CEP162 deficiency causes human retinal degeneration and reveals a dual role in ciliogenesis and neurogenesis.

Defects in primary or motile cilia result in a variety of human pathologies, and retinal degeneration is frequently associated with these so-called ciliopathies. We found that homozygosity for a truncating variant in CEP162, a centrosome and microtubule-associated protein required for transition zone assembly during ciliogenesis and neuronal differentiation in the retina, caused late-onset retinitis pigmentosa in 2 unrelated families. The mutant CEP162-E646R*5 protein was expressed and properly localized to the mitotic spindle, but it was missing from the basal body in primary and photoreceptor cilia. This impaired recruitment of transition zone components to the basal body and corresponded to complete loss of CEP162 function at the ciliary compartment, reflected by delayed formation of dysmorphic cilia. In contrast, shRNA knockdown of Cep162 in the developing mouse retina increased cell death, which was rescued by expression of CEP162-E646R*5, indicating that the mutant retains its role for retinal neurogenesis. Human retinal degeneration thus resulted from specific loss of the ciliary function of CEP162.

Re-sequencing of candidate genes FOXF1, HSPA6, HAAO, and KYNU in 522 individuals with VATER/VACTERL, VACTER/VACTERL-like association, and isolated anorectal malformation.

BACKGROUND: The acronym VATER/VACTERL association describes the combination of at least three component features (CFs): vertebral defects (V), anorectal malformations (ARM) (A), cardiac defects (C), tracheoesophageal fistula with or without esophageal atresia (TE), renal malformations (R), and limb defects (L). Individuals presenting two CFs have been termed VATER/VACTERL-like. Recently, FOXF1, HSPA6, HAAO, KYNU, TRAP1, and ZIC3 have been proposed as candidate genes for VATER/VACTERL, VATER/VACTERL-like, and ARM. Re-sequencing studies identified disease-causing variants in TRAP1 and ZIC3, the contribution of other genes was not independently investigated. One affected variant carrier in FOXF1 was previously identified. Here we re-sequenced FOXF1, HSPA6, HAAO, and KYNU in 522 affected individuals. METHODS: Using molecular inversion probe (MIP) technology, re-sequencing was performed in 63 individuals with VATER/VACTERL association, 313 with VATER/VACTERL-like association, and 146 with ARM. All individuals were of European ethnicity. Variant filtering considered variants with a minor allele frequency (MAF) ≤0.01 for putative recessive disease-genes HSPA6, HAAO, and KYNU. For the putative dominant disease-gene FOXF1 we considered variants with a MAF ≤0.0001. In silico prediction tools were used for further prioritization. RESULTS: Only two variants in FOXF1 in two independently affected individuals [c.443G>T, p.(Cys148Phe); c.850T>C, p.(Tyr284His)] passed our filter criteria. One individual presented with ARM, the second presented with TE and C comprising atrial and ventricular septal defects. Sanger sequencing confirmed both variants but also their inheritance from the healthy mother. CONCLUSION: Our analysis suggests that FOXF1, HSPA6, HAAO and KYNU do not play a major role in the formation of VACTER/VACTERL phenotypes or ARM.

Inter- and Intraobserver Variation in the Assessment of Preoperative Colostograms in Male Anorectal Malformations: An ARM-Net Consortium Survey.

