Hirschsprung's disease in children with Mowat-Wilson syndrome

Commentary - Mowat-Wilson Syndrome in Hirschsprung: Something Special or Just a Generic Problem?

The author comments on the recent paper by Cheng et al describing a series of MWS patients derived from a much larger series of HSCR patients. Children operated for HSCR with developmental delay suffer more difficulties than children without, but the literature varies on the outcomes associated with developmental delay such as Down syndrome and MWS. The author suggests that the degree of developmental delay has a bearing on outcome, and he further asks whether MWS has any particular features to make its prognosis different from other developmental delay syndromes associated with HSCR.

Mowat-Wilson syndrome: Case report

BACKGROUND

Mowat-Wilson syndrome (MWS) is a rare genetic condition resulting in multiple congenital anomalies, including facial dysmorphism, structural anomalies of the internal organs, functional disorders, and, although less commonly, ocular abnormalities. To present a child with MWS and eye abnormalities.

METHODS

A 3-year-old boy was born at 37 weeks of pregnancy with dysmorphic features, neurodevelopmental disorders, genetically confirmed MWS, nystagmus, strabismus, and suspicion of congenital glaucoma. Ophthalmic examination was carried out under general anesthesia; eyeball ultrasound and electrophysiological examination (flash visual evoked potentials) were also performed.

RESULTS

The examinations revealed nystagmus, a normal response of pupils to light in both eyes, and normal intraocular pressure, that is, 17 and 18 mm Hg in the right and left eye, respectively. Corneal thickness was 606 µm in the right eye and 588 µm in the left eye. Gonioscopy revealed displacement of Schwalbe line anterior to the limbus of the cornea (posterior embryotoxon). Fundus examination revealed a pink optic disk with a cup-to-disc ratio of 0.5, macular pigment regrouping, and normal blood vessels. Flash visual evoked potentials: P2 latency was normal. P2 amplitude from the left hemisphere was reduced to 50%, and P2 amplitude over the right hemisphere was normal.

CONCLUSION

Children with genetically determined congenital anomalies need regular ophthalmic checkups to accurately assess the eye and determine the prospects of vision function development.

Mowat-Wilson syndrome: unraveling the complexities of diagnosis, treatment, and symptom management

Mowat-Wilson syndrome can be mentioned as one of the most severe and, at the same time, rare genetic abnormalities. The inheritance pattern of this disorder is an autosomal dominant pattern. In this disease, the ZEB2 gene becomes abnormal. The severity of the disease and associated signs and symptoms can vary widely but may include distinct facial features, developmental delay, intellectual disability, and Hirschsprung. MWS treatment may vary based on the specific symptoms that appear in each individual. This review will examine the gene involved in this disease, phenotype, clinical manifestations, ways of diagnosis, and treatment of this disease.

Clinical Characteristics and Novel ZEB2 Gene Mutation Analysis of Three Chinese Patients with Mowat-Wilson Syndrome

Purpose

Mowat-Wilson syndrome (MWS) is an autosomal dominant disease caused by a pathogenic variant of the ZEB2 gene. The main clinical manifestations include special facial features, Hirschsprung disease (HSCR), global developmental delay and other congenital malformations. Here, we summarize the clinical characteristics and genetic mutation analysis of three Chinese patients with MWS.

Patients and Methods

The clinical characteristics of the patients were monitored and the treatment effect was followed up. DNA was extracted from peripheral blood and analyzed by sequencing. Whole exome sequencing was then performed.

Results

Three novel ZEB2 gene mutations were identified in 3 patients (c.1147_1150dupGAAC, p.Q384Rfs*7, c.1137_1146del TAGTATGTCT, p.S380Nfs *13 and c.2718delT, p.A907Lfs*23). They all had special facial features, intellectual disability, developmental delay, microcephaly, structural brain abnormalities and other symptoms. After long-term regular rehabilitation treatment, the development quotient of each functional area of the patient was slightly improved.

Conclusion

Our study expanded the mutation spectrum of ZEB2 and enriched our understanding of the clinical features of MWS. It also shows that long-term standardized treatment is of great significance for the prognosis of patients.

