A review of genetic factors contributing to the etiopathogenesis of anorectal malformations

Anorectal malformations

Anorectal malformations (ARM) are rare congenital anomalies with an overall prevalence of 3.32 per 10,000 pregnancies. ARM describe a spectrum of anomalies of the anus and rectum ranging from a minimally displaced anal canal to a complete fusion of the anorectum, vagina and urethra with hypoplastic sphincter and pelvic floor muscle. Aberrant septation of the hindgut with anomalous cloacal membrane during weeks 6 to 9 of gestation form the developmental basis for a spectrum of anomalies defined as ARM. Although underlying specific syndromes and occasional familiar occurrence suggest genetic aetiology, most ARM are non-syndromic and their causal genetic mechanisms and non-genetic insults remain unclear. ARM is a clinical diagnosis, generally made early after birth via careful inspection of the perineum. Prenatal detection remains rare, and modern technical developments have added little to prenatal diagnostics. ARM is corrected surgically. Since its introduction in 1982, posterior sagittal anorectoplasty is the most common surgery for ARM reconstruction. Subsequent surgical adaptations focus on minimizing iatrogenic operative injury by limiting surgical invasiveness. They include laparoscopic procedures and shortening of incisions with confined dissection in open surgery. Although outcomes in patients with ARM have evolved throughout the past decades, there is urgent need for further improvements both in functional outcomes and quality of life. The importance of psychosocial experiences of affected patients is increasingly recognized. Continued research is necessary to improve prenatal detection, to elucidate genetic and epigenetic alterations and to refine optimal surgical procedures.

Rack1-mediated ferroptosis affects hindgut development in rats with anorectal malformations: Spatial transcriptome insights

Anorectal malformation (ARM), a common congenital anomaly of the digestive tract, is a result of insufficient elongation of the urorectal septum. The cytoplasmic protein Receptor of Activated C-Kinase 1 (Rack1) is involved in embryonic neural development; however, its role in embryonic digestive tract development and ARM formation is unexplored. Our study explored the hindgut development and cell death mechanisms in ARM-affected rats using spatial transcriptome analysis. We induced ARM in rats by administering ethylenethiourea via gavage on gestational day (GD) 10. On GDs 14-16, embryos from both normal and ARM groups underwent spatial transcriptome sequencing, which identified key genes and signalling pathways. Rack1 exhibited significant interactions among differentially expressed genes on GDs 15 and 16. Reduced Rack1 expression in the ARM-affected hindgut, verified by Rack1 silencing in intestinal epithelial cells, led to increased P38 phosphorylation and activation of the MAPK signalling pathway. The suppression of this pathway downregulated Nqo1 and Gpx4 expression, resulting in elevated intracellular levels of ferrous ions, reactive oxygen species (ROS) and lipid peroxides. Downregulation of Gpx4 expression in the ARM hindgut, coupled with Rack1 co-localisation and consistent mitochondrial morphology, indicated ferroptosis. In summary, Rack1, acting as a hub gene, modulates ferrous ions, lipid peroxides, and ROS via the P38-MAPK/Nqo1/Gpx4 axis. This modulation induces ferroptosis in intestinal epithelial cells, potentially influencing hindgut development during ARM onset.

Chromosome Microarray Analysis and Exome Sequencing: Implementation in Prenatal Diagnosis of Fetuses with Digestive System Malformations

(1) Purpose: Retrospective back-to-back comparisons were performed to evaluate the accuracy, effectiveness, and incremental yield of chromosome microarray analysis (CMA) and exome sequencing (ES) analysis in fetuses with digestive system malformations (DSMs). (2) Methods: In total, 595 women with fetal DSMs who underwent prenatal diagnosis were enrolled. We analyzed the diagnostic yields of CMA and ES and evaluated pregnancy outcomes. Copy number variants (CNVs) were classified according to the American College of Medical Genetics and Genomics guidelines. (3) Results: Pathogenic CNVs were detected in 11/517 (2.12%) fetuses, and variants of unknown significance (VUS) were identified in 69 (13.35%) fetuses using CMA. ES detected 29 pathogenic/likely pathogenic variants in 23/143 (16.08%) fetuses and 26/143 (18.2%) VUS. In those with other ultrasound abnormalities, the detection rate of multiple system structural malformations was 41.2%, followed by skeletal (33.3%), cardiovascular (25.4%), and central nervous system (18.6%) malformations. Of the 391 surviving children, 40 (10.2%) exhibited varying degrees of mental retardation. (4) Conclusion: A correlation exists between DSMs and chromosomal abnormalities. When combined with other systemic abnormalities, the incidence of chromosomal abnormalities increases significantly. Patients with congenital DSM are at risk of developing neurodevelopmental disorders. Combined CMA and ES detection of fetal DSM has good clinical application potential.

