes were 63 cases (1.3%). In the numerical chromosomal abnormalities, the frequency of trisomy 21 was by far the highest (36 cases), followed by trisomy 18 in 22 cases and sex chromosome aneuploidies in 19 cases. In the structural chromosomal aberrations, 5 cases had the inversions in chromosome 2, 7, 17, and Y. Chromosomal deletions in 6 cases and additions in 4 cases were analysed. Of the remaining 47 translocation in abnormal fetuses, reciprocal translocation was in 26 cases and Robertsonian translocation in 21 cases. Among them, 41 cases were balanced translocation and 6 were unbalanced. Thirty five cases of translocation were inherited from one of the parents. Four had de novo chromosome rearrangements, and 8 cases were unknown.     

Intrauterine phenotype features of fetuses with Williams–Beuren syndrome and literature review

Williams–Beuren syndrome (WBS) is a well-defined multisystem chromosomal disorder that is caused by a chromosome 7q11.23 region heterozygous deletion. We explored prenatal diagnosis of WBS by ultrasound as well as multiple genetic methods to characterize the structural variants of WBS prenatally. Expanded noninvasive prenatal testing (NIPT-plus) was elected as a regular prenatal advanced screen for risk assessments of fetal chromosomal aneuploidy and genome-wide microdeletion/microduplication syndromes at the first trimester. At the second and three trimester, seven prenatal cases of WBS were evaluated for the indication of the invasive testing, the ultrasound features, cytogenetic, single-nucleotide polymorphism array (SNP array), and fluorescent quantitative PCR (QF-PCR) results. The NIPT-plus results for seven fetuses were low risk. All cryptic aberrations were detected by the SNP array as karyotyping analyses were negative. Subsequently, QF-PCR further confirmed the seven deletions. Combining our cases with 10 prenatal cases from the literature, the most common sonographic features were intrauterine growth retardation (82.35%, 14/17) and congenital cardiovascular abnormalities (58.82%, 10/17). The manifestations of cardiovascular defects mainly involve supravalvar aortic stenosis (40%, 4/10), ventricular septal defect (30%, 3/10), aortic coarctation (20%, 2/10), and peripheral pulmonary artery stenosis (20%, 2/10). To the best of our knowledge, this is the first largest prenatal study of WBS cases with detailed molecular analysis. Aortic coarctation combined with persistent left superior vena cava and right aortic arch cardiovascular defects were first reported in prenatal WBS cases by our study.     

Identification of 14 rare marker chromosomes and derivatives by spectral karyotyping in prenatal and postnatal diagnosis

Extra structurally abnormal chromosomes (ESACs) and cryptic rearrangements are often associated with mental retardation and phenotypic abnormalities. In some cases their characterisation, using standard cytogenetic techniques and fluorescence in situ hybridization (FISH), is difficult and time consuming, where a fast and accurate identification is essential, especially when such chromosomal aberrations are found in prenatal diagnosis. A recent molecular technique, spectral karyotyping (SKY), based on the spectral signature of 24 chromosome-specific painting probes labelled with different combinations of five fluorochromes, allows the simultaneous visualisation of all human chromosomes in different colours. We used SKY analysis on 14 cases with rare ESACs or cryptic unbalanced rearrangements found at pre- or postnatal diagnosis. SKY analysis permitted the classification of chromosome rearrangements in all 14 cases analysed in combination with FISH analysis.     

Cryptic deletions are a common finding in "balanced" reciprocal and complex chromosome rearrangements: a study of 59 patients

