Fetal gastroschisis: Maternal and fetal methylation profile.

OBJECTIVE: The purpose of this study was to describe the genomic deoxyribonucleic acid (DNA) methylation profile in fetuses with gastroschisis, determine whether the profile was inherited, and investigate any possible correlations with maternal risk factors. METHOD: Genome-wide DNA methylation analysis of 96 blood samples was performed using the Illumina Human Methylation 850K BeadChip. The blood samples were collected as follows: 32 from the umbilical cord of fetuses with gastroschisis, 32 from their respective mothers, 16 from the umbilical cord of fetuses without malformation, and 16 from their respective mothers. RESULTS: The differential DNA methylation analysis showed a significant difference between the groups. The enrichment analysis resulted in 12 sites related to T-cell activation (p = 0.0128). The sites with different methylation status contained 10 genes, three of which were related to the beta-2-microglobulin gene. The methylation profile observed in the fetuses with gastroschisis was not inherited from the mothers. In addition, there was no association between maternal urinary tract infection, smoking, and alcohol use and different methylated sites. CONCLUSION: We established the methylation profile of gastroschisis fetuses, which differs from that of normal fetuses. The profile was not inherited and did not correlate with maternal risk factors.

Whole exome sequencing identifies multiple novel candidate genes in familial gastroschisis.

BACKGROUND: Genetic association studies for gastroschisis have highlighted several candidate variants. However, genetic basis in gastroschisis from noninvestigated heritable factors could provide new insights into the human biology for this birth defect. We aim to identify novel gastroschisis susceptibility variants by employing whole exome sequencing (WES) in a Mexican family with recurrence of gastroschisis. METHODS: We employed WES in two affected half-sisters with gastroschisis, mother, and father of the proband. Additionally, functional bioinformatics analysis was based on SVS-PhoRank and Ensembl-Variant Effect Predictor. The latter assessed the potentially deleterious effects (high, moderate, low, or modifier impact) from exome variants based on SIFT, PolyPhen, dbNSFP, Condel, LoFtool, MaxEntScan, and BLOSUM62 algorithms. The analysis was based on the Human Genome annotation, GRCh37/hg19. Candidate genes were prioritized and manually curated based on significant phenotypic relevance (SVS-PhoRank) and functional properties (Ensembl-Variant Effect Predictor). Functional enrichment analysis was performed using ToppGene Suite, including a manual curation of significant Gene Ontology (GO) biological processes from functional similarity analysis of candidate genes. RESULTS: No single gene-disrupting variant was identified. Instead, 428 heterozygous variations were identified for which SPATA17, PDE4DIP, CFAP65, ALPP, ZNF717, OR4C3, MAP2K3, TLR8, and UBE2NL were predicted as high impact in both cases, mother, and father of the proband. PLOD1, COL6A3, FGFRL1, HHIP, SGCD, RAPGEF1, PKD1, ZFHX3, BCAS3, EVPL, CEACAM5, and KLK14 were segregated among both cases and mother. Multiple interacting background modifiers may regulate gastroschisis susceptibility. These candidate genes highlight a role for development of blood vessel, circulatory system, muscle structure, epithelium, and epidermis, regulation of cell junction assembly, biological/cell adhesion, detection/response to endogenous stimulus, regulation of cytokine biosynthetic process, response to growth factor, postreplication repair/protein K63-linked ubiquitination, protein-containing complex assembly, and regulation of transcription DNA-templated. CONCLUSION: Considering the likely gene-disrupting prediction results and similar biological pattern of mechanisms, we propose a joint "multifactorial model" in gastroschisis pathogenesis.

A clinical-pathogenetic approach on associated anomalies and chromosomal defects supports novel candidate critical regions and genes for gastroschisis.