CircJag1 promotes apoptosis of ethylene thiourea-exposed anorectal malformations through sponging miR-137-3p by regulating Sox9 and suppressing Wnt/β-catenin pathway during the hindgut development of rat embryos

Anorectal malformations (ARMs) are common birth defects involving congenital structural anomalies of the gastrointestinal tract. As an important component of non-coding RNAs, circular RNAs (circRNAs) widely participate in the digestive system development; however, the specific molecular mechanism of their involvement in ARM occurrence remains obscure. Herein, we generated rat models of ARMs induced by ethylene thiourea. A novel circRNA (circJag1) was screened and identified by RNA-Seq, which is remarkably upregulated in hindgut tissues of ARM rat embryos. In vivo experiments, colocation analysis via fluorescence in situ hybridization, and immunofluorescence further demonstrated that the disordered circJag1/miR-137-3p/Sox9 expression caused a spatiotemporal imbalance in the urorectal septum (URS) of ARMs. In vitro, functional assays confirmed that circJag1 upregulation resulted in the degradation of nuclear β-catenin, C-myc, and Cyclin D1 in rat intestinal epithelial cells, as well as the promotion of apoptosis and suppression of cell proliferation. Mechanistically, dual-luciferase reporter assay and RNA immunoprecipitation assay indicated that circJag1 acted as a miR-137-3p sponge, thereby inhibiting its repressive effect on its target Sox9. Further experiments showed that a loss of Sox9 abolished the circJag1-mediated increase in apoptosis. In conclusion, aberrantly high circJag1 expression promotes epithelial apoptosis by suppressing the canonical Wnt/β-catenin pathway via the miR-137-3p/Sox9 axis, which leads to fusion failure of the URS and cloacal membrane, and eventually contributed to ARMs. Our achievements might boost the comprehension of ARM pathogenesis and could provide a novel candidate target for the development of therapies for ARMs to complement surgical treatment.

High molecular diagnostic yields and novel phenotypic expansions involving syndromic anorectal malformations

Evidence suggests that genetic factors contribute to the development of anorectal malformations (ARMs). However, the etiology of the majority of ARMs cases remains unclear. Exome sequencing (ES) may be underutilized in the diagnostic workup of ARMs due to uncertainty regarding its diagnostic yield. In a clinical database of ~17,000 individuals referred for ES, we identified 130 individuals with syndromic ARMs. A definitive or probable diagnosis was made in 45 of these individuals for a diagnostic yield of 34.6% (45/130). The molecular diagnostic yield of individuals who initially met criteria for VACTERL association was lower than those who did not (26.8% vs 44.1%; p = 0.0437), suggesting that non-genetic factors may play an important role in this subset of syndromic ARM cases. Within this cohort, we identified two individuals who carried de novo pathogenic frameshift variants in ADNP, two individuals who were homozygous for pathogenic variants in BBS1, and single individuals who carried pathogenic or likely pathogenic variants in CREBBP, EP300, FANCC, KDM6A, SETD2, and SMARCA4. The association of these genes with ARMs was supported by previously published cases, and their similarity to known ARM genes as demonstrated using a machine learning algorithm. These data suggest that ES should be considered for all individuals with syndromic ARMs in whom a molecular diagnosis has not been made, and that ARMs represent a low penetrance phenotype associated with Helsmoortel-van der Aa syndrome, Bardet-Biedl syndrome 1, Rubinstein-Taybi syndromes 1 and 2, Fanconi anemia group C, Kabuki syndrome 2, SETD2-related disorders, and Coffin-Siris syndrome 4.

Colonic tubular duplication combined with congenital megacolon: A case report

BACKGROUND

Colonic duplication refers to a spherical or tubular cavity which shows similar properties with the native colon and is attached to the mesenteric side of the alimentary tract. It is the rarest in alimentary tract duplications. Based upon anatomic feature, colonic duplications can be classified as spherical (cystic) or tubular, with the latter being less common (approximately 20%). Symptoms of colonic duplication are dependent on the duplication site and extent, and patient age, etc. Usually, patients with colonic duplication manifest typical intestinal obstruction, potentially accompanied by recurrent dark or bright red bloody stool, varying degrees of anemia-related symptoms, and body wasting.

CASE SUMMARY

A young male patient was admitted to our hospital due to recurrent abdominal pain. No definite diagnosis was achieved by computed tomography (CT) or electronic colonoscopy, and the bowel preparation efficacy was suboptimal. Hirschsprung disease was suspected, and thus laparoscopic exploration was performed. An approximately 60-cm-long inverted duplicated colon with severe edema and dilation was identified. It originated from the mesenteric side of the transverse colon and ended in the terminal part of the descending colon with a blind end. The parallel native colon had a thickened colonic wall, became stiff, and was poor in peristalsis. The patient then underwent subtotal colectomy and was discharged 7 d after the surgery. From 3 mo post-surgery to date, the patient had regular bowel movement once daily and a steady increase in body weight.

