Multiple Congenital Anomaly Syndrome Research Articles

Activation of WNT signaling restores the facial deficits in a zebrafish with defects in cholesterol metabolism.

SummaryInborn errors of cholesterol metabolism occur as a result of mutations in the cholesterol synthesis pathway (CSP). Although mutations in the CSP cause a multiple congenital anomaly syndrome, craniofacial abnormalities are a hallmark phenotype associated with these disorders. Previous studies have established that mutation of the zebrafish hmgcs1 gene (Vu57 allele), which encodes the first enzyme in the CSP, causes defects in craniofacial development and abnormal neural crest cell (NCC) differentiation. However, the molecular mechanisms by which the products of the CSP disrupt NCC differentiation are not completely known. Cholesterol is known to regulate the activity of WNT signaling, an established regulator of NCC differentiation. We hypothesized that defects in cholesterol synthesis are associated with reduced WNT signaling, consequently resulting in abnormal craniofacial development. To test our hypothesis we performed a combination of pharmaceutical inhibition, gene expression assays, and targeted rescue experiments to understand the function of the CSP and WNT signaling during craniofacial development. We demonstrate reduced expression of four canonical WNT downstream target genes in homozygous carriers of the Vu57 allele and reduced axin2 expression, a known WNT target gene, in larvae treated with Ro‐48‐8071, an inhibitor of cholesterol synthesis. Moreover, activation of WNT signaling via treatment with WNT agonist I completely restored the craniofacial defects present in a subset of animals carrying the Vu57 allele. Collectively, these data suggest interplay between the CSP and WNT signaling during craniofacial development.

The variability of SMARCA4-related Coffin-Siris syndrome: Do nonsense candidate variants add to milder phenotypes?

SMARCA4 encodes a central ATPase subunit in the BRG1-/BRM-associated factors (BAF) or polybromo-associated BAF (PBAF) complex in humans, which is responsible in part for chromatin remodeling and transcriptional regulation. Variants in this and other genes encoding BAF/PBAF complexes have been implicated in Coffin-Siris Syndrome, a multiple congenital anomaly syndrome classically characterized by learning and developmental differences, coarse facial features, hypertrichosis, and underdevelopment of the fifth digits/nails of the hands and feet. Individuals with SMARCA4 variants have been previously reported and appear to display a variable phenotype. We describe here a cohort of 15 unrelated individuals with SMARCA4 variants from the Coffin-Siris syndrome/BAF pathway disorders registry who further display variability in severity and degrees of learning impairment and health issues. Within this cohort, we also report two individuals with novel nonsense variants who appear to have a phenotype of milder learning/behavioral differences and no organ-system involvement.

Psychomotor, cognitive, and socio-emotional developmental profiles of children with Rubinstein-Taybi Syndrome and a severe intellectual disability

ABSTRACT Background: Rubinstein-Taybi syndrome (RSTS) is a multiple congenital anomaly syndrome characterised by several typical somatic characteristics and by developmental disabilities with various degrees of severity. Focusing on children with RSTS, the aim of this study was to describe their psychomotor, cognitive, and socio-emotional developmental profiles. Method: Twenty-three children with RSTS (12 boys; 11 girls; mean chronological age: 4 years and 10 months) with severe intellectual disability (mean developmental quotient = 32.39) were recruited from an Expert Department of Medical Genetics. Developmental assessments were carried out with the Brunet-Lézine-Revised scale and the Social Cognitive Evaluation Battery. Results: The participants’ developmental profiles were characterised by heterogeneous psychomotor development, homogeneous cognitive and socio-emotional development, by more severe delays in expressive language, vocal imitation, and symbolic play skills, and by better developmental levels in socio-emotional abilities. Conclusions: Based on these atypical developmental profiles, early interventions should target the three most delayed abilities.

Unilateral, frontal polymicrogyria and supratentorial white matter microcysts in fetus with Joubert syndrome and related disorders: Prenatal diagnosis with magnetic resonance imaging