Using array comparative genome hybridisation (CGH) 41 de novo reciprocal translocations and 18 de novo complex chromosome rearrangements (CCRs) were screened. All cases had been interpreted as "balanced" by conventional cytogenetics. In all, 27 cases of reciprocal translocations were detected in patients with an abnormal phenotype, and after array CGH analysis, 11 were found to be unbalanced. Thus 40% (11 of 27) of patients with a "chromosomal phenotype" and an apparently balanced translocation were in fact unbalanced, and 18% (5 of 27) of the reciprocal translocations were instead complex rearrangements with >3 breakpoints. Fourteen fetuses with de novo, apparently balanced translocations, all but two with normal ultrasound findings, were also analysed and all were found to be normal using array CGH. Thirteen CCRs were detected in patients with abnormal phenotypes, two in women who had experienced repeated spontaneous abortions and three in fetuses. Sixteen patients were found to have unbalanced mutations, with up to 4 deletions. These results suggest that genome-wide array CGH may be advisable in all carriers of "balanced" CCRs. The parental origin of the deletions was investigated in 5 reciprocal translocations and 11 CCRs; all were found to be paternal. Using customized platforms in seven cases of CCRs, the deletion breakpoints were narrowed down to regions of a few hundred base pairs in length. No susceptibility motifs were associated with the imbalances. These results show that the phenotypic abnormalities of apparently balanced de novo CCRs are mainly due to cryptic deletions and that spermatogenesis is more prone to generate multiple chaotic chromosome imbalances and reciprocal translocations than oogenesis.     

Associated malformations and chromosomal anomalies in 42 cases of prenatally diagnosed diaphragmatic hernia.

We present a retrospective study of the frequency and type of associated malformations and chromosomal anomalies in 42 consecutive cases of congenital diaphragmatic hernia (CDH) diagnosed in utero during the period from 1985 to 1999. In 26% (11/42) of the cases, associated malformations were detected. Chromosomal anomalies were present in 9.5% (4/42). In this group of 15 cases (15/42 = 36%) with associated malformations or chromosomal anomalies, all cases, except one, had prenatal sonographic evidence of additional problems. The survival rate of fetuses with CDH and associated malformations or chromosomal anomalies was poor (1/15). Therefore, the overall survival rate of in utero-diagnosed CDH was only 31% (13/42), while isolated left CDH had a survival rate of 52% (12/23). The in utero diagnosis of CDH implies a detailed echographic examination to exclude additional anomalies. The risk for a syndromal or chromosomal malformation becomes small when no additional anomalies are seen on ultrasound.     

Associated anomalies in cases with congenital clubfoot

Congenital clubfoot CTEV is a common congenital anomaly, its etiology is unclear and its pathogenesis is controversial. Cases with CTEV often have other non‐CTEV associated congenital anomalies. The purpose of this study was to assess the prevalence and the types of these associated anomalies in a defined population. The associated anomalies in cases with CTEV were collected in all livebirths, stillbirths, and terminations of pregnancy during 29 years in 387,067 consecutive births in the area covered by our population‐based registry of congenital malformations. Of the 504 cases with CTEV, representing a prevalence of 13.02 per 10,000, 107 (21.2%) had associated anomalies. There were 31 (6.1%) cases with chromosomal abnormalities, and 21 (4.2%) non‐chromosomal recognized dysmorphic conditions including syndromes: 6 arthrogryposis multiplex congenita, 2 22q11.2 microdeletion, and one fetal alcohol syndrome. Fifty‐five (10.9%) of the cases had nonsyndromic multiple congenital anomalies (MCA). Anomalies in the cardiovascular, the central nervous, the urinary, the orofacial, and the musculoskeletal systems were the most common other anomalies in the cases with MCA. The anomalies associated with CTEV could be classified into a recognizable malformation syndrome in 52 of the 107 cases (48.6%) with associated anomalies. This study included special strengths: it is population‐based, each affected child was examined by a geneticist, all elective terminations were ascertained, and the surveillance for anomalies was continued until 2 years of age. In conclusion the overall prevalence of associated anomalies, one of five cases, emphasizes the need for a screening for other anomalies in cases with CTEV.     

Associated malformations and chromosomal anomalies in 42 cases of prenatally diagnosed diaphragmatic hernia

We present a retrospective study of the frequency and type of associated malformations and chromosomal anomalies in 42 consecutive cases of congenital diaphragmatic hernia (CDH) diagnosed in utero during the period from 1985 to 1999. In 26% (11/42) of the cases, associated malformations were detected. Chromosomal anomalies were present in 9.5% (4/42). In this group of 15 cases (15/42 = 36%) with associated malformations or chromosomal anomalies, all cases, except one, had prenatal sonographic evidence of additional problems. The survival rate of fetuses with CDH and associated malformations or chromosomal anomalies was poor (1/15). Therefore, the overall survival rate of in utero‐diagnosed CDH was only 31% (13/42), while isolated left CDH had a survival rate of 52% (12/23). The in utero diagnosis of CDH implies a detailed echographic examination to exclude additional anomalies. The risk for a syndromal or chromosomal malformation becomes small when no additional anomalies are seen on ultrasound.     