CONCLUSION

Tubular colonic duplication is a rare type of alimentary tract duplication that can be detected by ultrasonography, CT, or magnetic resonance imaging based on the actual clinical situation. Surgical resection of aberrant colon (including the duplicated colonic segment and other potentially involved colonic segments) is the only approach to cure this medical condition.

miR-141-3p affects β-catenin signaling and apoptosis by targeting Ubtd2 in rats with anorectal malformations

Anorectal malformations (ARMs) are the most common gastrointestinal malformations. miR-141-3p was obtained from whole-transcriptome sequencing, and Ub domain-containing protein 2 (Ubtd2) was predicted as the target gene. An ARM rat model was induced using ethylenethiourea. Fluorescence in situ hybridization and immunofluorescence were used to detect the spatiotemporal expression of miR-141-3p and Ubtd2, respectively. A dual-luciferase reporter assay confirmed their targeting relationship, and cell proliferation and apoptosis were investigated after transfection in the intestinal epithelium (IEC-6). Additionally, western blotting and co-immunoprecipitation were used to examine the protein levels and the endogenous binding relationship. miR-141-3p was downregulated in the ARM group, whereas Ubtd2 increased and colocalized with TUNEL-positive cells. After miR-141-3p inhibition, protein expression of USP5 and β-catenin was affected via Ubtd2, and USP5 could bind to both Ubtd2 and β-catenin. Flow cytometry analysis and caspase 3/7 staining demonstrated that downregulated miR-141-3p promoted cell apoptosis through Ubtd2. In summary, targeting Ubtd2 decreased in miR-141-3p and promoted apoptosis of intestinal epithelium and regulated β-catenin expression. This may cause aberrant apoptosis during hindgut development and mediate the imbalance of β-catenin signaling in the cloaca, further affecting the occurrence of ARMs.

Embryology and anatomy of anorectal malformations

The etiology of anorectal malformations (ARM) is complicated because of the spectrum of anomalies seen clinically, many of which are isolated and seemingly unique. Recent studies suggest that ARMs result from abnormal cloacal membrane (CM) development that contributes to disrupt normal local muscle and nerve development. If CM maldevelopment is severe, the rectal pouch lies above the pelvic floor, resulting in asymmetric and/or deviated musculature, so a midline incision is likely to cause trauma or be detrimental. Autonomic nerve plexuses can be associated with a fistula tract in ARMs and are also at risk for damage during surgery and contribute to genitourinary complications. Understanding the anatomy and development of the perineum is crucial for treating the broad spectrum of anomalies associated with ARMs and may assist in predicting/managing other related morbidity.

SOCIODEMOGRAPHIC AND CLINICAL CHARACTERIZATION OF CHILDREN WITH STOMA: AN EPIDEMIOLOGICAL STUDY

Objective: To characterize the epidemiological clinical profile of children with ostomies treated in the outpatient clinic of a reference public teaching hospital for children in Brazil. Method: Descriptive, documentary, retrospective and quantitative study, carried out by extracting sociodemographic and clinical data from electronic medical records of children with ostomies, monitored from 2014 to 2018. The data underwent descriptive statistics, and in the analysis, the data were organized in a spreadsheet in Microsoft Excel version 2010, distributed in three tables, their values represented in absolute and relative frequency. Results: Of the 85 children with ostomy, there was a predominance of males, aged between 1 and 4 years. Anorectal anomaly was considered the main diagnosis. There was a high number of colostomies made. Contact dermatitis was the most frequent peristomal complication. There were difficulties in the routine of families attending the outpatient clinic, and the mother as the main caregiver. Conclusion: The study found relevant aspects related to care planning based on the demand of each child and health education for the prevention of complications, essential actions in the provision of safe and quality nursing care, as well as favoring the operationalization of public policies related to the health of children with ostomies.

CARACTERIZAÇÃO SOCIODEMOGRÁFICA E CLÍNICA DE CRIANÇAS COM ESTOMIA: UM ESTUDO EPIDEMIOLÓGICO

Objetivo:Caracterizar o perfil clínico epidemiológico de crianças com estomia atendidas no ambulatório de um hospital público de ensino de referência na área infantil no Brasil. Método: Estudo descritivo, documental, retrospectivo e de natureza quantitativa, realizado por meio da extração de dados sociodemográficos e clínicos de prontuários eletrônicos de crianças com estomia, acompanhadas de 2014 a 2018. Os dados passaram por estatística descritiva e, na análise, foram organizados em uma planilha no programa Microsoft Excel versão 2010, distribuídas em três tabelas, seus valores representados em frequência absoluta e relativa. Resultados: Das 85 crianças com estomia, houve predominância do sexo masculino, idade entre 1 a 4 anos. Anomalia anorretal foi considerada o principal diagnóstico. Constatou-se elevado número de colostomias confeccionadas. Dermatite de contato foi a complicação periestomal mais frequente. Verificou-se a dificuldade na rotina de comparecimento das famílias ao ambulatório e constatou-se a mãe como cuidadora principal. Conclusão: O estudo concluiu relevantes aspectos relacionados ao planejamento do cuidado pautado na demanda de cada criança e na educação em saúde para a prevenção de complicações, ações indispensáveis na oferta do cuidado de enfermagem seguro e de qualidade, como também favorecer operacionalização das políticas públicas relacionadas à saúde da criança com estomias.