Aim: Male patients with anorectal malformations (ARM) are classified according to presence and level of the recto-urinary fistula. This is traditionally established by a preoperative high-pressure distal colostogram that may be variably interpreted by different surgeons. The aim of this study was to evaluate the inter- and intraobserver variation in the assessment by pediatric surgeons of preoperative colostograms with respect to the level of the recto-urinary fistula. Materials and Methods: Sixteen pediatric surgeons from 14 European centers belonging to the ARM-Net Consortium twice scored 130 images of distal colostograms taken in sagittal projection at a median age of 66 days of life (range: 4-1,106 days). Surgeons were asked to classify the fistula in bulbar, prostatic, bladder-neck, no fistula, and "unclear anatomy" example. Their assessments were compared with the intraoperative findings (kappa) for two scoring rounds with an interval of 6 months (intraobserver variation). Agreement among the surgeons' scores (interobserver variation) was also calculated using Krippendorff's alpha. A kappa over 0.75 is considered excellent, between 0.40 and 0.75 fair to good, and below 0.40 poor. Surgeons were asked to score the images in "poor" and "good" quality and to provide their years of experience in ARM treatment. Results: Agreement between the image-based rating of surgeons and the intraoperative findings ranges from 0.06 to 0.45 (mean 0.31). Interobserver variation is higher (Krippendorff's alpha between 0.40 and 0.45). Years of experience in ARM treatment does not seem to influence the scoring. The mean intraobserver variation between the two rounds is 0.64. Overall, the quality of the images is considered poor. Images categorized as having a good quality result in a statistically significant higher kappa (mean: 0.36 and 0.37 in the first and second round, respectively) than in the group of bad-quality images (mean: 0.25 and 0.23, respectively). Conclusions: There is poor agreement among experienced pediatric colorectal surgeons on preoperative colostograms. Techniques and analyses of images need to be improved in order to generate a homogeneous series of patients and make comparison of outcomes reliable.

Array-based molecular karyotyping in 115 VATER/VACTERL and VATER/VACTERL-like patients identifies disease-causing copy number variations.

BACKGROUND: The acronym VATER/VACTERL refers to the rare nonrandom association of the following component features (CF): vertebral defects (V), anorectal malformations (A), cardiac defects (C), tracheoesophageal fistula with or without esophageal atresia, renal malformations (R), and limb defects (L). Patients presenting with at least three CFs are diagnosed as having VATER/VACTERL association while patients presenting with only two CFs are diagnosed as having VATER/VACTERL-like phenotypes. Recently, rare causative copy number variations (CNVs) have been identified in patients with VATER/VACTERL association and VATER/VACTERL-like phenotypes. METHODS: To detect further causative CNVs we performed array based molecular karyotyping in 75 VATER/VACTERL and 40 VATER/VACTERL-like patients. RESULTS: Following the application of stringent filter criteria, we identified 13 microdeletions and seven microduplications in 20 unrelated patients all of which were absent in 1,307 healthy inhouse controls (n < 0.0008). Among these, microdeletion at 17q12 was confirmed to be de novo. Three microdeletions at 5q23.1, 16q23.3, 22q11.21, and one microduplication at 10q11.21 were all absent in the available parent. Microdeletion of chromosomal region 22q11.21 was previously found in VATER/VACTERL patients rendering it to be causative in our patient. The remaining 15 CNVs were inherited from a healthy parent. CONCLUSION: In two of 115 patients' causative CNVs were found (2%). The remaining identified rare CNVs represent candidates for further evaluation. Rare inherited CNVs may constitute modifiers of, or contributors to, multifactorial VATER/VACTERL or VATER/VACTERL-like phenotypes. Birth Defects Research 109:1063-1069, 2017. © 2017 Wiley Periodicals, Inc.

Genome-wide mapping of copy number variations in patients with both anorectal malformations and central nervous system abnormalities.

BACKGROUND: Anorectal malformations (ARM) have a prevalence of around 1 in 2500 live births. In around 50% of patients, the malformation is isolated, while in the remainder it arises within the context of complex genetic abnormalities or a defined genetic syndrome. Recent studies have implicated rare copy number variations (CNVs) in both isolated and nonisolated ARM, and identified plausible candidate genes. METHODS: In the present study, array-based molecular karyotyping was performed to identify causative CNVs in 32 sporadic ARM patients with comorbid abnormalities of the central nervous system (CNS). This phenotype was selected to enrich for rare CNVs, since previous research has implicated rare CNVs in both CNS abnormalities and ARM. RESULTS: In five patients, a probable disease-causing CNV was identified (del6q14.3q16.3, del14q32.2, del17q12q21.2, and two patients with del22q11.21). In three of these patients, the CNVs were de novo. For the remaining two patients, no parental DNA was available. Deletions at 22q11.21 and 6q14.3 have been associated with both CNS abnormalities and ARM. In contrast, deletions at 14q32.2 have only been described in patients with CNS abnormalities, and the del17q12q21.2 is a novel CNV. Expression studies in mice suggest that NEUROD2 and RARA, which reside within the newly identified del17q12q21.2 region, are candidate genes for the formation of microcephaly and ARM. CONCLUSION: The present data suggest that CNVs are a frequent cause of the ARM with CNS abnormalities phenotype, and that array-analysis is indicated in such patients.