BACKGROUND: Gastroschisis has been assumed to have a low rate of syndromic and primary malformations. We aimed to systematically review and explore the frequency and type of malformations/chromosomal syndromes and to identify significant biological/genetic roles in gastroschisis. METHODS: Population-based, gastroschisis-associated anomalies/chromosomal defects published 1950-2018 (PubMed/MEDLINE) were independently searched by two reviewers. Associated anomalies/chromosomal defects and selected clinical characteristics were subdivided and pooled by race, system/region, isolated, and associated cases (descriptive analysis and chi-square test were performed). Critical regions/genes from representative chromosomal syndromes including an enrichment analysis using Gene Ontology Consortium/Panther Classification System databases were explored. Fisher's exact test with False Discovery Rate multiple test correction was performed. RESULTS: Sixty-eight articles and 18525 cases as a base were identified (prevalence of 17.9 and 3% for associated anomalies/chromosomal defects, respectively). There were 3596 associated anomalies, prevailing those cardiovascular (23.3%) and digestive (20.3%). Co-occurring anomalies were associated with male, female, American Indian, Caucasian, prenatally diagnosed, chromosomal defects, and mortality (P < 0.00001). Gene clusters on 21q22.11 and 21q22.3 (KRTAP), 18q21.33 (SERPINB), 18q22.1 (CDH7, CDH19), 13q12.3 (FLT1), 13q22.1 (KLF5), 13q22.3 (EDNRB), and 13q34 (COL4A1, COL4A2, F7, F10) were significantly related to biological processes: blood pressure regulation and/or vessel integrity, angiogenesis, coagulation, cell-cell and/or cell-matrix adhesion, dermis integrity, and wound healing (P < 0.05). CONCLUSIONS: Our findings suggest that gastroschisis may result from the interaction of several chromosomal regions in an additive manner as a pool of candidate genes were identified from critical regions supporting a role for vascular disruption, thrombosis, and mesodermal deficiency in the pathogenesis of gastroschisis.

Genetic variants conferring susceptibility to gastroschisis: a phenomenon restricted to the interaction with the environment?

BACKGROUND: Genes involved in gastroschisis have shown a strong interaction with environmental factors. However, less is known about its influence. We aimed to systematically review the genetic associations of gastroschisis, to summarize whether its genetic susceptibility has been restricted to the interaction with the environment, and to identify significant gaps that remain for consideration in future studies. METHODS: Genetic association studies of gastroschisis published 1980-2017 (PubMed/MEDLINE) were independently searched by two reviewers. Significant SNP-gastroschisis associations were grouped into crude and stratified risks, whereas SNPs were assessed from two or more independent studies. Frequencies, odds ratios, and 95% confidence intervals were pooled using descriptive analysis and Chi-square test accounting for heterogeneity. RESULTS: Seven eligible articles capturing associations of 14 SNPs from 10 genes for crude risk (including 10 and 4 SNPs with increased and decreased risk, respectively) and 30 SNPs from 14 genes for stratified risk in gastroschisis (including 37 and 14 SNPs with increased and decreased risk, respectively) were identified (Fisher's exact test, P = 0.438). The rs4961 (ADD1), rs5443 (GNB3), rs1042713, and rs1042714 (ADRB2) were significantly associated with gastroschisis. CONCLUSIONS: Genetic susceptibility in gastroschisis is not restricted to the interaction with the environment and should not be too narrowly focused on environmental factors. We found significant associations with four SNPs from three genes related to blood pressure regulation, which supports a significant role of vascular disruption in the pathogenesis of gastroschisis. Future studies considering gene-gene or gene-environmental interactions are warranted for better understanding the etiology of gastroschisis.

Familial occurrence of gastroschisis: a population-based overview on recurrence risk, sex-dependent influence, and geographical distribution.