Wnt5a plays a critical role in anal opening in mice at an early stage of embryonic development

PURPOSE

Anorectal malformations are associated with other organ malformations. Proximodistal elongation of the cloacal plate and anal opening at its distal end are essential for anal development. However, the anal developmental stage in which Wnt5a is directly involved remains unelucidated. Here, we attempted to identify this developmental stage; since Wnt5a is expressed in the mesoderm, and the striated muscle complex (SMC) in mice develops from the mesoderm, we also examined Wnt5a contribution to SMC development.

METHODS

We established conditional knockout (CKO) mice in which Wnt5a could be knocked out using an appropriate tamoxifen dose. We evaluated the macroscopic appearance and histopathological features of Wnt5aCKO and wild-type mouse embryos.

RESULTS

Wnt5aCKO mice showed phenotypes typical of Wnt5a constitutional knockout mice when Wnt5a was knocked out at E8-E11. Furthermore, the anus failed to open when Wnt5a was knocked out at E8 but opened when it was knocked out at E9 or thereafter. The caudal end of the SMC was dysplastic in Wnt5aCKO mice induced at E8, but was unaffected when mice were induced at E9 or thereafter.

CONCLUSION

We suggest a critical role for Wnt5a in anal opening and SMC formation at a very early stage of embryonic development.

Congenital anomalies of the tubular gastrointestinal tract

Congenital anomalies of the tubular gastrointestinal tract are an important cause of morbidity not only in infants, but also in children and adults. The gastrointestinal (GI) tract, composed of all three primitive germ layers, develops early during embryogenesis. Two major steps in its development are the formation of the gut tube (giving rise to the foregut, the midgut and the hindgut), and the formation of individual organs with specialized cell types. Formation of an intact and functioning GI tract is under strict control from various molecular pathways. Disruption of any of these crucial mechanisms involved in the cell-fate decision along the dorsoventral, anteroposterior, left-right and radial axes, can lead to numerous congenital anomalies, most of which occur and present in infancy. However, they may run undetected during childhood. Therapy is surgical, which in some cases must be performed urgently, and prognosis depends on early diagnosis and suitable treatment. A precise pathologic macroscopic or microscopic diagnosis is important, not only for the immediate treatment and management of affected individuals, but also for future counselling of the affected individual and their family. This is even more true in cases of multiple anomalies or syndromic patterns. We discuss some of the more frequent or clinically important congenital anomalies of the tubular GI, including atresia's, duplications, intestinal malrotation, Meckel's diverticulum and Hirschsprung's Disease.

Investigation of the risk factors of anorectal malformations

PURPOSE

To investigate the factors that influence the occurrence of anorectal malformations (ARMs).

METHODS

From December 2018 to December 2019, 136 children treated for ARMs at the Children's Hospital of Chongqing Medical University were included in the case group. The control group consisted of children with intussusception or perianal abscesses. A uniform questionnaire was filled by the parents of the enrolled children.

RESULTS

The birth weight of the cases was significantly lower than that of the controls (p < .01), and children with ARMs were more likely to be complicated with single umbilical artery (SUA) (p < .001). Maternal upper respiratory tract infection (adjusted odds ratio [OR_adj ], 2.44; 95% confidence interval [CI], 1.29-4.63) and urogenital infection (OR_adj , 2.67; 95% CI 1.11-6.38) during the first trimester of pregnancy, anemia during pregnancy (OR_adj , 5.69; 95% CI, 1.01-32.07), and exposure to hazardous substances 6 months before pregnancy and during the first trimester of pregnancy (OR_adj , 13.82; 95% CI, 3.86-49.35) are associated with increased risk of ARMs. Folic acid supplements (OR_adj , 0.31; 95% CI, 0.14-0.65) and multivitamin (OR_adj , 0.34; 95% CI, 0.15-0.79) had a protective effect on ARMs. Paternal drug use (OR_adj , 9.17; 95% CI, 2.19-38.49) 6 months before their wives' conception increased the risk of ARMs.

CONCLUSION

Maternal infection, anemia during pregnancy, and maternal hazardous substances exposure are possible risk factors for ARMs. Folic acid supplements and multivitamin can reduce the occurrence of ARMs. Meanwhile, paternal drug use may also be a risk factor for ARMs.

Attention deficit hyperactivity and autism spectrum disorders in patients with anorectal malformations

AIM

To assess the risk of neurodevelopmental disorders in patients with anorectal malformations compared to controls.