Introduction. Joubert syndrome (JS) and related disorders (JSRD) are a group of rare multiple congenital anomalies syndromes, defined by complex midbrain-hindbrain malformation that creates the ?molar tooth sign? (MTS) on brain imaging and may be associated with multisystem organ pathology, mainly of the retina, kidney, liver and skeleton. Prenatal diagnosis of JSRD has proved difficult because of the rarity of the condition and low sensitivity of ultrasound in evaluation of the fetal posterior fossa (PF) in most affected fetuses. Case report. We presented an unusual case of JSRD, pure Joubert syndrome with unilateral frontal polymicrogyria and supratentorial white matter microcysts, diagnosed by magnetic resonance imaging (MRI), in fetus aged 30 gestational weeks. The distinctive MRI features of this rare ciliopathy were confirmed by 6-months postnatal MRI study. The postnatal outcome was poor; clinical follow- up in the first 6 months of life confirmed hypotonia, developmental delay, oculomotor apraxia and seizures. Conclusion. To the best of our knowledge, fetal MRI features of the coexistence of pure JS and supratentorial abnormalities leading to postnatal cerebellar dysfunction and epilepsy, have never been reported before. Presented case may contribute to the broadening of the spectrum of sparse prenatal features of JRSD, and support the stand that presence of neuronal migration abnormalities can affect the clinical outcome and prognosis of fetuses with JSRD.

A rare Indian case of GAPO syndrome with dental and other findings

GAPO syndrome is an entity with multiple congenital anomalies syndrome involving connective tissue characterized by growth retardation, alopecia, pseudoanodontia, and optic atrophy (GAPO) syndrome. To date, only approximately 45 cases of this extremely rare syndrome have been reported. We present thee case of a 9-year Indian male patient with GAPO syndrome in association with craniosynostosis along with degenerating optic nerve, short stature, partial anodontia, abnormally thick maxillary buccal and lingual frenum, born first to parents showing consanguineous marriage; however, the intelligence quotient of the child was good.

Turner syndrome in diverse populations.

Turner syndrome (TS) is a common multiple congenital anomaly syndrome resulting from complete or partial absence of the second X chromosome. In this study, we explore the phenotype of TS in diverse populations using clinical examination and facial analysis technology. Clinical data from 78 individuals and images from 108 individuals with TS from 19 different countries were analyzed. Individuals were grouped into categories of African descent (African), Asian, Latin American, Caucasian (European descent), and Middle Eastern. The most common phenotype features across all population groups were short stature (86%), cubitus valgus (76%), and low posterior hairline 70%. Two facial analysis technology experiments were conducted: TS versus general population and TS versus Noonan syndrome. Across all ethnicities, facial analysis was accurate in diagnosing TS from frontal facial images as measured by the area under the curve (AUC). An AUC of 0.903 (p < .001) was found for TS versus general population controls and 0.925 (p < .001) for TS versus individuals with Noonan syndrome. In summary, we present consistent clinical findings from global populations with TS and additionally demonstrate that facial analysis technology can accurately distinguish TS from the general population and Noonan syndrome.

Phenotype delineation of ZNF462 related syndrome.

Zinc finger protein 462 (ZNF462) is a relatively newly discovered vertebrate specific protein with known critical roles in embryonic development in animal models. Two case reports and a case series study have described the phenotype of 10 individuals with ZNF462 loss of function variants. Herein, we present 14 new individuals with loss of function variants to the previous studies to delineate the syndrome of loss of function in ZNF462. Collectively, these 24 individuals present with recurring phenotypes that define a multiple congenital anomaly syndrome. Most have some form of developmental delay (79%) and a minority has autism spectrum disorder (33%). Characteristic facial features include ptosis (83%), down slanting palpebral fissures (58%), exaggerated Cupid's bow/wide philtrum (54%), and arched eyebrows (50%). Metopic ridging or craniosynostosis was found in a third of study participants and feeding problems in half. Other phenotype characteristics include dysgenesis of the corpus callosum in 25% of individuals, hypotonia in half, and structural heart defects in 21%. Using facial analysis technology, a computer algorithm applying deep learning was able to accurately differentiate individuals with ZNF462 loss of function variants from individuals with Noonan syndrome and healthy controls. In summary, we describe a multiple congenital anomaly syndrome associated with haploinsufficiency of ZNF462 that has distinct clinical characteristics and facial features.

Biallelic variants in CTU2 cause DREAM-PL syndrome and impair thiolation of tRNA wobble U34.

The wobble position in the anticodon loop of transfer ribonucleic acid (tRNA) is subject to numerous posttranscriptional modifications. In particular, thiolation of the wobble uridine has been shown to play an important role in codon-anticodon interactions. This modification is catalyzed by a highly conserved CTU1/CTU2 complex, disruption of which has been shown to cause abnormal phenotypes in yeast, worms, and plants. We have previously suggested that a single founder splicing variant in human CTU2 causes a novel multiple congenital anomalies syndrome consisting of dysmorphic facies, renal agenesis, ambiguous genitalia, microcephaly, polydactyly, and lissencephaly (DREAM-PL). In this study, we describe five new patients with DREAM-PL phenotype and whose molecular analysis expands the allelic heterogeneity of the syndrome to five different alleles; four of which predict protein truncation. Functional characterization using patient-derived cells for each of these alleles, as well as the original founder allele; revealed a specific impairment of wobble uridine thiolation in all known thiol-containing tRNAs. Our data establish a recognizable CTU2-linked autosomal recessive syndrome in humans characterized by defective thiolation of the wobble uridine. The potential deleterious consequences for the translational efficiency and fidelity during development as a mechanism for pathogenicity represent an attractive target of future investigations.

