Mowat-Wilson syndrome: the first report of an association with central nervous system tumors

Bioinformatics Prediction for Network-Based Integrative Multi-Omics Expression Data Analysis in Hirschsprung Disease

Hirschsprung's disease (HSCR) is a rare developmental disorder in which enteric ganglia are missing along a portion of the intestine. HSCR has a complex inheritance, with RET as the major disease-causing gene. However, the pathogenesis of HSCR is still not completely understood. Therefore, we applied a computational approach based on multi-omics network characterization and clustering analysis for HSCR-related gene/miRNA identification and biomarker discovery. Protein-protein interaction (PPI) and miRNA-target interaction (MTI) networks were analyzed by DPClusO and BiClusO, respectively, and finally, the biomarker potential of miRNAs was computationally screened by miRNA-BD. In this study, a total of 55 significant gene-disease modules were identified, allowing us to propose 178 new HSCR candidate genes and two biological pathways. Moreover, we identified 12 key miRNAs with biomarker potential among 137 predicted HSCR-associated miRNAs. Functional analysis of new candidates showed that enrichment terms related to gene ontology (GO) and pathways were associated with HSCR. In conclusion, this approach has allowed us to decipher new clues of the etiopathogenesis of HSCR, although molecular experiments are further needed for clinical validations.

Neurological Phenotype of Mowat-Wilson Syndrome

Mowat-Wilson Syndrome (MWS) (OMIM # 235730) is a rare disorder due to ZEB2 gene defects (heterozygous mutation or deletion). The ZEB2 gene is a widely expressed regulatory gene, extremely important for the proper prenatal development. MWS is characterized by a specific facial gestalt and multiple musculoskeletal, cardiac, gastrointestinal, and urogenital anomalies. The nervous system involvement is extensive and constitutes one of the main features in MWS, heavily affecting prognosis and life quality of affected individuals. This review aims to comprehensively organize and discuss the neurological and neurodevelopmental phenotype of MWS. First, we will describe the role of ZEB2 in the formation and development of the nervous system by reviewing the preclinical studies in this regard. ZEB2 regulates the neural crest cell differentiation and migration, as well as in the modulation of GABAergic transmission. This leads to different degrees of structural and functional impairment that have been explored and deepened by various authors over the years. Subsequently, the different neurological aspects of MWS (head and brain malformations, epilepsy, sleep disorders, and enteric and peripheral nervous system involvement, as well as developmental, cognitive, and behavioral features) will be faced one at a time and extensively examined from both a clinical and etiopathogenetic point of view, linking them to the ZEB2 related pathways.

Clinical characteristics of Polish patients with molecularly confirmed Mowat-Wilson syndrome

Mowat-Wilson syndrome is a rare neurodevelopmental disorder caused by pathogenic variants in the ZEB2 gene, intragenic deletions of the ZEB2 gene, and microdeletions in the critical chromosomal region 2q22-23, where the ZEB2 gene is located. Mowat-Wilson syndrome is characterized by typical facial features that change with the age, severe developmental delay with intellectual disability, and multiple congenital abnormalities. The authors describe the clinical and genetic aspects of 28th patients with Mowat-Wilson syndrome diagnosed in Poland. Characteristic dysmorphic features, psychomotor retardation, intellectual disability, and congenital anomalies were present in all cases. The incidence of most common congenital anomalies (heart defect, Hirschsprung disease, brain defects) was similar to presented in literature. Epilepsy was less common compared to previously reported cases. Although the spectrum of disorders in patients with Mowat-Wilson syndrome is wide, knowledge of characteristic dysmorphic features awareness of accompanying abnormalities, especially intellectual disability, improves detection of the syndrome.

Neuroimaging findings in Mowat-Wilson syndrome: a study of 54 patients

PURPOSE

Mowat-Wilson syndrome (MWS) is a genetic disease characterized by distinctive facial features, moderate to severe intellectual disability, and congenital malformations, including Hirschsprung disease, genital and eye anomalies, and congenital heart defects, caused by haploinsufficiency of the ZEB2 gene. To date, no characteristic pattern of brain dysmorphology in MWS has been defined.