The science of Hirschsprung disease: What we know and where we are headed

The enteric nervous system (ENS) is a rich network of neurons and glial cells that comprise the gastrointestinal tract's intrinsic nervous system and are responsible for controlling numerous complex functions, including digestion, transit, secretion, barrier function, and maintenance of a healthy microbiome. Development of a functional ENS relies on the coordinated interaction between enteric neural crest-derived cells and their environment as the neural crest-derived cells migrate rostrocaudally along the embryonic gut mesenchyme. Congenital or acquired disruption of ENS development leads to various neurointestinal diseases. Hirschsprung disease is a congenital neurocristopathy, a disease of the neural crest. It is characterized by a variable length of distal colonic aganglionosis due to a failure in enteric neural crest-derived cell proliferation, migration, differentiation, and/or survival. In this review, we will review the science of Hirschsprung disease, targeting an audience of pediatric surgeons. We will discuss the basic biology of normal ENS development, as well as what goes awry in ENS development in Hirschsprung disease. We will review animal models that have been integral to studying this disease, as well as current hot topics and future research, including genetic risk profiling, stem cell therapy, non-invasive diagnostic techniques, single-cell sequencing techniques, and genotype-phenotype correlation.

Hirschsprung disease outcomes

Hirschsprung disease (HD) is a complex surgical and medical problem that appears to have varied health and social outcomes with the age and neurodevelopmental state of patients. In general, long-term outcomes are thought to be good for the majority of patients despite recognized problems with constipation and/or fecal incontinence. However, there are no universally accepted pathways regarding post-operative bowel management programs nor clearly defined follow-up pathways making the current outcome measures difficult to interpret. Further, other factors that may influence outcome including age at the time of procedure and procedure type continue to lack consensus. Improved support of children in resource limited environments and during periods of transition into the adult medical care environment are needed to improve outcome.  Recent proliferation of multidisciplinary care teams and consortia may help to better understand outcomes and address current knowledge gaps. Continuing these collaborations will be imperative to continuing improvements in care which may ultimately impact outcome.

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.

scRNA-Seq Reveals New Enteric Nervous System Roles for GDNF, NRTN, and TBX3

BACKGROUND AND AIMS

Bowel function requires coordinated activity of diverse enteric neuron subtypes. Our aim was to define gene expression in these neuron subtypes to facilitate development of novel therapeutic approaches to treat devastating enteric neuropathies, and to learn more about enteric nervous system function.

METHODS

To identify subtype-specific genes, we performed single-nucleus RNA-seq on adult mouse and human colon myenteric plexus, and single-cell RNA-seq on E17.5 mouse ENS cells from whole bowel. We used immunohistochemistry, select mutant mice, and calcium imaging to validate and extend results.

RESULTS

RNA-seq on 635 adult mouse colon myenteric neurons and 707 E17.5 neurons from whole bowel defined seven adult neuron subtypes, eight E17.5 neuron subtypes and hundreds of differentially expressed genes. Manually dissected human colon myenteric plexus yielded RNA-seq data from 48 neurons, 3798 glia, 5568 smooth muscle, 377 interstitial cells of Cajal, and 2153 macrophages. Immunohistochemistry demonstrated differential expression for BNC2, PBX3, SATB1, RBFOX1, TBX2, and TBX3 in enteric neuron subtypes. Conditional Tbx3 loss reduced NOS1-expressing myenteric neurons. Differential Gfra1 and Gfra2 expression coupled with calcium imaging revealed that GDNF and neurturin acutely and differentially regulate activity of ∼50% of myenteric neurons with distinct effects on smooth muscle contractions.

CONCLUSION

Single cell analyses defined genes differentially expressed in myenteric neuron subtypes and new roles for TBX3, GDNF and NRTN. These data facilitate molecular diagnostic studies and novel therapeutics for bowel motility disorders.

