Prenatal diagnosis of fetal growth restriction with polyhydramnios, etiology and impact on postnatal outcome

To assess the spectrum of different etiologies, the intrauterine course, outcome and possible prognostic markers in prenatally detected fetal growth restriction (FGR) combined with polyhydramnios. Retrospective study of 153 cases with FGR combined with Polyhydramnios diagnosed by prenatal ultrasound over a period of 17 years. Charts were reviewed for ultrasound findings, prenatal and postnatal outcome. All cases were categorized into etiological groups and examined for differences. Five etiological groups were identified: chromosomal anomalies (n = 64, 41.8%), complex malformation syndromes (n = 37, 24.1%), isolated malformations (n = 24, 15.7%), musculoskeletal disorders (n = 14, 9.2%) and prenatal non-anomalous fetuses (n = 14, 9.2%). Subgroups showed significant disparities in initial diagnosis of combination of both pathologies, Ratio AFI/ gestational weeks and Doppler ultrasound examinations. Overall mortality rate was 64.7%. Fetuses prenatally assigned to be non-anomalous, showed further complications in 42.9% (n = 6). Fetuses prenatally diagnosed with FGR combined with polyhydramnios are affected by a high morbidity and mortality. Five etiologic groups can be differentiated, showing significant disparities in prenatal and postnatal outcome. Even without recognizable patterns prenatally, long-term-follow up is necessary, as neurodevelopmental or growth delay may occur.

Molecular Bases of Human Malformation Syndromes Involving the SHH Pathway: GLIA/R Balance and Cardinal Phenotypes

Human hereditary malformation syndromes are caused by mutations in the genes of the signal transduction molecules involved in fetal development. Among them, the Sonic hedgehog (SHH) signaling pathway is the most important, and many syndromes result from its disruption. In this review, we summarize the molecular mechanisms and role in embryonic morphogenesis of the SHH pathway, then classify the phenotype of each malformation syndrome associated with mutations of major molecules in the pathway. The output of the SHH pathway is shown as GLI activity, which is generated by SHH in a concentration-dependent manner, i.e., the sum of activating form of GLI (GLIA) and repressive form of GLI (GLIR). Which gene is mutated and whether the mutation is loss-of-function or gain-of-function determine in which concentration range of SHH the imbalance occurs. In human malformation syndromes, too much or too little GLI activity produces symmetric phenotypes affecting brain size, craniofacial (midface) dysmorphism, and orientation of polydactyly with respect to the axis of the limb. The symptoms of each syndrome can be explained by the GLIA/R balance model.

Case Report of Idiopathic Masseteric Hypoplasia Treated With PMMA-Collagen Gel

Congenital hypoplasia of the masseter muscle is a rare condition most commonly associated with craniofacial or poly-malformation syndromes, with a small number of reported idiopathic cases. The condition is most commonly managed by orthodonture and later surgical intervention; however, surgery is not an option for all patients. Non-surgical approaches to correcting asymmetry may be considered for patients for whom the functional impact of hypoplasia has been largely managed and the patient’s concern is primarily aesthetic. In this case study, the patient presented for a consultation seeking a non-surgical solution for marked facial asymmetry. The patient underwent physical examination and magnetic resonance imaging to confirm diagnosis of congenital masseter muscle hypoplasia. To treat the asymmetry, a total of 9.6 cc of PMMA-collagen gel (Bellafill ®; Suneva Medical, Inc., San Diego, CA) was injected along the border of the mandible from the gonial angle out to the area of the mental foramen and slightly above over the course of 6 months (2 visits spaced 3 months apart) to provide long-term, non-surgical correction. The patient was very satisfied with the results, highlighting the potential for PMMA-collagen gel to be used in clinical situations in which durable, non-surgical correction of lower-face asymmetry is needed.

Familial cleft tongue caused by a unique translation initiation codon variant in TP63

Variants in transcription factor p63 have been linked to several autosomal dominantly inherited malformation syndromes. These disorders show overlapping phenotypic characteristics with various combinations of the following features: ectodermal dysplasia, split-hand/foot malformation/syndactyly, lacrimal duct obstruction, hypoplastic breasts and/or nipples, ankyloblepharon filiforme adnatum, hypospadias and cleft lip/palate. We describe a family with six individuals presenting with a striking novel phenotype characterized by a furrowed or cleft tongue, a narrow face, reddish hair, freckles and various foot deformities. Whole-exome sequencing (WES) identified a novel heterozygous variant, c.3G>T, in TP63 affecting the translation initiation codon (p.1Met?). Sanger sequencing confirmed dominant inheritance of this unique variant in all six affected family members. In summary, our findings indicate that heterozygous variants in TP63 affecting the first translation initiation codon result in a novel phenotype dominated by a cleft tongue, expanding the complex genotypic and phenotypic spectrum of TP63-associated disorders.