METHODS

This was a population-based cohort study including all patients born in Sweden 1997-2012 with anorectal malformation in the Swedish National Patient Register and five matched controls per patient. Anorectal malformation was the exposure. All individuals were evaluated for the outcomes, attention deficit hyperactivity disorder or autism spectrum disorder in the National Patient Register. Data on drugs for attention deficit hyperactivity disorder were retrieved from the Swedish Prescribed Drug Register and used as proxy for attention deficit hyperactivity disorder. Conditional logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (95% CI). Analyses were adjusted for confounders.

RESULTS

Five hundred and fifteen patients with anorectal malformations and 2560 controls were included. Patients with anorectal malformation had a higher risk of attention deficit hyperactivity disorder (OR 3.01 (95% CI, 1.83-4.95)) and autism spectrum disorders (OR 3.07 (95% CI, 1.62-5.79)) compared to the controls. Significantly more patients with anorectal malformation had been prescribed medication for attention deficit hyperactivity disorder compared to controls (OR 2.26 (95% CI 1.33-3.85)).

CONCLUSION

Patients with anorectal malformations have a higher risk of attention deficit hyperactivity disorder and autism spectrum disorders than controls.

RNA-Seq Profiling of Circular RNAs During Development of Hindgut in Rat Embryos With Ethylenethiourea-Induced Anorectal Malformations

Anorectal malformations (ARMs) are among the most common congenital terminal digestive tract malformations. Circular RNAs (circRNAs), a novel type of endogenous non-coding RNAs, play roles in the development of the digestive system; however, their contributions to the pathogenesis of ARMs are not well-established. In this study, we explored the mechanism underlying ethylenethiourea (ETU)-induced ARMs by profiling circRNA expression via RNA-seq and constructing a regulatory circRNA-miRNA-mRNA network. Nine pregnant rats were gavage-fed a single dose of 125 mg/kg 1% ETU (ARM group) on gestational day 10 (GD10), and another 9 pregnant rats received a similar dose of saline (normal group) as a control. Embryos were obtained by cesarean section on the key time-points of anorectal development (GD14, GD15, and GD16). Hindgut samples isolated from the fetuses were evaluated by high-throughput sequencing and differentially expressed circRNAs were validated by reverse transcription-quantitative polymerase chain reaction, agarose gel electrophoresis, and Sanger cloning and sequencing. A total of 18295 circRNAs were identified in the normal and ARM groups. Based on the 425 differentially expressed circRNAs (|Fc| > 2, p < 0.05), circRNA-miRNA and miRNA-mRNA pairs were predicted using miREAP, miRanda, and TargetScan. A total of 55 circRNAs (14 up- and 41 downregulated in the ARM group compared to the normal group) were predicted to bind to 195 miRNAs and 947 mRNAs. Competing endogenous RNA networks and a Kyoto Encyclopedia of Genes and Genomes analysis revealed that novel_circ_001042 had the greatest connectivity and was closely related to ARM-associated signaling pathways, such as the Wingless Type MMTV integration site family, mitogen-activated protein kinase, and transforming growth factor-β pathways. These results provide original insight into the roles of circRNAs in ARMs and provide a valuable resource for further analyses of molecular mechanisms and signaling networks.

Upregulation of PPPDE1 contributes to anorectal malformations via the mitochondrial apoptosis pathway during hindgut development in rats

Congenital anorectal malformations (ARMs) are among the most prominent deformities of the gastrointestinal tract; however, their precise aetiology remains obscure. Immunohistochemistry demonstrated that, in the ARM group, the PPPDE1-positive cells were widely distributed in the hindgut epithelial tissue from GD13 to GD16. Immunofluorescence revealed that most TUNEL-, Bax-, and Cytochrome C (Cyt C)-positive cells overlapped with PPPDE1-positive cells in the urorectal septum (URS). Western blotting and quantitative real-time RT-PCR revealed that PPPDE1 levels were significantly higher in the ARM group from GD13 to GD14 (p < 0.05). IEC-6 cells were transfected with PPPDE1 overexpression plasmid/NC (negative control) or si-PPPDE1/si-NC. Flow cytometry analysis and CCK-8 assay (used to detect apoptosis and proliferation, respectively), as well as western blotting, showed that the levels of PPPDE1 were positively correlated with the pro-apoptotic molecules Bax and Cyt C. Accordingly, aberrantly high expression of PPPDE1 caused a spatiotemporal imbalance in foetal rats with ARMs during hindgut development. Therefore, the upregulation of PPPDE1 may promote epithelial apoptosis and reduce proliferation in the hindgut via the mitochondrial apoptotic pathway. This could affect the fusion of the URS and cloacal membrane, ultimately inhibiting the hindgut development and resulting in ARMs.

Bioinformatics analysis of candidate genes involved in ethanol-induced microtia pathogenesis based on a human genome database: GeneCards

OBJECTIVE

Ethanol used by women during pregnancy increases the risk for microtia in the foetus. Traditionally, laboratory experiments and Mouse Genome Informatics (MGI) have been used to explore microtia pathogenesis. The aim of this study was to screen and verify hub genes involved in ethanol-induced microtia and to explore the potential molecular mechanisms.