Clinical and Molecular Spectrum of Four Patients Diagnosed with Mowat-Wilson Syndrome

Mowat-Wilson syndrome (MWS) is a rare autosomal dominant syndrome characterized by distinctive facial features, congenital heart defects, Hirschsprung disease, genitourinary anomalies, various structural brain anomalies, and intellectual disability. Pathogenic mutations that result in haploinsufficiency in the ZEB2 gene cause MWS. In this study, we aimed to evaluate the clinical features and molecular analysis results of 4 MWS patients. All patients were examined by an expert clinical geneticist. Dysmorphological abnormalities were recorded. Data including demographic, clinical, and laboratory findings were obtained from hospital records. ZEB2 gene analysis was performed using a Sanger sequencing method. All patients had typical facial features of MWS such as widely spaced eyes, broad eyebrows with a medial flare, low-hanging columella, prominent or pointed chin, open-mouth expression, and uplifted earlobes. Four different heterozygous mutations were identified; 2 mutations were frameshift (c.246_247delGGinsC, c.980_980delG), 1 was nonsense (c.2083C>T), and 1 was splice site (c.808-2A>G). Two of them (c.246_247delGGinsC, c.980_980delG) have not been previously reported in the literature. By defining 2 novel mutations, this study contributes to the molecular spectrum of MWS, while also providing a further insight for genetic counseling. It also demonstrates the importance of dysmorphological examination in clinical diagnosis.

Genotype-phenotype analysis in Mowat-Wilson syndrome associated with two novel and two recurrent variants

The current study aimed to analyze the genotype-phenotype relationship in patients with variants of zinc finger E box-binding homeobox 2 (ZEB2), which is a gene encoding a homeobox transcription factor known to be mutated in Mowat Wilson syndrome (MWS). Whole genome sequencing (WGS) was performed in 530 children, of whom 333 had epilepsy with or without developmental delay and 197 developmental delay alone. Pathogenic variants were identified and verified using Sanger sequencing, and the disease phenotypes of the corresponding patients were analyzed for features of MWS. WGS was performed in 333 children with epilepsy, with or without developmental delays or intellectual disability and 197 children with developmental delay alone. A total of 4 unrelated patients were indicated to be heterozygous for truncating mutations in ZEB2. A total of three of these were nonsense mutations (novel Gln1072X and recurrent Trp97X and Arg921X), and one was a frameshift mutation (novel Val357Aspfs*15). The mutations have occurred de novo as confirmed by Sanger sequence comparisons in patients and their parents. All 4 patients exhibited signs of MWS, whereby the severity increased the closer a mutation was located to the amino terminus of the protein. The results suggest that the clinical outcome in MWS depends on the relative position of the truncation in the ZEB2 gene. A number of interpretations of this genotype/phenotype association are discussed in the present study.

Mowat Wilson syndrome and Hirschsprung disease: a retrospective study on functional outcomes

AIM OF THE STUDY

Mowat Wilson syndrome (MWS) is a complex genetic disorder due to mutation or deletion of the ZEB2 gene (ZFHX1B), including multiple clinical features. Hirschsprung disease is associated with this syndrome with a prevalence between 43 and 57%. The aim of this study was to demonstrate the severe outcomes and the high complication rates in children with MWS, focusing on their complicated follow-up.

METHODS

A retrospective comparative study was conducted on patients referred to Robert-Debré Children's Hospital for MWS from 2003 to 2018. Multidisciplinary follow-up was carried out by surgeons, geneticists, gastroenterologists, and neurologists. Data regarding patient characteristics, surgical management, postoperative complications, and functional outcomes were collected.

RESULTS

Over this period of 15 years, 23 patients were diagnosed with MWS. Hirschsprung disease was associated with 10 of them (43%). Of these cases, two patients had recto-sigmoïd aganglionosis (20%), three had aganglionic segment extension to the left colic angle (30%), two to the right colic angle (20%), and three to the whole colon (30%). The median follow-up was 8.5 years (2 months-15 years). All patients had seizures and intellectual disability. Six children (60%) presented with cardiac defects. At the last follow-up, three patients still had a stoma diversion and 7 (70%) were fed orally. One patient died during the first months. Eight (80%) of these children required a second surgery due to complications. At the last follow-up, three patients reported episodes of abdominal bloating (42%), one recurrent treated constipation (14.3%), and one soiling (14.3%). Genetic analysis identified three patients with heterozygous deletions, three with codon mutations, and three with frameshift mutations.