PURPOSE: There is uncertainty over whether familial recurrences in gastroschisis might be higher. Moreover, scant information is available regarding its sociodemographic features. We aim to explore the recurrence risk, sex-dependent influence, and geographical distribution of familial gastroschisis. METHODS: A systematic review of the literature and data extraction from population-based studies published 1970-2017 (PubMed/MEDLINE) was independently performed by two reviewers. Familial ocurrence of gastroschisis, whereas sociodemographic features from 11 studies were pooled including 862 probands as a base. A descriptive analysis and Chi-square test were performed. RESULTS: Twenty-four probands had a positive family history of gastroschisis including 49 affected family members, for a recurrence risk of 5.7 and 3% adjusted for proband. Siblings' recurrence was 4.3%. Sex-dependent influence analysis (n = 879, from three studies) evidenced an increased susceptibility to gastroschisis in males (2.5%) compared to females (1.3%) adjusted for proband. Heterogeneity was identified by Fisher's exact test (P = 0.023). CONCLUSION: Our findings support a greater liability attributable to familial factors on gastroschisis along with significant information for family and prenatal counseling. We suggest that future studies should include for a more accurate account for both familial and environmental confounding factors to uncover relatives and environmental exposures that more limited family histories may have missed.

Evaluation of familial factors in a Mexican population-based setting with gastroschisis: Further evidence for an underlying genetic susceptibility.

PURPOSE: To evaluate the occurrence of gastroschisis attributable to familial factors in a Mexican population-based setting. METHODS: A descriptive study was performed among gastroschisis cases born from 2010 through 2016 at Tijuana General Hospital (Baja California, Mexico) to generate multigenerational pedigrees. RESULTS: There were 87 gastroschisis cases from 57,217 live births. Six probands (6.9%) had another affected family member. Two half-siblings, a set of monozygotic twins, a mother-and-daughter occurrence, a distant paternal cousin and a distant maternal uncle were identified. Sibling recurrence was 5.5%. From 174 males and 153 females studied (n=327, involving 180 nuclear families), sex-dependent influence analysis evidenced an increased susceptibility to gastroschisis in males (3.2%) compared to females (1.8%) with an overall of 2.5% adjusted for proband. CONCLUSIONS: Our results provide a greater liability attributable to familial factors on gastroschisis. In spite of the predominant sporadic occurrence, underlying genetic susceptibility and environmental influences point to a complex interplay between genes and environmental factors in gastroschisis. LEVEL OF EVIDENCE: Level IV.

Gene variants as risk factors for gastroschisis.

In a population-based case-control study in California of 228 infants, we investigated 75 genetic variants in 20 genes and risk of gastroschisis with regard to maternal age, race/ethnicity, vitamin use, and smoking exposure. We hypothesized that genes related to vascular compromise may interact with environmental factors to affect the risk of gastroschisis. Haplotypes were constructed for 75 gene variants using the HaploView program. Risk for gastroschisis associated with each gene variant was calculated for both the homozygotes and the heterozygotes, with the homozygous wildtypes as the referent. Risks were estimated as odds ratios (ORs) with 95% confidence intervals (CIs) by logistic regression. We found 11 gene variants with increased risk and four variants with decreased risk of gastroschisis for heterozygous (ORh ) or homozygous variants (ORv ) genotypes. These included NOS3 (rs1036145) ORh = 0.4 (95% CI: 0.2-0.7); NOS3 (rs10277237) ORv = 2.7 (95% CI: 1.3-6.0); ADD1 (rs12503220) ORh = 2.9 (95% CI: 1.6-5.4), GNB3 (rs5443) ORh = 0.2 (95% CI: 0.1-0.5), ORv = 0.4 (95% CI: 0.2-0.9); ICAM1 (rs281428) ORv = 6.9 (95% CI: 2.1-22.9), ICAM1 (rs3093030) ORv = 2.6 (95% CI: 1.2-5.6); ICAM4 (rs281438) ORv = 4.9 (95% CI: 1.4-16.6), ICAM5 (rs281417) ORh = 2.1 (95% CI: 1.1-4.1), ORv = 4.8 (95% CI: 1.7-13.6); ICAM5 (rs281440) ORh = 23.7 (95% CI: 5.5-102.5), ORv = 20.6 (95% CI: 3.4-124.3); ICAM5 (rs2075741) ORv = 2.2 (95% CI: 1.1-4.4); NAT1 ORv = 0.3 (95% CI: 0.1-0.9). There were additional associations between several gene variants and gastroschisis among women aged 20-24 and among mothers with and without vitamin use. NOS3, ADD1, ICAM1, ICAM4, and ICAM5 warrant further investigation in additional populations and with the interaction of additional environmental exposures. © 2016 Wiley Periodicals, Inc.