Heterozygous FGF8 mutations in patients presenting cryptorchidism and multiple VATER/VACTERL features without limb anomalies.

BACKGROUND: The acronym VATER/VACTERL association describes the combination of at least three of the following cardinal features: vertebral defects, anorectal malformations, cardiac defects, tracheoesophageal fistula with or without esophageal atresia, renal malformations, and limb defects. Although fibroblast growth factor-8 (FGF8) mutations have mainly found in patients with Kallmann syndrome, mice with a hypomorphic Fgf8 allele or complete gene invalidation display, aside from gonadotropin-releasing hormone deficiency, parts or even the entire spectrum of human VATER/VACTERL association. METHODS: We performed FGF8 gene analysis in 49 patients with VATER/VACTERL association and 27 patients presenting with a VATER/VACTERL-like phenotype (two cardinal features). RESULTS: We identified two heterozygous FGF8 mutations in patients displaying either VATER/VACTERL association (p.Gly29_Arg34dup) or a VATER/VACTERL-like phenotype (p.Pro26Leu) without limb anomalies. Whereas the duplication mutation has not been reported before, p.Pro26Leu was once observed in a Kallmann syndrome patient. Both our patients had additional bilateral cryptorchidism, a key phenotypic feature in males with FGF8 associated Kallmann syndrome. Each mutation was paternally inherited. Besides delayed puberty in both and additional unilateral cryptorchidism in one of the fathers, they were otherwise healthy. Serum hormone levels downstream the gonadotropin-releasing hormone in both patients and their fathers were within normal range. CONCLUSION: Our results suggest FGF8 mutations to contribute to the formation of the VATER/VACTERL association. Further studies are needed to support this observation.

Whole-exome resequencing reveals recessive mutations in TRAP1 in individuals with CAKUT and VACTERL association.

Congenital abnormalities of the kidney and urinary tract (CAKUT) account for approximately half of children with chronic kidney disease and they are the most frequent cause of end-stage renal disease in children in the US. However, its genetic etiology remains mostly elusive. VACTERL association is a rare disorder that involves congenital abnormalities in multiple organs including the kidney and urinary tract in up to 60% of the cases. By homozygosity mapping and whole-exome resequencing combined with high-throughput mutation analysis by array-based multiplex PCR and next-generation sequencing, we identified recessive mutations in the gene TNF receptor-associated protein 1 (TRAP1) in two families with isolated CAKUT and three families with VACTERL association. TRAP1 is a heat-shock protein 90-related mitochondrial chaperone possibly involved in antiapoptotic and endoplasmic reticulum stress signaling. Trap1 is expressed in renal epithelia of developing mouse kidney E13.5 and in the kidney of adult rats, most prominently in proximal tubules and in thick medullary ascending limbs of Henle's loop. Thus, we identified mutations in TRAP1 as highly likely causing CAKUT or VACTERL association with CAKUT.

First results of a European multi-center registry of patients with anorectal malformations.

BACKGROUND: The European consortium on anorectal malformations (ARM-NET) was established to improve the health care of patients and to identify genetic and environmental risk factors. The aim of the present study was to present the first results on clinical data of a large European cohort of ARM patients based on our registry. METHODS: In 2010, the registry was established including patient characteristics and data on diagnosis, surgical therapy, and outcome regarding complications. Patients born between 2007 and 2012 were retrospectively added. A descriptive analysis of this cohort was performed. RESULTS: Two hundred and three ARM patients were included. Syndromes or chromosomal abnormalities were present in 9%. Perineal fistulas were seen most in boys (42%) and girls (29%). Rare forms of ARM were found in 4% of the male and in 14% of the female patients. Forty-five percent of the patients had additional urogenital abnormalities. However, 32% of the patients were never screened for bladder abnormalities. Eight percent were never screened for renal malformations. In the majority of patients (79%), a PSARP was performed for the definitive reconstruction. CONCLUSION: This collaborative effort provides a representative basis to estimate incidence of ARM types, to discuss differences and similarities in treatment, and health consequences throughout Europe.