CONCLUSIONS

MWS associated with Hirschsprung disease has a high rate of immediate surgical complications but some patients may achieve bowel function comparable with non-syndromic HD patients. A multidisciplinary follow-up is required for these patients.

LEVEL OF EVIDENCE

Retrospective observational single cohort study, Level 3.

Distinctive genetic variation of long-segment Hirschsprung's disease in Taiwan

BACKGROUND

Hirschsprung's disease (HSCR) is a congenital disorder with the absence of myenteric and submucosal ganglion cells within distal gut. Due to multigenic inheritance and interactions, we employed next-generation sequencing (NGS) to investigate genetic backgrounds of long-segment HSCR (L-HSCR) in Taiwan.

METHODS

Genomic DNA extracted from peripheral blood of L-HSCR patients was subjected to capture-based NGS, based on a 31-gene panel. The variants with allele frequency <0.05 and predicted by computational methods as deleterious were further validated by Sanger sequencing in patients and their family as well to tell de novo from inherited variants.

RESULTS

Between 2015/04 and 2018/05, this study enrolled 23 L-HSCR patients, including 15 (65.2%) sporadic cases and 8 (34.8%) familial patients in 4 different families. Six sporadic and seven familial cases showed possible harmful variants across eight different genes, accounting for an overall detection rate of 56.5%. These variants mainly resided in SEMA3C, followed by RET, NRG1, and NTRK1. Three sporadic and 2 familial cases exhibited strong pathogenic variants as a deletional frameshift or stop codon in RET, L1CAM or NRG1. In a HSCR family, the father passed on a pathogenic RET frameshift to two daughters; however, only one developed HSCR.

CONCLUSION

Using NGS, we disclosed deleterious mutations such as a frameshift or stop codon in either familial or sporadic patients. Our cases with isolated L-HSCR or even total colonic aganglionosis appeared to exhibit complex patterns of inheritance and incomplete penetrance even in families with the same genetic variants, reflecting the possible effects of environmental factors and genetic modifiers.

Fetal diagnosis of Mowat-Wilson syndrome by whole exome sequencing

Mowat-Wilson syndrome (MWS) is a complex genetic disorder associated with heterozygous variation in ZEB2. It is mainly characterized by moderate-to-severe intellectual disability, facial dysmorphism, epilepsy, and various malformations including Hirschsprung disease, corpus callosum anomalies, and congenital heart defects. It is rarely diagnosed prenatally and there is limited information available on the prenatal phenotype associated with MWS. Here we report the detection of a heterozygous de novo nonsense variant in ZEB2 by whole exome sequencing in a fetus with microphthalmia in addition to cardiac defects and typical MWS facial dysmorphism. As the prenatal phenotypic spectrum of MWS expands, the routine addition of fetal genomic testing particularly in the presence of multiple malformations will increase both the sensitivity and specificity of prenatal diagnostics.

Neurocristopathies: New insights 150 years after the neural crest discovery

The neural crest (NC) is a transient, multipotent and migratory cell population that generates an astonishingly diverse array of cell types during vertebrate development. These cells, which originate from the ectoderm in a region lateral to the neural plate in the neural fold, give rise to neurons, glia, melanocytes, chondrocytes, smooth muscle cells, odontoblasts and neuroendocrine cells, among others. Neurocristopathies (NCP) are a class of pathologies occurring in vertebrates, especially in humans that result from the abnormal specification, migration, differentiation or death of neural crest cells during embryonic development. Various pigment, skin, thyroid and hearing disorders, craniofacial and heart abnormalities, malfunctions of the digestive tract and tumors can also be considered as neurocristopathies. In this review we revisit the current classification and propose a new way to classify NCP based on the embryonic origin of the affected tissues, on recent findings regarding the molecular mechanisms that drive NC formation, and on the increased complexity of current molecular embryology techniques.

