Stuart Hosie

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

PurposeThe 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.MethodsThe 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.ResultsCurrently, 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.ConclusionFirst 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.

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

BackgroundThe 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).MethodsData 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.ResultsIn 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.ConclusionsThere 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.

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.

Screening for depression in adolescent paediatric patients: validity of the new Depression Screener for Teenagers (DesTeen).

BACKGROUND Depression in adolescents is often hard to detect. In many cases paediatricians are the first point of contact. In order to increase recognition rates, screening instruments may be a helpful support for health care professionals. However, there is a lack of valid and economical screening instruments for primary care patients. Thus, the aim of the study was the development of the new Depression Screener for Teenagers (DesTeen) and its validation in a paediatric sample. METHOD 326 patients between 13 and 16 years old completed the DesTeen and a diagnostic interview, serving as gold standard. Prevalence rate for any depressive disorder (minor depression, major depression and dysthymia) was 12.6%. Psychometric properties were calculated. For validity measures, the area under the receiver operating characteristic curves (AUC) for any depressive disorder and the diagnostic subgroups was computed. RESULTS DesTeen showed a high reliability (Cronbachs α=.87) and a high validity (AUC=.91). For the diagnostic subgroups AUC values did not significantly differ from overall accuracy of any depressive disorder (major depression: AUC=.95, p=.179; dysthymia: AUC=.88, p=.605; minor depression: AUC=.87, p=.327). The optimal cut-off point for any depressive disorder according to the Youden-Index yielded a sensitivity of .90 and a specificity of .80. An abbreviated 5-item version of DesTeen showed no loss in validity (AUC=.90, p=.695). CONCLUSIONS Overall, DesTeen can be regarded as a valid screening instrument for adolescent paediatric patients. For practical use, the 5-item version is even more promising. A replication of these results is essential.

De novo duplication of 18p11.21–18q12.1 in a female with anorectal malformation

De Novo Duplication of 18p11.21–18q12.1 in a Female With Anorectal Malformation Charlotte Schramm, Markus Draaken, Enrika Bartels, Thomas M. Boemers, Eberhard Schmiedeke, Sabine Grasshoff-Derr, Stefanie M€arzheuser, Stuart Hosie, Stefan Holland-Cunz, Friederike Baudisch, Lutz Priebe, Per Hoffmann, Alexander M. Zink, Hartmut Engels, Felix F. Brockschmidt, Stefan Aretz, Markus M. N€othen, Michael Ludwig, and Heiko Reutter* Institute of Human Genetics, University of Bonn, Bonn, Germany Department of Genomics, Life and Brain Center, University of Bonn, Bonn, Germany Department of Pediatric Surgery and Pediatric Urology, Children’s Hospital, Cologne, Germany Department of Pediatric Surgery and Urology, Center for Child and Adolescent Health, Hospital Bremen-Mitte, Bremen, Germany Department of Pediatric Surgery, University Hospital W€urzburg, W€urzburg, Germany Department of Pediatric Surgery, Campus Virchow Clinic, Charit e University Hospital Berlin, Berlin, Germany Department of Pediatric Surgery, Klinikum Schwabing, Technische Universit€at M€unchen, M€unchen, Germany Department of Pediatric Surgery, University of Heidelberg, Heidelberg, Germany Department of Clinical Chemistry and Clinical Pharmacology, University of Bonn, Bonn, Germany Department of Neonatology, Children’s Hospital, University of Bonn, Bonn, Germany

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

IntroductionAnorectal 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 methodsWe 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.ConclusionThe 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.

Anal atresia, coloboma, microphthalmia, and nasal skin tag in a female patient with 3.5 Mb deletion of 3q26 encompassing SOX2

A full term female newborn presented with prominent forehead, bilateral microphthalmia, iris coloboma and cataract, wide intercanthal distance, large, low‐set and protruding ears, skin tag at the left nasal nostril, imperforate anus with rectovestibular fistula, and postnatal growth delay with brachymicrocephaly. A marker chromosome was not detectable and the copy number of 22q11 was normal. However, array CGH revealed a 3.5 Mb microdeletion of chromosome region 3q26.32–3q26.33 (chr. 3: 178,598,162–182,114,483; hg19) which comprised the SOX2 gene. While SOX2 haploinsufficiency is known to cause microphthalmia and coloboma, it has not been described before in patients with anal atresia.

Successful treatment of recurrent abdominopelvic neurenteric cysts by OK-432 injection

The case of recurrent intraabdominal neurenteric cyst after surgical excision in an infant is described. After several operative resections, we changed therapeutic strategy and performed local injection of OK-432. Indeed, there is experience with the application of OK-432 for other entities, especially lymphangioma, but to our knowledge, there is no report published so far on the treatment of neurenteric cyst with OK-432. We describe for the first time an effective and simple treatment of recurrent neurenteric cyst.

The role of contractile microfilaments in the morphogenesis of the developing foregut of chick embryos.

Abstract.The cellular processes that lead to changes in shape (morphogenesis) and organ formation (organogenesis) are poorly understood. Local contraction of microfilaments can change cell shape and lead to changes of tissue shape. To clarify the role of contactile microfilaments in the foregut morphogenesis of chick embryos, 2- to 4-day-old embryos were exposed to cytochalasin D (CD), which is known to disrupt microfilaments. Untreated age-matched embryos were used as controls. Sections of treated embryos and controls were stained with phalloidin, which binds to actin, and examined with a fluorescence microscope. Microdissected specimens were examined using a scanning electron microscope (SEM). Immunofluorescent staining showed a bright signal belt toward the apical cell region of the foregut epithelium in controls. This signal was not evident in CD-exposed embryos. SEM micrographs of the controls showed the cranial foregut as a smooth, even, cylindrical structure in all stages studied. The lumen was narrow and perfectly straight, the ventral and dorsal walls were in close apposition. The foregut of CD-exposed specimens, however, showed a wide lumen and the walls were separated from each other. The structure seemed atonic and appeared conical, curved, or tilted. We observed a dense microfilament network toward the apical cell pole of the epithelial foregut cells of controls that was no longer evident after CD exposure. This network seems to play an important role in foregut morphogenesis, since actin-filament disruption by CD causes loss of the normal shape.