Prader-Willi syndrome resulting from an unbalanced translocation: characterization by array comparative genomic hybridization

Prader-Willi syndrome (PWS) is caused by lack of expression of paternally inherited genes on chromosome 15q11-->15q13. Most cases result from microdeletions in proximal chromosome 15q. The remainder results from maternal uniparental disomy of chromosome 15, imprinting center defects, and rarely from balanced or unbalanced chromosome rearrangements involving chromosome 15. We report a patient with multiple congenital anomalies, including craniofacial dysmorphology, microcephaly, bilateral cryptorchidism, and developmental delay. Cytogenetic analysis showed a de novo 45,XY,der(5)t(5;15)(p15.2;q13), -15 karyotype. In effect, the proband had monosomies of 5p15.2-->pter and 15pter-->15q13. Methylation polymerase chain reaction analysis of the promoter region of the SNRPN gene showed only the maternal allele, consistent with the PWS phenotype. The proband's expanded phenotype was similar to other patients who have PWS as a result of unbalanced translocations and likely reflects the contribution of the associated monosomy. Array comparative genomic hybridization (array CGH) confirmed deletions of both distal 5p and proximal 15q and provided more accurate information as to the size of the deletions and the molecular breakpoints. This case illustrates the utility of array CGH in characterizing complex constitutional structural chromosome abnormalities at the molecular level.     

Molecular cytogenetic pre- and postnatal diagnosis of chromosomal abnormalities

Molecular cytogenetic studies in the prenatal and postnatal identification of chromosomal anomalies in children with mental retardation and congenital developmental malformations are discussed. Molecular cytogenetic techniques, such as fluorescence in situ hybridization (FISH) are employed after the use of classic cytogenetic studies. FISH diagnosis is recommended to apply in the cases when classic cytogenetic methods are not beneficial: post- and prenatal autosomal trisomies; gonosomal aneuploidies, including mosaic forms; marker chromosomes; structural chromosomal anomalies, including fragile X syndrome. The authors' experience showed that (1) FISH should be utilized only as an adjunctive test for classical cytogenetic studies when banding techniques are ineffective; (2) FISH confirms a cytogenetic diagnosis; (3) multicolored probe detection gives an additional possibility in the FISH analysis. The findings demonstrate that molecular cytogenetic methods provide a rapid accurate approach to investigating and diagnosing chromosomal anomalies. Molecular cytogenetic diagnosis allows a more correct correlation of chromosomal abnormalities to be shown with a clinical picture and assists in identifying new chromosomal syndromes in children with undifferentiated forms of mental retardation and congenital malformations.     

Genetic diagnoses and associated anomalies in fetuses prenatally diagnosed with esophageal atresia

Esophageal atresia (EA) is a congenital anomaly occurring in 2.3 per 10,000 live births. Due to advances in prenatal imaging, EA is more readily diagnosed, but data on the associated genetic diagnoses, other anomalies, and postnatal outcome for fetuses diagnosed prenatally with EA are scarce. We collected data from two academic medical centers (n = 61). Our data included fetuses with suspected EA on prenatal imaging that was confirmed postnatally and had at least one genetic test. In our cohort of 61 cases, 29 (49%) were born prematurely and 19% of those born alive died in the first 9 years of life. The most commonly associated birth defects were cardiac anomalies (67%) and spine anomalies (50%). A diagnosis was made in 61% of the cases; the most common diagnoses were vertebral defects, anal atresia, cardiac anomalies, tracheoesophageal fistula with esophageal atresia, radial or renal dysplasia, and limb anomalies association (43%, although 12% met only 2 of the criteria), trisomy 21 (5%), and CHARGE syndrome (5%). Our findings suggest that most fetuses with prenatally diagnosed EA have one or more additional major anomaly that warrants a more comprehensive clinical genetics evaluation. Fetuses diagnosed prenatally appear to represent a cohort with a worse outcome.     