Effects of MTHFR c.677C>T, F2 c.20210G>A and F5 Leiden Polymorphisms in Gastroschisis.

BACKGROUND: Gastroschisis is a developmental disorder involving the extrusion of fetal intestines through a defect in the abdominal wall. The mechanism is presumed to be a dual vascular/thrombotic pathogenesis, where normal right umbilical vein involution forms a possible site for thrombosis adjacent to the umbilical ring. PURPOSE: The aim of this study was to demonstrate that the 3 common prothrombotic polymorphisms, MTHFR c.677C>T, F2 c.20210G>A, and F5 Leiden, were elevated in frequency in Indonesian gastroschisis patients. MATERIAL AND METHODS: Three genetic markers were investigated in 46 patients with gastroschisis and 89 ethnicity-matched controls for association studies using polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) or TaqMan Genotyping Assays on genomic DNA. RESULTS: MTHFR c.677C>T showed a significant association with gastroschisis (OR = 2.1, 95% CI = 1.13-3.86; p = .018) but no affected infants had risk alleles for either F2 c.20210G>A or F5 Leiden. Further, the frequency of MTHFR risk allele (T) in patients with maternal age <25 years is marginally significant higher than those in cases with maternal age ≥25 years (p = .069) with an OR of 2.7 (95% CI = 0.90-8.07). CONCLUSIONS: MTHFR is a common susceptibility factor for gastroschisis in Indonesia. The increased gastroschisis risk in offspring of younger maternal age suggests the thrombotic pathogenesis model. A founder effect is the most likely explanation for the rarity of the F2 and F5 Leiden polymorphisms in Indonesian population.

Maternal smoking, xenobiotic metabolizing enzyme gene variants, and gastroschisis risk.

Maternal smoking during pregnancy is one proposed risk factor for gastroschisis, but reported associations have been modest, suggesting that differences in genetic susceptibility might play a role. We included 108 non-Hispanic white and 62 Hispanic families who had infants with gastroschisis, and 1,147 non-Hispanic white and 337 Hispanic families who had liveborn infants with no major structural birth defects (controls) in these analyses. DNA was extracted from buccal cells collected from infants and mothers, and information on periconceptional smoking history was obtained from maternal interviews, as part of the National Birth Defects Prevention Study. We analyzed five polymorphisms in three genes that code for enzymes involved in metabolism of some cigarette smoke constituents (CYP1A1, CYP1A2, and NAT2). Logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) independently for maternal smoking and maternal and infant gene variants, and to assess joint associations of maternal smoking and maternal or infant gene variants with gastroschisis. In analyses adjusted for maternal age at delivery and stratified by maternal race-ethnicity, we identified three suggestive associations among 30 potential associations with sufficient numbers to calculate ORs: CYP1A1*2A for non-Hispanic white mothers who smoked periconceptionally (aOR = 0.38, 95% CI 0.15-0.98), and NAT2*6 for Hispanic non-smoking mothers (aOR = 2.17, 95% CI 1.12-4.19) and their infants (aOR = 2.11, 95% CI 1.00-4.48). This analysis does not support the occurrence of effect modification between periconceptional maternal smoking and most of the xenobiotic metabolizing enzyme gene variants assessed.

A vascular and thrombotic model of gastroschisis.