De novo 13q deletions in two patients with mild anorectal malformations as part of VATER/VACTERL and VATER/VACTERL-like association and analysis of EFNB2 in patients with anorectal malformations.

Anorectal malformations (ARMs) comprise a broad spectrum of conditions ranging from mild anal anomalies to complex cloacal malformations. In 40-50% of cases, ARM occurs within the context of defined genetic syndromes or complex multiple congenital anomalies, such as VATER/VACTERL (vertebral defects [V], ARMs [A], cardiac defects [C], tracheoesophageal fistula with or without esophageal atresia [TE], renal malformations [R], and limb defects [L]) association. Here, we report the identification of deletions at chromosome 13q using single nucleotide polymorphism-based array analysis in two patients with mild ARM as part of VATER/VACTERL and VATER/VACTERL-like associations. Both deletions overlap the previously defined critical region for ARM. Heterozygous Efnb2 murine knockout models presenting with mild ARM suggest EFNB2 as an excellent candidate gene in this region. Our patients showed a mild ARM phenotype, closely resembling that of the mouse. We performed a comprehensive mutation analysis of the EFNB2 gene in 331 patients with isolated ARM, or ARM as part of VATER/VACTERL or VATER/VACTERL-like associations. However, we did not identify any disease-causing mutations. Given the convincing argument for EFNB2 as a candidate gene for ARM, analyses of larger samples and screening of functionally relevant non-coding regions of EFNB2 are warranted. In conclusion, our report underlines the association of chromosome 13q deletions with ARM, suggesting that routine molecular diagnostic workup should include the search for these deletions. Despite the negative results of our mutation screening, we still consider EFNB2 an excellent candidate gene for contributing to the development of ARM in humans.

De novo microduplications at 1q41, 2q37.3, and 8q24.3 in patients with VATER/VACTERL association.

The acronym VATER/VACTERL association describes the combination of at least three of the following congenital anomalies: vertebral defects (V), anorectal malformations (A), cardiac defects (C), tracheoesophageal fistula with or without esophageal atresia (TE), renal malformations (R), and limb defects (L). We aimed to identify highly penetrant de novo copy number variations (CNVs) that contribute to VATER/VACTERL association. Array-based molecular karyotyping was performed in a cohort of 41 patients with VATER/VACTERL association and 6 patients with VATER/VACTERL-like phenotype including all of the patients' parents. Three de novo CNVs were identified involving chromosomal regions 1q41, 2q37.3, and 8q24.3 comprising one (SPATA17), two (CAPN10, GPR35), and three (EPPK1, PLEC, PARP10) genes, respectively. Pre-existing data from the literature prompted us to choose GPR35 and EPPK1 for mouse expression studies. Based on these studies, we prioritized GPR35 for sequencing analysis in an extended cohort of 192 patients with VATER/VACTERL association and VATER/VACTERL-like phenotype. Although no disease-causing mutation was identified, our mouse expression studies suggest GPR35 to be involved in the development of the VATER/VACTERL phenotype. Follow-up of GPR35 and the other genes comprising the identified duplications is warranted.

Assisted reproductive techniques and the risk of anorectal malformations: a German case-control study.

BACKGROUND: The use of assisted reproductive techniques (ART) for treatment of infertility is increasing rapidly worldwide. However, various health effects have been reported including a higher risk of congenital malformations. Therefore, we assessed the risk of anorectal malformations (ARM) after in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). METHODS: Data of the German Network for Congenital Uro-REctal malformations (CURE-Net) were compared to nationwide data of the German IVF register and the Federal Statistical Office (DESTATIS). Odds ratios (95% confidence intervals) were determined to quantify associations using multivariable logistic regression accounting for potential confounding or interaction by plurality of births. RESULTS: In total, 295 ARM patients born between 1997 and 2011 in Germany, who were recruited through participating pediatric surgeries from all over Germany and the German self-help organisation SoMA, were included. Controls were all German live-births (n = 10,069,986) born between 1997 and 2010. Overall, 30 cases (10%) and 129,982 controls (1%) were born after IVF or ICSI, which translates to an odds ratio (95% confidence interval) of 8.7 (5.9-12.6) between ART and ARM in bivariate analyses. Separate analyses showed a significantly increased risk for ARM after IVF (OR, 10.9; 95% CI, 6.2-19.0; P < 0.0001) as well as after ICSI (OR, 7.5; 95% CI, 4.6-12.2; P < 0.0001). Furthermore, separate analyses of patients with isolated ARM, ARM with associated anomalies and those with a VATER/VACTERL association showed strong associations with ART (ORs 4.9, 11.9 and 7.9, respectively). After stratification for plurality of birth, the corresponding odds ratios (95% confidence intervals) were 7.7 (4.6-12.7) for singletons and 4.9 (2.4-10.1) for multiple births. CONCLUSIONS: There is a strongly increased risk for ARM among children born after ART. Elevations of risk were seen after both IVF and ICSI. Further, separate analyses of patients with isolated ARM, ARM with associated anomalies and those with a VATER/VACTERL association showed increased risks in each group. An increased risk of ARM was also seen among both singletons and multiple births.