Autistic symptoms in Greig cephalopolysyndactyly syndrome: a family case report

BackgroundGreig cephalopolysyndactyly syndrome is a rare multiple congenital anomaly syndrome characterized by the triad of polysyndactyly (preaxial or mixed preaxial and postaxial), macrocephaly, and ocular hypertelorism. Little is known about the neuropsychological phenotype and the developmental features of this syndrome.Case presentationWe describe the clinical features of a 7-year-old Italian white boy affected by Greig cephalopolysyndactyly syndrome in comorbidity with autism spectrum disorder and the case of his 45-year-old white father, carrying the same point deletion (c.3677del) in the GLI3 gene and showing subclinical autistic symptoms. We performed a neuropsychiatric assessment of cognitive, adaptive, socio-communicative, and behavioral skills of the child. Concurrently, the father underwent his first psychiatric evaluation of cognitive skills and autistic symptoms.ConclusionsWe report the first clinical description of an association between autistic symptoms and Greig cephalopolysyndactyly syndrome in two members of the same family with the same genetic point deletion. Further research is required in order to draw an accurate conclusion regarding the association between Greig cephalopolysyndactyly syndrome and autism.

First International Conference on RASopathies and Neurofibromatoses in Asia: Identification and advances of new therapeutics.

The neurofibromatoses, which include neurofibromatosis type I (NF1), neurofibromatosis type II (NF2), and schwannomatosis, are a group of syndromes characterized by tumor growth in the nervous system. The RASopathies are a group of syndromes caused by germline mutations in genes that encode components of the RAS/mitogen-activated protein kinase (MAPK) pathway. The RASopathies include NF1, Noonan syndrome, Noonan syndrome with multiple lentigines, Costello syndrome, cardio-facio-cutaneous syndrome, Legius syndrome, capillary malformation arterio-venous malformation syndrome, and SYNGAP1 autism. Due to their common underlying pathogenetic etiology, all these syndromes have significant phenotypic overlap of which one common feature include a predisposition to tumors, which may be benign or malignant. Together as a group, they represent one of the most common multiple congenital anomaly syndromes estimating to affect approximately one in 1000 individuals worldwide. The subcontinent of India represents one of the largest populations in the world, yet remains underserved from an aspect of clinical genetics services. In an effort to bridge this gap, the First International Conference on RASopathies and Neurofibromatoses in Asia: Identification and Advances of New Therapeutics was held in Kochi, Kerala, India. These proceedings chronicle this timely and topical international symposium directed at discussing the best practices and therapies for individuals with neurofibromatoses and RASopathies.

Successful atrial septal defect transcatheter closure in a patient with pentalogy of Cantrell and ectopia cordis.

Pentalogy of Cantrell (PC) is an extremely rare multiple congenital anomaly syndrome, characterized by the presence of five major malformations: midline supraumbilical abdominal wall defect (which results in omphalocele), lower sternal defect, diaphragmatic pericardial defect, anterior diaphragmatic defect and various intracardiac malformations (mostly ventricular septal defect) [1]. Additionally, although not part of the classic PC, some severe cases have been associated with herniation of the heart through the diaphragmatic defect, resulting in ectopia cordis (EC) [2]. Such a diagnosis carries a disastrous prognosis without surgical correction or palliation [3]. Furthermore, miscellaneous intracardiac abnormalities even worsen the survival. Multiple chest interventions and complex anatomy impede their surgical treatment; therefore, the transcatheter approach may be the only possibility. According to our best knowledge, no percutaneous atrial septal defect (ASD) closure has been reported in a patient with PC.

Familial case of Fryns syndrome in two fetuses in second trimester

Fryns syndrome (FS) is a multiple congenital anomaly syndrome, inherited as an autosomal recessive defect with diagnostic triad including diaphragmatic hernia, abnormal face, and distal limb anomalies. Two cases of FS in the fetuses, whose mother had previous affected pregnancy with the infant having diaphragmatic hernia are presented. Both fetuses have atypical limb deformity, ectrodactyly. These cases illustrate the spectrum of FS and the importance of a family history in fetuses with congenital diaphragmatic hernia.