A binary vascular/thrombotic pathogenesis for gastroschisis, a form of congenital bowel herniation, is proposed, where normal right umbilical vein involution creates a possible site for thrombosis adjacent to the umbilical ring. If thrombosis occurs, it weakens the area, explaining overwhelmingly right-sided lesions. The model arises from the existence of two groups of risk factors with different maternal age associations. Older mothers show a greater association with vascular factors (although this may actually represent a lack of any significant maternal age effect), consistent with associations of gastroschisis with congenital heart lesions and with amyoplasia. Alternatively, other predispositions, and especially decreased maternal age, the greatest known risk factor, associate with factors raising maternal estrogen, with evidence that estrogen in turn acts here as a predisposition to thrombosis. Absorption of thrombotic by-products from the amniotic fluid can explain the unusual amniocyte inclusions that are common with gastroschisis, while a role for estrogens suggests a connection between rising gastroschisis prevalence and increasing environmental contamination with estrogen disruptors. This model explains a variety of structural and epidemiological findings, and suggests that stratification of data based on binary effects may clarify associated risks and mechanisms. The model also shows that what is often referred to as vascular disruption may actually reflect alternative or additional factors instead, including thrombosis as a primary mechanism.

Fetal abdominal wall defects.

The most common fetal abdominal wall defects are gastroschisis and omphalocele, both with a prevalence of about three in 10,000 births. Prenatal ultrasound has a high sensitivity for these abnormalities already at the time of the first-trimester nuchal scan. Major unrelated defects are associated with gastroschisis in about 10% of cases, whereas omphalocele is associated with chromosomal or genetic abnormalities in a much higher proportion of cases. Challenges in management of gastroschisis are related to the prevention of late intrauterine death, and the prediction and treatment of complex forms. With omphalocele, the main difficulty is the exclusion of associated conditions, not all diagnosed prenatally. An outline of the postnatal treatment of abdominal wall defects is given. Other rarer forms of abdominal wall defects are pentalogy of Cantrell, omphalocele, bladder exstrophy, imperforate anus, spina bifida complex, prune-belly syndrome, body stalk anomaly, and bladder and cloacal exstrophy; they deserve multidisciplinary counselling and management.

Novel exomphalos genetic mouse model: the importance of accurate phenotypic classification.

BACKGROUND: Rodent models of abdominal wall defects (AWD) may provide insight into the pathophysiology of these conditions including gut dysfunction in gastroschisis, or pulmonary hypoplasia in exomphalos. Previously, a Scribble mutant mouse model (circletail) was reported to exhibit gastroschisis. We further characterise this AWD in Scribble knockout mice. METHOD: Homozygous Scrib knockout mice were obtained from heterozygote matings. Fetuses were collected at E17.5-18.5 with intact amniotic membranes. Three mutants and two control fetuses were imaged by in amnio micro-MRI. Remaining fetuses were dissected, photographed and gut length/weight measured. Ileal specimens were stained for interstitial cells of Cajal (ICC), imaged using confocal microscopy and ICC quantified. RESULTS: 127 fetuses were collected, 15 (12%) exhibited AWD. Microdissection revealed 3 mutants had characteristic exomphalos phenotype with membrane-covered gut/liver herniation into the umbilical cord. A further 12 exhibited extensive AWD, with eviscerated abdominal organs and thin covering membrane (intact or ruptured). Micro-MRI confirmed these phenotypes. Gut was shorter and heavier in AWD group compared to controls but morphology/number of ICC was not different. DISCUSSION: The Scribble knockout fetus exhibits exomphalos (intact and ruptured), in contrast to the original published phenotype of gastroschisis. Detailed dissection of fetuses is essential ensuring accurate phenotyping and result reporting.

Clinical risk factors for gastroschisis and omphalocele in humans: a review of the literature.