Unravelling the genetic causes of multiple malformation syndromes: A whole exome sequencing study of the Cypriot population

Multiple malformation syndromes (MMS) belong to a group of genetic disorders characterised by neurodevelopmental anomalies and congenital malformations. Here we explore for the first time the genetic aetiology of MMS using whole-exome sequencing (WES) in undiagnosed patients from the Greek-Cypriot population after prior extensive diagnostics workup including karyotype and array-CGH. A total of 100 individuals (37 affected), from 32 families were recruited and family-based WES was applied to detect causative single-nucleotide variants (SNVs) and indels. A genetic diagnosis was reported for 16 MMS patients (43.2%), with 10/17 (58.8%) of the findings being novel. All autosomal dominant findings occurred de novo. Functional studies were also performed to elucidate the molecular mechanism relevant to the abnormal phenotypes, in cases where the clinical significance of the findings was unclear. The 17 variants identified in our cohort were located in 14 genes (PCNT, UBE3A, KAT6A, SPR, POMGNT1, PIEZO2, PXDN, KDM6A, PHIP, HECW2, TFAP2A, CNOT3, AGTPBP1 and GAMT). This study has highlighted the efficacy of WES through the high detection rate (43.2%) achieved for a challenging category of undiagnosed patients with MMS compared to other conventional diagnostic testing methods (10–20% for array-CGH and ~3% for G-banding karyotype analysis). As a result, family-based WES could potentially be considered as a first-tier cost effective diagnostic test for patients with MMS that facilitates better patient management, prognosis and offer accurate recurrence risks to the families.

The etiology of cardiac hypertrophy in infants

This study aimed to describe the variety of etiologies currently identified in infants with cardiac hypertrophy (CH) and investigate whether there is a relation with hyperinsulinism, echocardiographic characteristics and prognosis. This retrospective cohort study included infants born between 2005 and 2018 with CH measured by echocardiography [interventricular septum (IVS) and/or left ventricular posterior wall (LVPW) thickness with Z-score ≥ 2.0]. Children with congenital heart disease or hypertension were excluded. Underlying diagnosis, echocardiographic and follow-up data were extracted from patient files. Seventy-one infants with CH were included. An underlying cause of CH was identified in two-thirds (n = 47). Most common etiologies of CH were malformation syndromes (n = 23, including Noonan n = 12) and maternal diabetes mellitus (n = 13). Less common causes were congenital hyperinsulinism (n = 3), metabolic- (n = 5), sarcomeric- (n = 2) and neuromuscular disease (n = 1). In half of the identified causes (n = 22) an association with hyperinsulinism was described, including maternal diabetes mellitus (n = 13), malformation syndromes with insulin resistance (n = 6) and congenital hyperinsulinism (n = 3). CH associated with hyperinsulinism was echocardiographically characterized by lower LVPW thickness, higher IVS:LVPW ratio and more frequent sole involvement of the IVS (all, p ≤ 0.02). CH associated with hyperinsulinism normalized more often (41 vs. 0%) with lower mortality rates (14 vs. 44%) compared to CH not associated with hyperinsulinism (all, p ≤ 0.03). Nowadays, an etiology of CH can be identified in the majority of infants. The development of CH is often associated with hyperinsulinism which is mainly characterized by focal hypertrophy of the IVS on echocardiography. Prognosis depends on the underlying cause and is more favorable in CH associated with hyperinsulinism.