Benign and malignant tumors in Rubinstein-Taybi syndrome.

Rubinstein–Taybi syndrome (RSTS) is a multiple congenital anomalies syndrome associated with mutations in CREBBP (70%) and EP300 (5–10%). Previous reports have suggested an increased incidence of specific benign and possibly also malignant tumors. We identified all known individuals diagnosed with RSTS in the Netherlands until 2015 (n = 87) and studied the incidence and character of neoplastic tumors in relation to their CREBBP/EP300 alterations. The population–based Dutch RSTS data are compared to similar data of the Dutch general population and to an overview of case reports and series of all RSTS individuals with tumors reported in the literature to date. Using the Nationwide Network and Registry of Histopathology and Cytopathology in the Netherlands (PALGA Foundation), 35 benign and malignant tumors were observed in 26/87 individuals. Meningiomas and pilomatricomas were the most frequent benign tumors and their incidence was significantly elevated in comparison to the general Dutch population. Five malignant tumors were observed in four persons with RSTS (medulloblastoma; diffuse large‐cell B‐cell lymphoma; breast cancer; non‐small cell lung carcinoma; colon carcinoma). No clear genotype–phenotype correlation became evident. The Dutch population‐based data and reported case studies underscore the increased incidence of meningiomas and pilomatricomas in individuals with RSTS. There is no supporting evidence for an increased risk for malignant tumors in individuals with RSTS, however, due to the small numbers this risk may not be fully dismissed.

Fryns syndrome: A rare case report with review of literature

Fryns syndrome is a rare multiple congenital anomaly syndrome with incidence of 0.7-1 in 10,000 births. Characteristic features of this syndrome are congenital diaphragmatic hernia, lung hypoplasia, unusual facial features, limb defects and parental consanguinity. Here we report a case of Fryns syndrome of consanguineous parents at the gestation age of 27 week old. Mother presented to department of obstetrics and gynaecology with inability to perceive fetal movements. Ultasonography revealed polyhydramnios, intrauterine growth retardation, and congenital anomaly of diaphragm and absence of fetal heart sound. Based on ultrasound findings, clinical diagnosis of congenital diaphragmatic hernia was made for which therapeutic abortion was performed and a still born fetus was delivered which was sent for post mortem study. On autopsy, diagnosis of Fryns syndrome was made.

Desmosterolosis presenting with multiple congenital anomalies

Desmosterolosis is a rare multiple congenital anomaly syndrome caused by a defect in the enzyme 3-beta-hydroxysterol delta-24-reductase (DHCR24) in the cholesterol biosynthesis pathway. Defects in this enzyme cause increased level of the cholesterol precursor desmosterol while disrupting development of cholesterol, impacting embryogenesis. A total of 9 cases of desmosterolosis have been reported to date. We report a 20-month-old male from consanguineous parents with multiple congenital anomalies including corpus callosum hypoplasia, facial dysmorphism, cleft palate, pectus deformity, short and wide neck and distal contractures. On analysis of the regions of homozygosity found by microarray, we identified DHCR24 as a candidate gene. Sterol quantitation showed a desmosterol level of 162 μg/mL (nl: 0.82 ± 0.48). Genetic testing confirmed the diagnosis with a homozygous likely pathogenic mutation (p.Glu191Lys) in the DHCR24 gene. Our case expands the known diagnostic spectrum for Desmosterolosis. We suggest considering Desmosterolosis in the differential diagnosis of patients who present with concurrent agenesis of the corpus callosum with white matter atrophy and ventriculomegaly, retromicrognathia with or without cleft palate, hand contractures, and delay of growth and development. Children of consanguineous mattings may be at higher risk for rare recessive disorders and testing for cholesterol synthesis defect should be a consideration for affected children. Initial evaluation can be performed using sterol quantitation, followed by genetic testing.

Facies: the value of an old diagnostic tip in pediatric dermatology.

The authors examine what is meant as facies in medicine. After an introduction to the word's understanding, they move on listing some dermatological conditions associated to peculiar facies in the child. Starting from atopic dermatitis, the authors develop an algorithm including Genodermatoses, Neurocutaneous Disorders, and Multiple Congenital Anomalies Syndromes. They emphasize the distinctive features of the lesions on the face and their fundamental diagnostic importance.

Copy number variation as a genetic basis for heterotaxy and heterotaxy-spectrum congenital heart defects.