Gastroschisis and omphalocele are usually considered together since they are both congenital abdominal wall defects, and yet their anatomy, embryogenesis, and clinical presentation and problems are quite different. In addition, it appears that the risk factors for their occurrence differ. Etiologic factors contributing to the development of these defects are unknown. To investigate this we have reviewed reports of risk factors for each anomaly and report them here. We conducted a literature search using PubMed (http://www.ncbi.nlm.nih.gov/pubmed/) for risk factors implicated in the development of gastroschisis and omphalocele. The data reviewed here from clinical studies in the literature, closely parallels the data in animal studies which we reported earlier. There is little evidence for a genetic cause in the development of gastroschisis and much evidence supporting the possibility that environmental teratogens are important contributors to the development of this defect. On the other hand, in the case of omphalocele, there was little evidence for environmental factors and substantial data indicating that genetic or familial factors may play an important role.

A cluster study of gastroschisis: single center experience.

BACKGROUND AND METHODS: A cluster of 10 neonates admitted with a diagnosis of gastroschisis at birth to the Neonatal Intensive Care Unit (NICU) at the University of Kentucky Medical Center in the year 1996, prompted us to perform a retrospective analysis to determine environmental or genetic causes. RESULTS: A total of 36 neonates with gastroschisis were admitted during the period 1/1992 to 12/1996, and the maternal and patient demographics were evaluated by chart review. The mean maternal age was 21.5 years (14-35 years) of which 42% were teenagers, 66% were primiparous, 42% were smokers, 6% had a history of illicit drug use, and 72% had a history of taking prenatal vitamins. Mean birth weight was 2438g (990-3700g) with 54% being preterm with a mean gestational age of 36 wks (29-40 wks). Family history was negative and chromosomes were normal in patients in whom a karyotype was performed (25%). There was no recurring environmental or drug exposure in the study group. The mothers were from 24 different counties of Kentucky. The 36 cases were not uniformly distributed over the five-year period (chi square statistic = 46.8, degrees of freedom = 4, p < 0.0001). However, there was no evidence that the cases clustered in any 1 year (p = 0.99 for Ederer-Myers-Mantel test). CONCLUSIONS: This is one of the few cluster studies of babies born with gastroschisis. Many of the mothers were teenagers, primiparous, and had an increased frequency of smoking. There was no evidence of temporal or spatial clustering in the gastroschisis cases. We conclude that the cluster of gastroschisis cases in our study occurred as a matter of chance.

Gastroschisis: a gene-environment model involving the VEGF-NOS3 pathway.

Gastroschisis is a severe major malformation in which an infant is delivered with a portion of intestines and possible other abdominal organs extruding through a defect in the abdominal wall, usually to the right of the umbilical cord. Etiologies of gastroschisis are largely unknown, and even its pathogenesis is poorly understood. Several recent epidemiological studies have identified interactions between maternal smoking during pregnancy, genetic variants of endothelial nitric oxide synthase, and risk for gastroschisis. We present a brief review of the endothelial nitric oxide synthase pathway and its relationship to vasculogenesis, suggesting that disruption of this pathway by environmental exposures or by genetic variation may represent one pathogenetic model for gastroschisis.

Outcome of antenatally diagnosed abdominal wall defects.

OBJECTIVE: To examine the natural history and detailed outcome of antenatally diagnosed abdominal wall defects. METHODS: This was a retrospective review of the antenatal reports, pediatric surgery records and subsequent follow-up information of all cases of omphalocele and gastroschisis diagnosed in a 10-year period in our tertiary referral center. RESULTS: There were 109 cases of abdominal wall defects, including omphalocele in 67 cases and gastroschisis in 42 cases. Of the 67 cases of omphalocele there were 26 (39%) with chromosomal abnormalities and 22 (33%) underwent termination of pregnancy, mainly for associated structural abnormalities. Of the ongoing 19 cases there were five (26%) in-utero deaths, 12 (63%) survivors and two (11%) neonatal deaths, both associated with prematurity. Excluding chromosomal abnormalities, the survival rate in isolated omphalocele was 7/16 (44%) whilst it was 5/25 (20%) in those with associated abnormalities. Gastroschisis was isolated in 40 (95%) cases. Among these 40 isolated cases there were two (5%) terminations. Of the 38 ongoing cases, there were two (5%) in-utero deaths, and 36 (95%) live births. Four of the 36 liveborn infants (11%) died in the postoperative period owing to complications of small bowel atresia. CONCLUSIONS: Although only 18% of infants with antenatally diagnosed omphalocele were alive in the neonatal period, postoperative morbidity was low. The majority (90%) of fetuses with antenatally diagnosed gastroschisis survived to delivery, but the mortality in affected newborns was 11%.

