Research perspectives in the etiology of congenital anorectal malformations using data of the International Consortium on Anorectal Malformations: evidence for risk factors across different populations

Contains fulltext : 89406.pdf (publisher's version ) (Closed access)PURPOSE: The recently established International Consortium on Anorectal Malformations aims to identify genetic and environmental risk factors in the etiology of syndromic and nonsyndromic anorectal malformations (ARM) by promoting collaboration through data sharing and combined research activities. METHODS: The consortium attempts to recruit at least 1,000 ARM cases. DNA samples are collected from case-parent triads to identify genetic factors involved in ARM. Several genetic techniques will be applied, including SNP arrays, gene and whole exome sequencing, and a genome-wide association study. Questionnaires inquiring about circumstances before and during pregnancy will be used to obtain environmental risk factor data. RESULTS: Currently, 701 ARM cases have been recruited throughout Europe. Clinical data are available from all cases, and DNA samples and questionnaire data mainly from the Dutch and German cases. Preliminary analyses on environmental risk factors in the Dutch and German cohort found associations between ARM and family history of ARM, fever during first trimester of pregnancy and maternal job exposure to cleaning agents and solvents. CONCLUSION: First results show that both genetic and environmental factors may contribute to the multifactorial etiology of ARM. The International Consortium on Anorectal Malformations will provide possibilities to study and detect important genes and environmental risk factors for ARM, ultimately resulting in better genetic counseling, improved therapies, and primary prevention.1 november 201

Parental Subfertility, Fertility Treatment, and the Risk of Congenital Anorectal Malformations

Background: Fertility treatment seems to play a role in the etiology of congenital anorectal malformations, but it is unclear whether the underlying parental subfertility, ovulation induction, or the treatment itself is involved. Therefore, we investigated the odds of anorectal malformations among children of subfertile parents who conceived with or without treatment compared with fertile parents. Methods: We performed a case-control study among 380 cases with anorectal malformations treated at 3 departments of pediatric surgery in The Netherlands and 1973 population-based controls born between August 1988 and August 2012. Parental questionnaires were used to obtain information on fertility-related issues and potential confounders. Results: In singletons, increased risks of anorectal malformations were observed for parents who underwent intracytoplasmic sperm injection (ICSI) or in vitro fertilization (IVF) treatment compared with fertile parents (odds ratio = 2.4 [95% confidence interval = 1.0-5.9] and 4.2 [1.9-8.9], respectively). For subfertile parents who conceived after IVF treatment, an elevated risk was also found when they were compared with subfertile parents who conceived without treatment (3.2 [1.4-7.2]). Among children of the latter category of parents, only the risk of anorectal malformations with other major congenital malformations was increased compared with fertile parents (2.0 [1.3-3.3]). No associations were found with intrauterine insemination or use of hormones for ovulation induction. Conclusions: We found evidence of a role of ICSI and IVF treatments in the etiology of anorectal malformations. However, subfertility without treatment increased only the risk of anorectal malformations with additional congenital malformations

Previous miscarriages and GLI2 are associated with anorectal malformations in offspring

STUDY QUESTION: Are anorectal malformations (ARMs) associated with previous miscarriages or single nucleotide polymorphisms (SNPs) in the Bone Morphogenetic Protein 4 (BMP4) and GLI family zinc finger 2 (GLI2) genes? SUMMARY ANSWER: The SNP rs3738880 in GLI2 and miscarriages were associated with ARM, especially in patients with multiple congenital anomalies (MCA). WHAT IS KNOWN ALREADY: ARM are one of the most common birth defects of the gastrointestinal tract. The etiology is likely to be multifactorial, involving both environmental and genetic factors. SNPs in BMP4 and GLI2 genes were associated with ARM in non-Caucasian populations. During a patient information day, several mothers of ARM patients reported their concerns about previous miscarriages. STUDY DESIGN, SIZE, DURATION: A case-control study was performed among 427 ARM patients and 663 population-based controls. PARTICIPANTS/MATERIALS, SETTING, METHODS: We examined the associations of ARM with SNPs in GLI2 and BMP4 using DNA samples of the children and associations with previous miscarriages using parental questionnaires. In addition, gene-gene and geneenvironment interaction analyses were performed. MAIN RESULTS AND THE ROLE OF CHANCE: The SNP rs3738880 in GLI2 was associated with ARM, especially in patients with MCA (homozygous GG-genotype: odds ratio (OR): 2.1; 95% CI: 1.2, 3.7). We identified previous miscarriages as a new risk factor for ARM, especially when occurring in the pregnancy directly preceding the index pregnancy and in patients with MCA (OR: 2.1; 95% CI: 1.3, 3.5). No association with rs17563 in BMP4, nor gene-gene or gene-environment interactions were found. LIMITATIONS, REASONS FOR CAUTION: The possibility of recall errors for previous miscarriage, but we expect these errors to be limited, as a miscarriage is a major life event. In addition, potential misclassification regarding miscarriages and stillbirth, but sensitivity analyses showed that this did not influence our results. WIDER IMPLICATIONS OF THE FINDINGS: This study showed associations of ARM with rs3738880 in GLI2 and with previous miscarriages. Both associations were stronger in patients with MCA, showing the importance of stratifying the analyses by patients with isolated ARM or MCA. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by the Radboudumc. The authors have no conflict of interest to disclose