METHODS

Overlapping genes related to ethanol and microtia were acquired from the GeneCards database and filtered by confidence score. These genes were further analysed via bioinformatics. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis results were visualized with the clusterProfiler R package. A protein-protein interaction (PPI) network was constructed based on data from the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database.

RESULTS

Overall, 41 genes related to both ethanol and microtia were identified. The genes most relevant to ethanol-induced microtia pathogenesis included FGFR-2, FGFR-3, FGF-8, TP53, IGF1, SHH, CTNNB1, and PAX6, among others. Most genes were strongly enriched for tissue and organ development in GO analysis. Additionally, many genes were enriched in the Ras, FoxO, MAPK, and PI3K-Akt signalling pathways in KEGG analysis.

CONCLUSIONS

Bioinformatics analysis was conducted on genes currently known to be related to ethanol-induced microtia pathogenesis. We propose that mechanisms involving FGF-family genes, TP53, IGF1 and SHH contribute significantly to ethanol-induced microtia and the accompanying malformation of other structures.

[Anorectal malformations: a 6-years review at the University Clinics of Lubumbashi]

Les malformations anorectales (MAR) sont des dysgénésies de la filière anogénitale comprenant plusieurs variétés anatomopathologiques. Leur diagnostic précoce permet une prise en charge précoce, laquelle réduit la morbi-mortalité y associée, surtout dans les pays en développement. L´objectif de cette étude est d´analyser les aspects épidémio-cliniques, thérapeutiques et évolutifs des malformations anorectales (MAR) aux Cliniques Universitaires de Lubumbashi. Il s´agit d´une étude descriptive transversale, ayant concerné 24 patients de 0 à 1 an admis dans notre service pour MAR. Sont exclus para cliniques dans notre série, les patients âgés de plus d'une année et non porteurs des examens demandés. Les données ont été recueillies sur base d´une fiche d´enquête reprenant les différents paramètres: l´âge au moment de la consultation, le sexe, le poids de naissance, la circonstance de découverte, la variété anatomique, le type de traitement et évolution des malades. La fréquence était de 24 cas (20,68%) des MAR sur 116 cas des malformations congénitales. L´âge médian était de 2 jours, le sexe-ratio de 1/3 en faveur des filles. L´occlusion intestinale était le diagnostic à l´admission le plus fréquent (50%). Les MAR basses étaient les plus fréquentes (11 patients soit 45,7%) dont 10 sans fistule. L´atrésie intestinale a été la malformation associée la plus fréquente (3 patients). L´anoplastie par abaissement abdomino-périnéal couplée aux dilatations anales postopératoires a été faite chez 13 patients, soit dans 54,1% des cas. Six patients sont décédés de causes inconnues et 6 autres ont été perdus de vues. Pour le résultat fonctionnel, sur les 12 des 24 patients pris en charge qui se sont présentés à la réévaluation 3 mois après sortie de l´hôpital, 3 d´entre eux ont présenté des signes d´incontinence, et 9 d´entre eux étaient continents parmi lesquels 8 étaient diagnostiqués avec MAR basse et 1 avec MAR haute. Les MAR sont une réalité dans notre milieu, cependant, le diagnostic n´est majoritairement posé qu´au décours des occlusions intestinales. Le taux des décès reste élevé et des mesures devrait être prises pour permettre des évaluations à long terme, lesquelles sont encore difficiles à faire vu le nombre des perdus de vue.

Biomarker discovery for predicting spontaneous preterm birth from gene expression data by regularized logistic regression

In this work, we provide a computational method of regularized logistic regression for discovering biomarkers of spontaneous preterm birth (SPTB) from gene expression data. The successful identification of SPTB biomarkers will greatly benefit the interference of infant gestational age for reducing the risks of pregnant women and preemies. In recent years, various approaches have been proposed for the feature selection of identifying the subset of meaningful genes that can achieve accurate classification for disease samples from controls. Here, we comprehensively summarize the regularized logistic regression with seven effective penalties developed for the selection of strongly indicative genes of SPTB from microarray data. We compare their properties and assess their classification performances in multiple datasets. It shows that elastic net, lasso,L 1 / 2 and SCAD penalties get the better performance than others and can be successfully used to identify biomarkers of SPTB. Particularly, we make a functional enrichment analysis on these biomarkers and construct a logistic regression classifier based on them. The classifier generates an indicator of preterm risk score (PRS) for predicting SPTB. Based on the trained predictor, we verify the identified biomarkers on an independent dataset. The biomarkers achieve the AUC value of 0.933 in the SPTB classification. The results demonstrate the effectiveness and efficiency of the built-up strategy of biomarker discovery with regularized logistic regression. Obviously, the proposed method of discovering biomarkers for SPTB can be easily extended for other complex diseases.

Folic acid rescues all-trans retinoic acid-induced anorectal malformations in rats

BACKGROUND

To investigate whether folic acid (FA) can rescue anorectal malformations (ARMs) induced by all-trans retinoic acid (ATRA) in rats.