2371例孕妇产前诊断的指证及其结果分析

目的分析产前诊断指证与胎儿染色体检测结果的关系。方法 2371例有产前诊断指证的孕妇,进行羊膜腔穿刺或脐静脉穿刺术,取羊水细胞或脐血细胞培养,作胎儿染色体核型分析。结果 2371例孕妇共检出胎儿染色体异常60例,染色体异常率为2.53%,显著高于一般人群的异常率（P〈0.01）。其中孕母血清唐氏筛查阳性组和高龄孕妇组的异常率分别为1.63%（13/794）、2.32%（15/646）,产前胎儿超声异常标记组胎儿染色体异常率16.12%（15/93）,夫妇一方为染色体平衡易位携带者组的胎儿染色体异常率达71.4%（5/7）,21-三体儿检出25例,占异常率的41.67%（25/60）,其中一例连续两次诊断出21-三体儿。结论出现胎儿染色体异常率最高的指证,依次为平衡易位携带、产前超声发现胎儿异常标记、高龄孕妇、孕母血清唐氏筛查阳性。掌握好产前诊断指证,可更有价值地控制和减少出生缺陷的发生。     

Prenatal testing in ICSI pregnancies: incidence of chromosomal anomalies in 1586 karyotypes and relation to sperm parameters

BACKGROUND: Prenatal testing was offered in all pregnancies obtained after ICSI with ejaculated or non-ejaculated sperm as part of the evaluation of the safety of ICSI. METHODS: Between 1990 and 2001, a chorionic villus sampling (CVS) or amniocentesis was offered for multiple or singleton pregnancies respectively during a genetic counselling session for all couples applying for ICSI. ICSI was carried out using ejaculated, epididymal or testicular sperm. RESULTS: In total, 1586 ICSI fetuses obtained after fresh embryo transfer were tested by CVS (n = 698) or by amniocentesis (n = 888). Abnormal fetal karyotypes were found in 47 samples [3.0%; 95% confidence interval (CI) 2.2-3.9%]; 25 anomalies (1.6%; 95% CI 1.0-2.3%) were de novo. These were 10 sex chromosomal anomalies and 15 autosomal anomalies [either numerical (n = 8) or structural (n = 7)], and 22 inherited abnormalities (1.4%; 95% CI 0.9-2.1%) (21 balanced, one unbalanced). In 17/22 inherited cases the chromosomal structural defect was inherited from the father. A significantly higher percentage of 2.1% de-novo prenatal chromosomal anomalies was observed for sperm concentrations of <20x10(6) sperm per ml, as compared with 0.24% if the sperm concentration was vertical line 20x10(6) sperm per ml (Fisher's exact test, P = 0.006). No statistical difference in frequency of chromosomal anomalies was observed for lower threshold values of sperm concentration (<1x10(6), <5x10(6), <10x10(6) and <15x10(6)). A statistical difference was observed for motility criteria, but not morphology. Three chromosomal anomalies were found prenatally after use of epididymal or testicular sperm in a total of 94 samples; two (of 83 tested) were from patients with obstructive and one (of nine tested) was from a patient with non-obstructive azoospermia. CONCLUSIONS: A significantly higher rate of de-novo chromosomal anomalies (1.6 versus 0.5% in amniocentesis for a mean maternal age of 33.5 years; P < 0.007) was observed in ICSI offspring, relating mainly to a higher number of sex chromosomal anomalies and partly to a higher number of autosomal structural anomalies. This finding was related to sperm concentration and motility. The significantly higher rate of observed inherited anomalies (1.4 versus 0.3-0.4% in prenatal tests in the general population; P < 0.001) was related to a higher rate of constitutional chromosomal anomalies, mainly in the fathers. The hypothesis of a higher risk of post-zygotic events as a consequence of the ICSI procedure leading to a higher proportion of chromosomal mosaicism was not confirmed in this study. Couples should be informed of the risks of an abnormal result related to sperm quality, and of the risk linked to a prenatal procedure as well as about the relatively benign character of some chromosomal anomalies such as de-novo structural anomalies or sex chromosomal anomalies in order to be able to make a choice for prenatal testing, or not.