Phenotype and genotype of 87 patients with Mowat-Wilson syndrome and recommendations for care

PURPOSE

Mowat-Wilson syndrome (MWS) is a rare intellectual disability/multiple congenital anomalies syndrome caused by heterozygous mutation of the ZEB2 gene. It is generally underestimated because its rarity and phenotypic variability sometimes make it difficult to recognize. Here, we aimed to better delineate the phenotype, natural history, and genotype-phenotype correlations of MWS.

METHODS

In a collaborative study, we analyzed clinical data for 87 patients with molecularly confirmed diagnosis. We described the prevalence of all clinical aspects, including attainment of neurodevelopmental milestones, and compared the data with the various types of underlying ZEB2 pathogenic variations.

RESULTS

All anthropometric, somatic, and behavioral features reported here outline a variable but highly consistent phenotype. By presenting the most comprehensive evaluation of MWS to date, we define its clinical evolution occurring with age and derive suggestions for patient management. Furthermore, we observe that its severity correlates with the kind of ZEB2 variation involved, ranging from ZEB2 locus deletions, associated with severe phenotypes, to rare nonmissense intragenic mutations predicted to preserve some ZEB2 protein functionality, accompanying milder clinical presentations.

CONCLUSION

Knowledge of the phenotypic spectrum of MWS and its correlation with the genotype will improve its detection rate and the prediction of its features, thus improving patient care.

Hirschsprung disease-Bowel function beyond childhood

Hirschsprung disease is a developmental defect of the enteric nervous system characterized by lack of enteric neurons in the distal hindgut. There are numerous reports on short-term outcomes indicating that impaired bowel function is common. Recently, several controlled studies show that bowel function outcomes are affected beyond childhood, in adolescents and adults, compared with healthy control subjects. Constipation and fecal incontinence are common. The impaired bowel function appears to have a negative impact on quality of life, although, a majority of patients have adapted to their symptoms. On the other hand, Hirschsprung disease seems to have limited impact on education and occupation in adult life. The aim of this review was to summarize current knowledge of bowel function outcome beyond childhood in patients with Hirschsprung disease.

The use of stomas in the early management of Hirschsprung disease: Findings of a national, prospective cohort study

BACKGROUND/PURPOSE

Primary pull-through without a stoma has become preferred practice in managing Hirschsprung disease (HD). The aims of this study were to establish stoma rate and identify factors associated with stoma formation in a population-based cohort in the UK and Ireland.

METHODS

Live-born infants with HD were prospectively identified in all 28 specialist pediatric surgical units in the UK and Ireland between October 2010 to September 2012. Method of colonic decompression was recorded and multivariable logistic regression was used to identify factors associated with stoma formation.

RESULTS

305 infants with HD were identified. Rectal washouts were initially used in 86% (263) with a defunctioning stoma formed as the primary management in 13% (39). Ultimately, 36% (111) required a stoma prior to definitive surgery. Compared to infants managed with rectal washouts alone; infants managed with a stoma were more likely to have a transition zone proximal to the splenic flexure, Down (or another) syndrome, and HD diagnosis established more than 28days after presentation.

CONCLUSIONS

Although rectal washouts are commonly employed, a stoma prior to definitive surgery was required in 36% of infants in a national cohort. Delayed diagnosis, aganglionosis proximal to the splenic flexure and presence of other anomalies are associated with stoma formation.

TYPE OF STUDY AND LEVEL OF EVIDENCE

Prognosis study (high-quality prospective cohort study with 80% follow-up and all patients enrolled at same time point in disease).

A Novel Partial Duplication of ZEB2 and Review of ZEB2 Involvement in Mowat-Wilson Syndrome

Mowat-Wilson syndrome is a rare genetic condition characterized by intellectual disability, structural anomalies, and dysmorphic features. It is caused by haploinsufficiency of the ZEB2 gene in chromosome 2q22.3. Over 180 distinct mutations in ZEB2 have been reported, including nonsense and missense point mutations, deletions, and large chromosomal rearrangements. We report on a 14-year-old female with a clinical diagnosis of Mowat-Wilson syndrome. Chromosomal microarray identified a novel de novo 69-kb duplication containing exons 1 and 2 of the ZEB2 gene. Sequence analysis identified no other variants in this gene. This is the first report of a partial duplication of the ZEB2 gene resulting in Mowat-Wilson syndrome.