Gastrosquisis: reporte de un caso y revisión bibliográfica / gastroschisis: a case report and literature review

Se presenta el caso de Paciente femenina de 23 años de edad, II gesta, I Para, quien es referida a este centro por hallazgo ecográfico de malformación fetal y oligoamnios severo. Se le diagnóstico gastrosquisis a las 29 semanas a través de un ecograma pélvico. Al momento del ingreso se le realiza un nuevo ecograma, evidenciándose un embarazo de 35 semana por biometría fetal y 37 semanas por FUM, gastrosquisis con esas dilatadas (16 mm), RCF y liquido amniótico en suficiente cantidad; motivo por el cual la paciente es trasladada al servicio de obstetricia. Se planifica la intervención en conjunto con cirugía pediátrica e intensivista pediátrica. Se realiza cesárea segmentarea electiva, obteniéndose recién nacido de sexo femenino en con apgar de 7 pts al minuto y 9 pts a los 5 minutos, con liquido amniótico claro con grumos, se evidencio defecto de cierre de pared anterior con protusión de asas intestinales dilatadas. Se realiza de forma inmediata intervención de cirugía pediátrica, realizándose intento fallido de cierre de pared abdominal, y se coloca bolsa de bogota. Se mantiene en la unidad de cuidados intensivos por 3 días y fallece por sepsis fetal con punto de partida enteral. La madre evoluciona bien en su post operatorio y es dada de alta.

Gastroschisis with fetal chromosomal abnormality: a case report.

Gastroschisis is a rare anomaly and it is usually not associated with other syndromic or nonsyndromic anomalies. The first case of gastroschisis with aneuploidy (Turner syndrome) is presented. A fetal huge cystic hygroma was diagnosed by prenatal sonography at 12 weeks of pregnancy and chorionic villi sampling (CVS) was performed. Cytogenetic analysis revealed 45, X0. The pregnancy was terminated by induction of labor at 16 weeks of pregnancy. The female fetus had a big membrane of cystic hygroma surrounding the fetal neck. Additionally, a full abdominal thickness defect with multiple loops of bowel outside the abdomen, which could not be diagnosed on prenatal ultrasound scan, was detected on postnatal examination.

Transgenerational transmission of radiation damage: genomic instability and congenital malformation.

The congenital malformation gastroschisis has a genetic disposition in the inbred mouse strain HLG/Zte. It is increased after preconceptional irradiation of males or females. Radiation exposures during the meiotic stages are most efficient. This malformation can also be induced by ionising radiation when the exposure takes place during the preimplantation period especially during the zygote stage. This latter effect can be transmitted to the next mouse generation. Other macroscopically visible or skeletal malformations are not significantly induced under these experimental conditions. These latter malformations are increased by radiation exposures during major organogenesis. The mechanisms for the development of the effects are different. Radiation exposure of the mouse zygote (1 to 3 hours p.c.) also leads to the induction of genomic instability in skin fibroblasts of the fetus. This phenomenon also occurs in a mouse strain (C57BL/6J) which is not susceptible to radiation-induced gastroschisis during the preimplantation period. The genomic instability is transmitted to the next mouse generation. During genomic instability chromatide breaks are dominating as in non-exposed cells. With respect to "spontaneous" malformations gastroschisis is dominating in HLG/Zte mice. Late radiation effects seem to have similar patterns as observed in non-exposed subjects, however, the rates are increased after irradiation.