METHODS

Pregnant Sprague-Dawley rats were randomly divided into three groups. In the model group, rats were administered ATRA (110 mg/kg) by gavage on the 10th day of gestation (E10.5). Rats in the rescue group were administered FA (40 mg/kg) by gavage 0.5 and 12 hr after treatment with ATRA. All fetuses were harvested on E20.5 using cesarean section and examined for ARMs. We recorded the weight, body length, tail length, and associated malformations of all the embryos. Hematoxylin and eosin staining was used to analyze the histopathology of the fetuses.

RESULTS

Control rats did not show any abnormalities. ARMs, tail deformities (less than half of normal length), and neural tube defects were found in 97.98% (97/99), 92.93% (92/99), and 32.32% (32/99) of the rats in the model group, respectively. The incidence of ARMs and tail deformities were 48.57% (51/105) and 35.24% (37/105), respectively, in the rescue rats; no neural tube defects were observed in these rats. The weight, body length, and tail length of the fetal rats in the rescue group were more than those in the model group, but less than those in the control group.

CONCLUSION

Taken together, FA rescued ARMs induced by ATRA in rats. Thus, FA may reduce the incidence of associated malformations and improve the growth and development of fetal rats.

Relationship Between Quality of Life and Social Support in Parents of Children with Congenital Anorectal Malformations in China

PURPOSE

This study aimed to explore the quality of life (QOL) and social support of parents of children with congenital anorectal malformation (ARM), and to examine the relationship between them.

DESIGN AND METHODS

A cross-sectional study was conducted at Anhui Provincial Children's Hospital of China from January to June of 2018. A total of 108 parents participated in this survey. QOL and social support were accessed using the short version of the World Health Organization's Quality of Life Instrument (WHOQOL-BREF) and the Social Support Rate Scale (SSRS), respectively. Analyses were performed with multivariate linear regression and canonical correlation.

RESULTS

The parents' scores in the physical, psychological, and environmental domains were lower than those in the general population in China. Gender, monthly income, combined malformation, objective support, subjective support and utilization of support were the major influencing factors of QOL. A canonical correlation analysis indicated social support was positively correlated with QOL, and subjective support, psychological domain had the largest standardized factor loading in social support and QOL.

CONCLUSIONS

The QOL of parents of ARM patients was not optimistic. More attention needs to be paid to increasing social support for the parents of ARM to enhance their QOL.

PRACTICE IMPLICATIONS

For government, increasing funds and resources to invest in the establishment and improvement of the social support network is necessary. For doctors and nurses, providing better medical and psychological services to patients and their parents is essential.

Comparison of Maternal Histories and Exposures in Children With Isolated Anorectal Malformation Versus Anorectal Malformation With Genitourinary Anomalies

Introduction

To our knowledge, there are no studies to date that have compared patients with isolated anorectal malformation (ARM) to patients with ARM and an associated genitourinary (GU) malformation despite a possible etiological difference between these two entities. We examined the differences in maternal and prenatal exposures and comorbidities between patients with isolated ARM and patients with ARM and associated GU malformations.

Materials and methods

A retrospective cohort study of children with ARM, enrolled in the Pediatric Colorectal and Pelvic Learning Consortium (PCPLC) between February 2017 and October 2019, was performed comparing those with isolated ARM to those with ARM and associated GU anomalies (GU +/- additional anomalies) as well as to those with ARM and a GU anomaly with no anomaly of any other system (GU-only). We compared the prevalence of prematurity, family history of colorectal disorders, as well as maternal and prenatal comorbidities and exposures between these two cohorts and the isolated ARM cohort.

Results

A total of 505 patients (117 with isolated ARM and 388 with ARM and associated GU anomalies) were enrolled. Of the 388 patients with ARM and associated GU anomalies, 48 had an ARM with a GU anomaly without an anomaly in any other system. There was an increased prevalence of premature births in the GU +/- additional anomalies cohort compared to the isolated ARM cohort (27 vs 14%, p=0.003). This difference was not seen in the GU-only cohort. There was no difference between the cohorts regarding prevalence of family history of ARM or maternal and prenatal comorbidities or exposures.

Conclusions

Patients with an ARM and an associated GU anomaly with or without other congenital anomalies are more likely to be born prematurely compared to patients with an isolated ARM. Parents of these children should be counseled on this increased risk.

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 HumanExome 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.

Integrative analysis of microRNA and mRNA expression profiles in fetal rat model with anorectal malformation

Background

Anorectal malformations (ARMs) are the most common congenital malformation of the gut, and regulated by multiple signal transduction pathways. The microRNA (miRNA) expression profiles and their biologial functions in anorectal malformations (ARMs) remain unclear. The aim of our study was to evaluate miRNA and mRNA expression profiles in the ARM rats.

