Physical, language, neurodevelopment and phenotype-genotype correlation of Chinese patients with Mowat-Wilson syndrome

Clinical Characteristics and Postoperative Functional Outcomes in Children With Mowat-Wilson Syndrome and Hirschsprung's Disease: A Single-center Study

BACKGROUND

Mowat-Wilson Syndrome (MWS) is a rare autosomal dominant genetic disorder. Approximately half of individuals with MWS present with Hirschsprung's Disease (HSCR). There is no nested case-control study that correlates with its prognosis. This study aimed to compare the mid-to-short-term postoperative prognosis between children with MWS-associated with HSCR and those with isolated HSCR.

METHODS

A retrospective analysis was conducted on clinical data of HSCR patients who underwent surgery at a pediatric hospital from January 2016 to June 2023. Patients with MWS-associated HSCR were identified through confirmed mutations in the ZEB2 gene. Propensity score matching (PSM) was used for comparative analysis.

RESULTS

Among the identified cases, 11 had MWS-associated HSCR, and 1088 had isolated HSCR, with 44 HSCR-alone patients included in the control group after PSM. The case group comprised 7 males and 4 females, with a median age of 4 years and a median age at surgery of 3.96 months (IQR, 2.04-8.52). The study found no significant difference in the incidence of postoperative Hirschsprung-associated enterocolitis (HAEC) between the two groups, although severe abdominal distension symptoms were more prevalent in the case group. However, the median period of recurrent HAEC from the first to the last occurrence in the case group was longer at 18 months (IQR, 3-30) compared to 0 months (IQR, 0-6) in the control group. Additionally, the case group exhibited a higher rate of constipation and significantly poorer bowel function compared to the control group. Other mid-to-short-term complication rates were comparable between the two groups.

CONCLUSIONS

Children with MWS-associated HSCR face greater challenges in postoperative recovery, including a longer period of recurrent HAEC, more severe constipation, and poorer bowel function, highlighting the need for focused prevention and enhanced intestinal management in this patient population.

Peter C, Lovell S, Rafi SK, Butler MG. ZEB2 Gene Pathogenic Variants Across Protein-Coding Regions and Impact on Clinical Manifestations: A Review

Mowat-Wilson syndrome (MWS) is a rare multi-system genetic disorder caused by variants in the Zinc Finger E-Box-Binding Homeobox 2 (ZEB2) gene. ZEB2 is an autosomal dominant gene containing ten exons within the canonical version transcript (Isoform: O60315-1). The ZEB2 gene encodes six functional domains and seven non-domain regions. This review provides a comprehensive summary of pathogenic variants and their associated MWS clinical characteristics, focusing on ZEB2 pathogenic variants, functional protein domains and non-domain regions with clinical features. A systematic literature search from 2001 to 2023 and of unpublished datasets found 191 individuals with reported clinical features and genotypic data. Genetic defects and clinical manifestations were examined that presumably impact on the structure and function of the ZEB2 gene, thereby causing multiple developmental defects with corresponding clinical presentation. This study found more nonsense ZEB2 variants observed within exon 8, which encodes four of the six protein domains: the CtBP-interacting domain (CID), homeodomain (HD), SMAD-binding domain (SMD or SBD) and part of the N-terminal zinc finger cluster (N-ZF), suggesting exon 8 plays a crucial role in this protein structure and function with multi-organ involvement. Exon 8 defects were found to be statistically more represented for gastrointestinal findings when compared to other exons, while frameshift defects were more often seen for the typical MWS face in non-domain protein regions. In contrast, nonsense or other types of variants in exons 3, 4 and 5 which encode only flanking non-domain regions were observed more often, compared with other exons excluding exon 8, to be specifically involved in the MWS facial gestalt, brain malformations, developmental delay and intellectual disability. Deleterious ZEB2 frameshift (45%) and nonsense (38%) gene variants were most often observed with deletions at 6% and missense at 5%. The genotype and clinical relationships in MWS can provide insights into prognosis, morbidity, clinical surveillance strategies and counseling of family members.