Unexpected results of a nationwide, treatment-independent assessment of fecal incontinence in patients with anorectal anomalies.

PURPOSE: To determine the anorectal function in patients with anorectal malformations (ARM) in order to facilitate patient counseling and follow-up. METHODS: Data were collected by the German network for urorectal malformations (CURE-Net) according to the International Krickenbeck consensus. Questionnaires on bowel function and a defecation protocol were completed by the families/patients. The clinical findings were assessed from the patients' clinical records. RESULTS: Two hundred and ninety-seven patients with ARM were assessed, 175 patients gave complete data on continence, 52 of them were excluded due to mental retardation, age, and earlier type of pullthrough. Complete continence was found in 27 %, perineal fistula in 40 %, rectourethral/vesical in 10 %, vestibular in 24 %, cloaca in 0 %. Krickenbeck grade 1 soiling: 42 %, grade 2 and 3: 31 %. Forty-nine percent of the incontinent patients practiced bowel management, reaching continence in 19 %. The statement of constipation (67 %) was validated with the last clinical findings, showing coprostasis in 46 %, "Not suffering constipation" was confirmed in 61 % and falsified in 29 %. CONCLUSION: ARM patients in Germany, as assessed by independent researchers, show a high rate of fecal incontinence and insufficiently treated constipation. Parents should be counseled accordingly and motivated to engage in consequent follow-up. Intensified efforts in the conservative treatment of constipation and fecal incontinence are crucial to improvement.

Inheritance of the VATER/VACTERL association.

VATER/VACTERL association refers to the non-random co-occurrence of the following component features: vertebral defects, anal atresia, cardiac malformations, tracheoesophageal atresia, renal abnormalities, and limb defects. Recently, Solomon et al. (Hum Genet 127:731-733, 2010) observed an increased prevalence of component features among first-degree relatives of VATER/VACTERL patients suggesting that in some patients, the disorder may be inherited. To replicate these findings, we investigated 87 VATER/VACTERL patients with the presence of a minimum of three component features and their first-degree relatives (n = 271). No increase in the overall prevalence of component features was observed in first-degree relatives compared to the general population (χ² = 2.68, p = 0.10). Separate analysis for the prevalence of single component features showed a higher prevalence of tracheoesophageal fistula/atresia among first-degree relatives compared to the general population (OR 17.65, 95% CI 2.47-126.05). However, this was based on occurrence in one family only. Our findings suggest that although familial occurrence renders a genetic contribution likely, the overall risk of recurrence among the first-degree relatives of patients with VATER/VACTERL association is probably very low. Since the patients in the present study were young and no offspring could be studied, estimation of the role of de novo mutations in the development of VATER/VACTERL was not possible.

A successful treatment strategy in infants and adolescents with anorectal malformation and incontinence with combined hydrocolonic ultrasound and bowel management.