More than fetal urine:enteral uptake of amniotic fluid as a major predictor for fetal growth during late gestation

Item does not contain fulltextThe purpose of our study was to investigate the importance of amniotic fluid (AF) for fetal growth during late gestation using esophageal atresia (EA) patients as a model. In this retrospective cohort study, we compared the z-scores adapted for birth weights (BW z-scores) for each of 517 European newborns with congenital pre-gastric intestinal atresia, i.e., EA, to a European reference population. To account for the influence of the intestinal atresia on fetal growth per se, we compared adapted birth weights for each of 504 European newborns with post colonic intestinal atresia (anorectal malformation (ARM) with atresia of the anus) to the same European reference population. Analysis of the complete cohort showed (i) a significantly higher rate of small for gestational age newborns among EA compared to ARM newborns (p < 0.001) and (ii) significantly lower BW z-scores among EA compared to ARM newborns (p < 0.001). BW z-scores of EA newborns were significantly lower in term compared to preterm newborns with an inverse correlation with gestational age (GA) (Spearman correlation coefficient, r = -0.185, p < 0.001). CONCLUSIONS: Enteral uptake of AF seems to play a pivotal role in fetal growth during late gestation. WHAT IS KNOWN: * Peak velocity of fetal weight gain occurs at 33 weeks of gestation and continues until birth. During this period, fetal growth is mainly characterized by cellular hypertrophy. * Amniotic fluid (AF) comprises large amounts of hormones and growth regulators. What is New: * A significantly higher rate of small for gestational age and lower birth weights and z-scores are observed among newborn infants with congenital pre-gastric intestinal atresia. * These findings suggest that enteral uptake of AF is a major predictor for fetal growth during late gestation

Exome chip association study excluded the involvement of rare coding variants with large effect sizes in the etiology of anorectal malformations

Introduction Anorectal malformations (ARM) are rare congenital malformations, resulting from disturbed hindgut development. A genetic etiology has been suggested, but evidence for the involvement of specific genes is scarce. We evaluated the contribution of rare and low-frequency coding variants in ARM etiology, assuming a multifactorial model. Methods We analyzed 568 Caucasian ARM patients and 1,860 population-based controls using the Illumina Human Exome Beadchip array, which contains >240,000 rare and low-frequency coding variants. GenomeStudio clustering and calling was followed by re-calling of 'no-calls' using zCall for patients and controls simultaneously. Single variant and gene-based analyses were performed to identify statistically significant associations, applying Bonferroni correction. Following an extra quality control step, candidate variants were selected for validation using Sanger sequencing. Results When we applied a MAF of >= 1.0%, no variants or genes showed statistically significant associations with ARM. Using a MAF cut-off at 0.4%, 13 variants initially reached statistical significance, but had to be discarded upon further inspection: ten variants represented calling errors of the software, while the minor alleles of the remaining three variants were not confirmed by Sanger sequencing. Conclusion Our results show that rare and low-frequency coding variants with large effect sizes, present on the exome chip do not contribute to ARM etiology

AGORA, a data- and biobank for birth defects and childhood cancer

BACKGROUNDResearch regarding the etiology of birth defects and childhood cancer is essential to develop preventive measures, but often requires large study populations. Therefore, we established the AGORA data- and biobank in the Netherlands. In this study, we describe its rationale, design, and ongoing data collection. METHODSChildren diagnosed with and/or treated for a structural birth defect or childhood cancer and their parents are invited to participate in the AGORA data- and biobank. Controls are recruited through random sampling from municipal registries. The parents receive questionnaires about demographics, family and pregnancy history, health status, prescribed medication, lifestyle, and occupational exposures before and during the index pregnancy. In addition, blood or saliva is collected from children and parents, while medical records are reviewed for diagnostic information. RESULTSSo far, we have collected data from over 6,860 families (3,747 birth defects, 905 childhood cancers, and 2,208 controls). The types of birth defects vary widely and comprise malformations of the digestive, respiratory, and urogenital tracts as well as facial, cardiovascular, kidney, skeletal, and central nervous system anomalies. The most frequently occurring childhood cancer types are acute lymphatic leukemia, Hodgkin and non-Hodgkin lymphoma, Wilms' tumor, and brain and spinal cord tumors. Our genetic and/or epidemiologic studies have been focused on hypospadias, anorectal malformations, congenital anomalies of the kidney and urinary tract (CAKUT), and orofacial clefts. CONCLUSIONThe large AGORA data- and biobank offers great opportunities for investigating genetic and nongenetic risk factors for disorders in children and is open to collaborative initiatives. Birth Defects Research (Part A) 106:675-684, 2016. (c) 2016 Wiley Periodicals, Inc