Quantifying attention in children with intellectual and developmental disabilities through multicenter electrooculogram signal analysis

In a multicenter case-control investigation, we assessed the efficacy of the Electrooculogram Signal Analysis (EOG-SA) method, which integrates attention-related visual evocation, electrooculography, and nonlinear analysis, for distinguishing between intellectual and developmental disabilities (IDD) and typical development (TD) in children. Analyzing 127 participants (63 IDD, 64 TD), we applied nonlinear dynamics for feature extraction. Results indicated EOG-SA's capability to distinguish IDD, with higher template thresholds and Correlation Dimension values correlating with clinical severity. The template threshold proved a robust indicator, with higher values denoting severe IDD. Discriminative metrics showed areas under the curve of 0.91 (template threshold) and 0.85/0.91 (D2), with sensitivities and specificities of 77.6%/95.9% and 93.5%/71.0%, respectively. EOG-SA emerges as a promising tool, offering interpretable neural biomarkers for early and nuanced diagnosis of IDD.

Mowat-Wilson Syndrome: Case Report and Review of ZEB2 Gene Variant Types, Protein Defects and Molecular Interactions

Mowat-Wilson syndrome (MWS) is a rare genetic neurodevelopmental congenital disorder associated with various defects of the zinc finger E-box binding homeobox 2 (ZEB2) gene. The ZEB2 gene is autosomal dominant and encodes six protein domains including the SMAD-binding protein, which functions as a transcriptional corepressor involved in the conversion of neuroepithelial cells in early brain development and as a mediator of trophoblast differentiation. This review summarizes reported ZEB2 gene variants, their types, and frequencies among the 10 exons of ZEB2. Additionally, we summarized their corresponding encoded protein defects including the most common variant, c.2083 C>T in exon 8, which directly impacts the homeodomain (HD) protein domain. This single defect was found in 11% of the 298 reported patients with MWS. This review demonstrates that exon 8 encodes at least three of the six protein domains and accounts for 66% (198/298) of the variants identified. More than 90% of the defects were due to nonsense or frameshift changes. We show examples of protein modeling changes that occurred as a result of ZEB2 gene defects. We also report a novel pathogenic variant in exon 8 in a 5-year-old female proband with MWS. This review further explores other genes predicted to be interacting with the ZEB2 gene and their predicted gene-gene molecular interactions with protein binding effects on embryonic multi-system development such as craniofacial, spine, brain, kidney, cardiovascular, and hematopoiesis.

Transcriptome analyses of murine right and left maxilla-mandibular complex

OBJECTIVE

The objective of the study was to investigate differential gene expression between murine right and left maxilla-mandibular (MxMn) complexes.

SETTING AND SAMPLE POPULATION

Wild-type (WT) C57BL/6 embryonic (E) day 14.5 (n = 3) and 18.5 (n = 3) murine embryos.

METHODS

The E14.5 and 18.5 embryos were harvested and hemi-sectioned the MxMn complexes into right and left halves in the mid-sagittal plane. We isolated total RNA using Trizol reagent and further purified using the RNA-easy kit (QIAGEN). We confirmed equal expression of house-keeping genes in right and left halves using RT-PCR and then performed paired-end whole mRNA sequencing in LC Sciences (Houston, TX) followed by differential transcript analyses (>1 or <-1 log fold change; p < .05; q < .05; and FPKM >0.5 in 2/3 samples). The Mouse Genome Informatics and Online Mendelian Inheritance in Man databases as well as gnomAD constraint scores were used to prioritize differentially expressed transcripts.

RESULTS

There were 19 upregulated and 19 downregulated transcripts at E14.5 and 8 upregulated and 17 downregulated transcripts at E18.5 time-points. These differentially expressed transcripts were statistically significant and shown to be associated with craniofacial phenotypes in mouse models. These transcripts also have significant gnomAD constraint scores and are enriched in biological processes critical for embryogenesis.

CONCLUSIONS

We identified significant differential expression of transcripts between E14.5 and 18.5 murine right and left MxMn complexes. These findings when extrapolated to humans, they may provide a biological basis for facial asymmetry. Further experiments are required to validate these findings in murine models with craniofacial asymmetry.