METHODS

Through brain magnetic resonance imaging (MRI) analysis, we delineated a neuroimaging phenotype in 54 MWS patients with a proven ZEB2 defect, compared it with the features identified in a thorough review of published cases, and evaluated genotype-phenotype correlations.

RESULTS

Ninety-six percent of patients had abnormal MRI results. The most common features were anomalies of corpus callosum (79.6% of cases), hippocampal abnormalities (77.8%), enlargement of cerebral ventricles (68.5%), and white matter abnormalities (reduction of thickness 40.7%, localized signal alterations 22.2%). Other consistent findings were large basal ganglia, cortical, and cerebellar malformations. Most features were underrepresented in the literature. We also found ZEB2 variations leading to synthesis of a defective protein to be favorable for psychomotor development and some epilepsy features but also associated with corpus callosum agenesis.

CONCLUSION

This study delineated the spectrum of brain anomalies in MWS and provided new insights into the role of ZEB2 in neurodevelopment.Genet Med advance online publication 10 November 2016.

Metastatic Group 3 Medulloblastoma in a Patient With Tuberous Sclerosis Complex: Case Description and Molecular Characterization of the Tumor

Medulloblastoma is the most common pediatric brain tumor. We describe a child with tuberous sclerosis complex that developed a Group 3, myc overexpressed, metastatic medulloblastoma (MB). Considering the high risk of treatment-induced malignancies, a tailored therapy, omitting radiation, was given. Based on the evidence of mammalian target of rapamycin mTORC, mTOR Complex; RAS, Rat sarcoma; RAF, rapidly accelerated fibrosarcoma (mTOR) pathway activation in the tumor, targeted therapy was applied resulting in complete remission of disease. Although the PI3K/AKT/mTOR signaling pathway plays a role in MB, we did not find TSC1/TSC2 (TSC, tuberous sclerosis complex) mutation in our patient. We speculate that a different pathway resulting in mTOR activation is the basis of both TSC and MB in this child; H&E, haematoxilin and eosin; Gd, gadolinium.

Novel Zeb2 gene variation in the Mowat Wilson syndrome (MWS)

BACKGROUND

Mowat Wilson syndrome (MWS) is an uncommon association of Hirschsprung's disease (HSCR). Phenotypic features may develop with time, causing initial difficulties in diagnosis. MWS results from haploinsufficiency of the Zinc finger E-box-binding homeobox 2 (ZEB2) gene, and molecular diagnosis of ZEB2 mutation is required to confirm the diagnosis. We report the first confirmed cases of MWS in three children with the typical facial features, mental retardation, absent corpus callosum, epilepsy, and HSCR and novel Zeb2 variations on DNA analysis.

METHODOLOGY

Clinical features were monitored. DNA extracted from peripheral blood was subjected to bidirectional sequencing analysis following PCR DNA amplification. ZEB2 gene results were compared to the ZEB2 reference sequence (ENS00000169554) for variation. Bioinformatic investigation of novel gene variants was via the "Blastx" program function available via the National Center for Biotechnology Information (http://www.bioinfo.org/NPInter/blast/blast_link.cgi).

RESULTS

Clinical follow-up showed that the phenotypic features were not all present at birth but developed with time in 2 surviving patients. Several Zeb2 variations were detected in the promoter region of the ZEB2 gene of which 2 were novel (-56A/T 1174 11A/12A). In addition, a novel heterozygous single nucleotide insertion in exon 2 of ZEB2 in one patient results in a frameshift causing deletion of the first 8 amino acids of the ZEB2 protein and an alteration of amino acids 9 (G9A), 11 (R11G), and 12 (C12A). In the third patient, a novel single nucleotide deletion exon 8 (1784delC Het) results in a frameshift at amino acid 595 of translated protein. This shortens protein from 1214 to 594 amino acids and affects the functionality of the critical ZEB2 protein.