Methods and Materials

ARM was induced with ethylenethiourea (ETU) on gestational day 10. Cesarean deliveries were performed to harvest the embryos on gestional day 20. For the extraction of total RNA, 1 cm terminal hindgut samples were obtained from three fetal rats that had similar weights. The microarrays and quantitative RT-PCR analysis were conducted to evaluate the miRNA and mRNA expression profiles in normal fetal rats (n = 3) and ARM fetal rats (n = 3).

Results

In total, 33 miRNAs and 772 mRNAs were significantly and differentially expressed in terminal hindgut tissues of ARM group versus control group. Functional annotation was performed to understand the functions and pathways of differentially expressed mRNAs. Also, we constructed a miRNA-target gene regulatory network including 25 differentially expressed miRNAs and 76 mRNAs. Furthermore, the credibility of the microarray-based results were validated by using qRT-PCR.

Conclusion

The miRNA and mRNA expression in terminal hindgut tissue of ARM fetal rats might provide a basis for further research on the pathogenesis of ARMs.

Clinical characteristics, prognosis, and its risk factors of anorectal malformations: a retrospective study of 332 cases in Anhui Province of China

Objective: To analyze the clinical characteristics and prognosis of anorectal malformations (ARMs) and explore the influencing factors of postoperative anal function in Anhui Province of China.Methods: We performed a retrospective study of ARM patients diagnosed from 2013 to 2016 at Anhui Provincial Children's Hospital. A total of 332 infants with ARM were enrolled in the survey. Demographic characteristic and clinical data were collected. Follow-up study was required to evaluate anal function after the operation and Logistic regression analysis was used for analyzing the influencing factors of prognosis.Results: A total of 253 males and 79 females were studied, with a ratio of 3.2:1. Abdominal distention was the most common presenting symptom, followed by vomiting. Of the cases, 53.0% (176/332) combined with other congenital malformations. The incidence of other malformations in intermediate and high ARM group was significantly higher than that in the low ARM group. Of the cases, 280 underwent anoplasty. 188, 73, 19 cases were treated with one-stage perineal anoplasty, posterior sagittal anorectoplasty, laparoscopically assisted anorectal pull-through, respectively. The result of follow-up study showed that the excellent and good rate of postoperative anal function was up to 83.3%. Type of ARM, combined with other malformations and the times of anoplasty were related to the anal function postoperatively.Conclusions: ARM occurs mainly in male infants. The incidence of associated abnormalities in ARM patients was high. Intermediate- and high-type, combined with other malformations and more times of anoplasty increased the risk of anal dysfunction postoperatively. Multicenter, prospective randomized-controlled studies were needed to clarify the curative effect of different surgical approaches.

Integrating lncRNAs and mRNAs expression profiles in terminal hindgut of fetal rats with anorectal malformations

BACKGROUND

The detailed embryonic etiology and pathogenesis of anorectal malformations (ARMs) remains unclear. Recent studies have shown that gene expression abnormalities were the key factors that result in ARMs. Long non-coding RNAs (lncRNAs) were reported as the 'transcriptional noise' within the genome. The expression profiles of lncRNA and mRNA remain less characterized in the pathogenesis of ARMs. Furthermore, the function of lncRNAs in the regulation of this process has not been investigated so far. Therefore, this current study was aimed to integrate lncRNA and mRNA expression profiles in terminal hindgut of ethylenethiourea (ETU)-induced ARM rats using Agilents lncRNA and mRNA co-expression microarrays.

METHODS

ARM model was induced with ethylenethiourea (ETU) on gestational day 10. Cesarean deliveries were conducted to collect the embryos on gestational day 20. For the extraction of total RNA, 1-cm terminal hindgut tissues were collected from three fetal rats with similair weights. The microarrays and quantitative RT-PCR analysis were conducted to evaluate the lncRNA and mRNA expression profiles in normal fetal rats and ARM fetal rats.

RESULTS

Compared with control group, 164 lncRNAs were observed to be aberrantly expressed (FC ≥ 2; P < 0.05) in ARM group, including 36 upregulated and 128 downregulated, while 772 mRNAs were observed to be aberrantly expressed (FC ≥ 2; P < 0.05) in the terminal hindgut, including 350 up-regulated and 422 down-regulated. The differential expression profiles between the ARM and the control group were used for gene ontology (GO) and pathway analysis. A subset of those RNAs was identified to be closely related to the development process of ARMs. The four RNAs that were differentially expressed between the two groups were selected for qPCR validation, and the results were in line with the microarray data. In addition, the lncRNAs and mRNA co-expression network was established according to the correlation analysis. We predicted the functions of transregulatory lncRNAs by the TFs (transcription factors) which might modulate their expression. In the core network of lncRNA-TF pairs, the lncRNAs can be classified into 5 categories of pathways governed by Jun, c-Myc, Usf1, Alf2, and Stat3.

CONCLUSION

From the above results, it can be suggested that these aberrant lncRNAs might participate in the pathogenesis of ARM, and our present work may provide new research directions for future studies of ARMs.