Genomic disorders and rare copy number abnormalities are identified in 15-25% of patients with syndromic conditions, but their prevalence in individuals with isolated birth defects is less clear. A spectrum of congenital heart defects (CHDs) is seen in heterotaxy, a highly heritable and genetically heterogeneous multiple congenital anomaly syndrome resulting from failure to properly establish left-right (L-R) organ asymmetry during early embryonic development. To identify novel genetic causes of heterotaxy, we analysed copy number variants (CNVs) in 225 patients with heterotaxy and heterotaxy-spectrum CHDs using array-based genotyping methods. Clinically relevant CNVs were identified in approximately 20% of patients and encompassed both known and putative heterotaxy genes. Patients were carefully phenotyped, revealing a significant association of abdominal situs inversus with pathogenic or likely pathogenic CNVs, while d-transposition of the great arteries was more frequently associated with common CNVs. Identified cytogenetic abnormalities ranged from large unbalanced translocations to smaller, kilobase-scale CNVs, including a rare, single exon deletion in ZIC3, a gene known to cause X-linked heterotaxy. Morpholino loss-of-function experiments in Xenopus support a role for one of these novel candidates, the platelet isoform of phosphofructokinase-1 (PFKP) in heterotaxy. Collectively, our results confirm a high CNV yield for array-based testing in patients with heterotaxy, and support use of CNV analysis for identification of novel biological processes relevant to human laterality.This article is part of the themed issue 'Provocative questions in left-right asymmetry'.

A Chinese patient with Toriello–Carey syndrome and an interstitial deletion of 3q

Toriello-Carey syndrome (T-CS), which was first described by Toriello and Carey, is a rare multiple congenital anomaly syndrome characterized by agenesis of the corpus callosum, Pierre Robin sequence, unusual facial appearance, and other anomalies. Tracheal or laryngeal anomalies are reported as a common manifestation of T-CS. These anomalies can lead to respiratory distress and respiratory tract infection. The cause of T-CS is unknown, although there have been reports of patients with a clinical diagnosis of T-CS and a chromosome anomaly. We describe another such patient who was found to have an interstitial deletion of 3q (3q12.1-q21.3). © 2016 Wiley Periodicals, Inc.

Complex phenotypes blur conventional borders between Say–Barber–Biesecker–Young–Simpson syndrome and genitopatellar syndrome

Say-Barber-Biesecker-Young-Simpson syndrome (SBBYSS) and genitopatellar syndrome (GTPTS) are clinically similar disorders with some overlapping features. Although they are currently considered to be distinct clinical entities, both were found to be caused by de novo truncating sequence variants in the KAT6B (lysine acetyltransferase 6B) gene, strongly suggesting that they are allelic disorders. Herein, we report the clinical and genetic findings in a girl presenting with a serious multiple congenital anomaly syndrome with phenotypic features overlapping both SBBYSS and GTPTS; pointing out that the clinical distinction between these disorders is not exact and there do exist patients, in whom conventional clinical classification is problematic. Genetic analyses revealed a truncating c.4592delA (p.Asn1531Thrfs*18) variant in the last KAT6B exon. Our findings support that phenotypes associated with typical KAT6B disease-causing variants should be referred to as 'KAT6B spectrum disorders' or 'KAT6B related disorders', rather than their current SBBYSS and GTPTS classification.

Prenatal findings in children with early postnatal diagnosis of CHARGE syndrome.

CHARGE syndrome is a multiple congenital anomaly syndrome caused by mutations in CHD7. Diagnostic criteria have been proposed to improve diagnosis in fetuses at clinicopathological survey, but no criteria exist for fetal diagnosis during pregnancy. We collected prenatal findings of 12 children with CHARGE syndrome diagnosed in the first 3 months and a CHD7 mutation. We retrieved data on prenatal ultrasound (US) follow-up, fetal supplementary investigations, and results of postnatal evaluation. Seven pregnancies were complicated by the identification of isolated or multiple congenital anomalies. CHARGE syndrome was suspected in three fetuses but could not be confirmed despite additional examinations. Retrospectively, several postnatal findings could have been seen if they had been specifically searched. Intrauterine growth restriction, previously proposed as an exclusion criterion, complicated two pregnancies and is thus compatible with the diagnosis. Diagnosis of CHARGE syndrome remains difficult during pregnancy. If the diagnosis of CHARGE syndrome is raised in utero, we suggest a careful US examination to identify typical external ears, choanal atresia, or microphthalmia. Fetal brain magnetic resonance imaging can be helpful, but a normal result does not exclude the diagnosis. When CHARGE syndrome is highly suspected, CHD7 molecular analysis must be proposed to confirm the diagnosis. © 2016 John Wiley & Sons, Ltd.