CONCLUSIONS

MWS is an important link to recognise clinically. It underlines the functionality of the Zeb2 gene in certain syndromic Hirschsprung's disease. These variations probably contribute to the clinical features of the Mowat Wilson phenotype in Hirschsprung's disease but should be confirmed in further research.

Hirschsprung's disease in children with Mowat-Wilson syndrome

BACKGROUND

Hirschsprung's disease (HSCR) is cited as a classical component in the constellation of features found in children with Mowat-Wilson syndrome (MWS), which is caused by a mutation of the ZEB2 gene. The prevalence and phenotype of HSCR in those with MWS has yet to be determined. Similarly, it is not known if children with MWS who undergo a curative pull-through operation experience similar functional outcomes. We aimed to delineate the clinical features of those with MWS and HSCR and to determine if these patients experience unfavourable outcomes following pull-through surgery.

METHODS

A systematic review of the literature using the key search term "Mowat Wilson" was performed using three online databases. Clinical data were collected on all patients with a diagnosis of MWS confirmed by ZEB2 analysis. Data regarding bowel function in children with biopsy-proven HSCR were recorded where available. Statistical analysis was performed using SPSS (v. 20.0).

RESULTS

Fifty-two articles were reviewed in the final analysis, incorporating data on 256 patients with a diagnosis of MWS. HSCR was diagnosed in 111 patients (43.4%). Males with HSCR had a slightly increased risk of genital tract anomalies (e.g. hypospadias) compared to those without HSCR (RR 1.79, p = 0.05). Data pertaining to disease phenotype and functional outcome were only available on 42 and 13 patients, respectively. Rectosigmoid aganglionosis was the most common sub-type of HSCR, being described 26 patients (66.7%), albeit accounting for a lower proportion than would normally be expected in an HSCR population. Only two patients (15.4%) were described as having normal bowel function at follow-up with the remainder having terminal stomas, or experiencing troublesome persistent bowel symptoms and recurrent enterocolitis.

CONCLUSION

Hirschsprung's disease is present in approximately 45% of patients diagnosed with MWS. Although there is a relative lack of data available on the clinical phenotype of HSCR in this group and their functional outcome following pull-through operation, our data suggest an increased prevalence of long-segment aganglionosis and an increased risk of clinically significant persistent bowel symptoms following pull-through surgery, in many cases necessitating terminal stoma formation.

ZEB2 gene mutation and duplication of 22q11.23 in Mowat-Wilson syndrome

Mowat-Wilson syndrome is a recently delineated multiple congenital anomaly syndrome characterized by a distinctive facial appearance in association with intellectual disability, microcephaly, agenesis of the corpus callosum, seizures, congenital heart disease, Hirschsprung disease, short stature, and genitourinary anomalies. We report a 2-year-10-month-old white female with this syndrome caused by mutations in the ZEB2 gene, and in addition a duplication of the 22q11.23, a previously undocumented occurrence.

Mowat-Wilson syndrome: neurological and molecular study in seven patients

OBJECTIVE

To present a seven-cases serie of Mowat-Wilson syndrome (MWS).

METHOD

All patients with positive mutation for the ZEB2 were evaluated by a geneticist and a neurologist, with clinical and laboratorial characterization.

RESULTS

A peculiar facies and mental retardation were present in all patients. The Denver II scale showed intense delay in all aspects, especially fine motor and adaptive. Acquired microcephaly was observed in five patients. Only one patient did not present epilepsy. Epilepsy was focal and predominating in sleep, with status epilepticus in three patients. The initial seizure was associated with fever in most patients (4/6). The EEG showed epileptic focal activity (5/7). The imaging studies revealed total agenesis (4/7) and partial agenesis of the corpus callosum (1/7).

CONCLUSION

Physicians who care for patients with mental retardation and epilepsy should be aware of SMW.