A systematic review of the quality of conduct and reporting of systematic reviews and meta-analyses in paediatric surgery

OBJECTIVE

Our objective was to evaluate quality of conduct and reporting of published systematic reviews and meta-analyses in paediatric surgery. We also aimed to identify characteristics predictive of review quality.

BACKGROUND

Systematic reviews summarise evidence by combining sources, but are potentially prone to bias. To counter this, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was published to aid in reporting. Similarly, the Assessing the Methodological Quality of Systematic Reviews (AMSTAR) measurement tool was designed to appraise methodology. The paediatric surgical literature has seen an increasing number of reviews over the past decade, but quality has not been evaluated.

METHODS

Adhering to PRISMA guidelines, we performed a systematic review with a priori design to identify systematic reviews and meta-analyses of interventions in paediatric surgery. From 01/2010 to 06/2016, we searched: MEDLINE, EMBASE, Cochrane, Centre for Reviews and Dissemination, Web of Science, Google Scholar, reference lists and journals. Two reviewers independently selected studies and extracted data. We assessed conduct and reporting using AMSTAR and PRISMA. Scores were calculated as the sum of reported items. We also extracted author, journal and article characteristics, and used them in exploratory analysis to determine which variables predict quality.

RESULTS

112 articles fulfilled eligibility criteria (53 systematic reviews; 59 meta-analyses). Overall, 68% AMSTAR and 56.8% PRISMA items were reported adequately. Poorest scores were identified with regards a priori design, inclusion of structured summaries, including the grey literature, citing excluded articles and evaluating bias. 13 reviews were pre-registered and 6 in PRISMA-endorsing journals. The following predicted quality in univariate analysis:, word count, Cochrane review, journal h-index, impact factor, journal endorses PRISMA, PRISMA adherence suggested in author guidance, article mentions PRISMA, review includes comparison of interventions and review registration. The latter three variables were significant in multivariate regression.

CONCLUSIONS

There are gaps in the conduct and reporting of systematic reviews in paediatric surgery. More endorsement by journals of the PRISMA guideline may improve review quality, and the dissemination of reliable evidence to paediatric clinicians.

Incontinence and psychological symptoms in individuals with Mowat-Wilson Syndrome

BACKGROUND

Mowat-Wilson Syndrome (MWS) is caused by deletion/mutation of the ZEB2 gene on chromosome 2q22. MWS is characterized by a distinctive facial appearance, severe intellectual disability and other anomalies, e.g. seizures and/or Hirschsprung disease (HSCR). Most individuals have a sociable demeanor, but one third show psychological problems.

AIMS

The aim was to investigate incontinence and psychological problems in MWS.

METHODS AND PROCEDURES

26 children (4-12 years), 13 teens (13-17 years) and 8 adults (>18years) were recruited through a MWS support group. The Parental Questionnaire: Enuresis/Urinary Incontinence, as well as the Developmental Behaviour Checklist (DBC) were completed by parents or care-givers.

OUTCOMES AND RESULTS

97.7% of persons with MWS had incontinence (nocturnal enuresis 74.4%; daytime urinary incontinence 76.2%; fecal incontinence 81.4%). Incontinence remained high over age groups (children 95.8%, teens 100%, adults 100%). 46.2% of children, 25% of teens and 37.5% of adults exceeded the clinical cut-off on the DBC. The ability to use the toilet for micturition improved with age.

CONCLUSIONS AND IMPLICATIONS

MWS incontinence rates are very high. All had physical disabilities including anomalies of the genitourinary and gastrointestinal tract. Due to the high prevalence rates, a screening for incontinence and psychological problems in MWS is recommended.

Experience of Mowat-Wilson syndrome prenatal diagnosis for a Chinese family

Mowat–Wilson syndrome (MWS) is a complex developmental disorder. We report the first prenatal diagnosis provided for a family in mainland China after identifying the causal mutation for the proband. Special focus on MWS‐related organs during prenatal ultrasound scan is described which is extremely important for genetic counseling of parents.