PURPOSE: Patients with anorectal malformation (ARM) frequently suffer postoperatively from fecal incontinence (25%) and constipation (75%). Depending on the type of malformation, some cases will not have a chance to control bowel movements. For these patients with fecal incontinence, we started to combine bowel management with hydrocolonic ultrasound to keep them clean. MATERIAL: From January 2003 until December 2010, overall 63 patients (aged 4-22 years) with ARM and fecal incontinence were treated by specific bowel management. Hydrocolonic ultrasound was used as a diagnostic parameter to determine stool texture and activity of the colon as well as to determine the appropriate volume which is needed to clean the colon. Each patient received an individually adjusted enema. Patients were classified into two groups: Group I: patients with incontinence and tendency to constipation and Group II: patients with incontinence and tendency to diarrhea. Subsequent controls were focused on problems such as bowel dilatation, bowel motility, constipation or too little enema due to the patient's growing. RESULTS: Up to now, 63 patients were investigated in our study (Group I n = 37 patients and Group II n = 26 patients). In addition, the patients were classified according to the type of malformation. With specific bowel management combined with hydrocolonic ultrasound, 97% of patients in Group I (36/37) stayed clean (demonstration of complete bowel control). All 57.7% of patients in Group II (15/26) stayed clean after daily bowel management, and 34.6% with smearing less than three times per week (n = 9/26). In addition, a specific diet and constipating medication were often necessary to get patients in Group II clean. CONCLUSIONS: Treating young patients with fecal incontinence is always a challenge. Hydrocolonic ultrasound diagnostically conclusive and less invasive. The combination with bowel management results in better bowel control and serves as a valuable tool in affected infants and adolescents. Thus, hydrocolonic ultrasound may be an essential instrument in postoperative diagnostic procedure and therapy of patients with fecal incontinence.

German network for congenital uro-rectal malformations: first evaluation and interpretation of postoperative urological complications in anorectal malformations.

OBJECTIVE: The aim of the German Network for Congenital Uro-REctal Malformations is to collect data of affected patients with anorectal malformation (ARM) or extrophy-epispadias complex, and to investigate molecular causes, clinical implications, and psychosocial outcome. The current issue was to assess the postoperative sequelae related to lower urinary tract dysfunction in patients with ARM. MATERIALS AND METHODS: Two hundred and sixty-seven patients with ARM (112 females, 155 males, median age 6 years, range 0-56 years) were investigated via standardized case report forms comprising interview, analysis of medical data, and personal questionnaires. RESULTS: Thirty-two patients (12%, 23 males, 9 females) suffered from neurogenic bladder dysfunction, mainly associated with recto-urethral fistula (11 cases, 34%), and recto-vesical fistula (6 cases, 19%). Sixty-eight patients (26%, 35 males, 57 females) have experienced lifetime urinary tract infection, primarily associated with recto-urethral fistula (21 cases, 31%), and vestibular fistula (13 cases, 19%). According to type of operation, the highest number of postoperative urologic problems was reported after abdominosacroperineal pull-through. CONCLUSION: Besides reconstructing the ARM, another main goal is the preservation of lower urinary tract function. In our data, there seems to be a close correlation between operative strategies and postoperative complications.

Autosomal-dominant non-syndromic anal atresia: sequencing of candidate genes, array-based molecular karyotyping, and review of the literature.

INTRODUCTION: Anorectal malformations (ARM) range from mild anal to severe anorectal anomalies. Approximately 50% are estimated to be non-syndromic with multiple familial cases reported that suggest underlying genetic factors. These, however, still await identification. MATERIALS AND METHODS: We report a familial case of non-syndromic ARM with a mother and her two children being affected. Mother and daughter had mild ARM that had only been diagnosed after the index patient was born with a more severe form and ultrashort Hirschsprung's disease. To reveal the genetic cause in our family genome-wide array analysis was carried out to ascertain microaberrations characterized by loss or gain of genomic material. In addition, sequence analysis of four major Hirschsprung's disease genes (RET, EDNRB, EDN3, and GDNF) and the HLXB9 gene was performed to identify a mutation common to all three family members; however, these analyses did not reveal any causal genetic alteration. To demonstrate the frequency of familial non-syndromic cases, we performed a literature search revealing 59 families with at least two affected members. Sufficient description of ARM phenotype and affection status of relatives to surely classify them as familial non-syndromic forms was given for 22 families. CONCLUSION: The present family suggests that mild ARM may be overlooked in patients with non-specific clinical symptoms and that the incidence of ARM may thus be higher than previously estimated. With the new possibilities of whole exome sequencing, even small families hold the possibility to identify causal defects.

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.

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.