Prenatal Diagnosis of Fetal Growth Restriction With Polyhydramnios: Etiology and Impact on Postnatal Outcome

Purpose: To assess the spectrum of different etiologies, the intrauterine course, outcome and possible prognostic markers in prenatally detected fetal growth restriction (FGR) combined with polyhydramnios. Methods: Retrospective study of 153 cases with FGR combined with Polyhydramnios diagnosed by prenatal ultrasound over a period of 17 years. Charts were reviewed for ultrasound findings, prenatal and postnatal outcome. All cases were categorized into etiological groups and examined for differences.Results: Five etiological groups were identified: chromosomal anomalies (n= 64, 41.8 %), complex malformation syndromes (n=37, 24.1 %), isolated malformations (n=24, 15.7 %), musculoskeletal disorders (n=14, 9.2 %) and prenatal non-anomalous fetuses (n=14, 9.2 %). Subgroups showed significant disparities in initial diagnosis of combination of both pathologies, Ratio AFI/ gestational weeks and Doppler ultrasound examinations. Overall mortality rate was 64.7 %. Fetuses prenatally assigned to be non-anomalous, showed further complications in 42.9 % (n=6). Conclusion: Fetuses prenatally diagnosed with FGR combined with polyhydramnios are affected by a high morbidity and mortality. Five etiologic groups can be differentiated, showing significant disparities in prenatal and postnatal outcome. Even without recognizable patterns prenatally, long-term-follow up is necessary, as neurodevelopmental or growth delay may occur.

Somatic Mosaicism in the Pathogenesis of de novo Cerebral Arteriovenous Malformations: A Paradigm Shift Implicating the RAS-MAPK Signaling Cascade

Cerebral arteriovenous malformations (AVMs) are leading causes of lesional hemorrhagic stroke in both the pediatric and young adult population, with sporadic AVMs accounting for the majority of cases. Recent evidence has identified somatic mosaicism in key proximal components of the RAS-MAPK signaling cascade within endothelial cells collected from human sporadic cerebral AVMs, with early preclinical models supporting a potential causal role for these mutations in the pathogenesis of these malformations. Germline mutations that predispose to deregulation of the RAS-MAPK signaling axis have also been identified in hereditary vascular malformation syndromes, highlighting the key role of this signaling axis in global AVM development. Herein, we review the most recent genomic and preclinical evidence implicating somatic mosaicism in the RAS-MAPK signaling pathway in the pathogenesis of sporadic cerebral AVMs. Also, we review evidence for RAS-MAPK dysregulation in hereditary vascular malformation syndromes and present a hypothesis suggesting that this pathway is central for the development of both sporadic and syndrome-associated AVMs. Finally, we examine the clinical implications of these recent discoveries and highlight potential therapeutic targets within this signaling pathway.

Rare Pathogenic Copy Number Variation in the 16p11.2 (BP4–BP5) Region Associated with Neurodevelopmental and Neuropsychiatric Disorders: A Review of the Literature

Copy number variants (CNVs) play an important role in the genetic underpinnings of neuropsychiatric/neurodevelopmental disorders. The chromosomal region 16p11.2 (BP4–BP5) harbours both deletions and duplications that are associated in carriers with neurodevelopmental and neuropsychiatric conditions as well as several rare disorders including congenital malformation syndromes. The aim of this article is to provide a review of the current knowledge of the diverse neurodevelopmental disorders (NDD) associated with 16p11.2 deletions and duplications reported in published cohorts. A literature review was conducted using the PubMed/MEDLINE electronic database limited to papers published in English between 1 January 2010 and 31 July 2020, describing 16p11.2 deletions and duplications carriers’ cohorts. Twelve articles meeting inclusion criteria were reviewed from the 75 articles identified by the search. Of these twelve papers, eight described both deletions and duplications, three described deletions only and one described duplications only. This study highlights the heterogeneity of NDD descriptions of the selected cohorts and inconsistencies concerning accuracy of data reporting.

Bifid epiglottis with midline laryngeal hamartoma: a rare presentation of Pallister Hall syndrome

Bifid epiglottis is a rare laryngeal anomaly that can be an isolated occurrence or as part of malformation syndromes, commonly the Pallister Hall syndrome (PHS). PHS presents with hypothalamic hamartomas, polysyndactyly, bifid epiglottis, imperforate anus and genitourinary abnormalities. We report a case of a 22 months old male child with features of PHS and Hirschsprung's disease. The presentations are with a hypothalamic mass, a bifid epiglottis and a midline mass in the larynx with symptoms of respiratory distress. The laryngeal lesion was endoscopically excised and its histology confirmed as hamartoma (laryngeal). The importance of an early diagnosis of PHS, genetic counselling and prompt management of a compromised airway and endocrine abnormalities is emphasized to have a better outcome.