Search

De novo germline variants of the SRY-related HMG-box 11 gene (SOX11) have been reported to cause Coffin-Siris syndrome-9 (CSS-9), a rare congenital disorder associated with multiple organ malformations, including ear anomalies. Previous clinical and animal studies have found that intragenic pathogenic variant or haploinsufficiency in the SOX11 gene could cause inner ear malformation, but no studies to date have documented the external ear malformation caused by SOX11 deficiency. Here, we reported a Chinese male with unilateral microtia and bilateral sensorineural deafness who showed CSS-like manifestations, including dysmorphic facial features, impaired neurodevelopment, and fingers/toes malformations. Using trio-based whole-exome sequencing, a de novo missense variant in SOX11 (NM_003108.4: c.347A>G, p.Y116C) was identified and classified as pathogenic variant as per American College of Medical Genetics guidelines. Moreover, a systematic search of the literature yielded 12 publications that provided data of 55 SOX11 intragenic variants affecting various protein-coding regions of SOX11 protein. By quantitatively analyzing phenotypic spectrum information related to these 56 SOX11 variants (including our case), we found variants affecting different regions of SOX11 protein (high-mobility group [HMG] domain and non-HMG regions) appear to influence the phenotypic spectrum of organ malformations in CSS-9; variants altering the HMG domain were more likely to cause the widest range of organ anomalies. In summary, this is the first report of CSS with external ear malformation caused by pathogenic variant in SOX11, indicating that the SOX11 gene may be not only essential for the development of the inner ear but also critical for the morphogenesis of the external ear. In addition, thorough clinical examination is recommended for patients who carry pathogenic SOX11 variants that affect the HMG domain, as these variants may cause the widest range of organ anomalies underlying this condition., (© 2024 Wiley Periodicals LLC.)

Anorectal malformations (ARMs) represent a wide spectrum of congenital anomalies of the anus and rectum, of which more than half are syndromic. Their etiology is highly heterogeneous and still poorly understood. We report a 4-year-old girl who initially presented with an isolated ARM, and subsequently developed a global developmental delay as part of an ARID1B-related Coffin-Siris syndrome (CSS). A co-occurrence of ARMs and CSS in an individual by chance is unexpected since both diseases are very rare. A review of the literature enabled us to identify 10 other individuals with both CSS and ARMs. Among the ten individuals reported in this study, 8 had a variant in ARID1A, 2 in ARID1B, and 1 in SMARCA4. This more frequent than expected association between CSS and ARM indicates that some ARMs are most likely part of the CSS spectrum, especially for ARID1A-related CSS., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

To date 11 patients with Coffin-Siris syndrome type 7 (OMIM 618027) have been described since the first literature report. All reported patients carried de novo variants with presumed dominant negative effect, which localized in the PHD1/PHD2 domains of DPF2. Here we report on the first familial case of Coffin-Siris syndrome type 7. The index patient presented during the 1st year of life with failure to thrive and ectodermal anomalies. The genetic analysis using whole exome sequencing showed a likely pathogenic missense variant in the PHD1 region. The family analysis showed that the mother as well as the older brother of the index patient also carried the detected DPF2 variant in heterozygous state. The mother had a history of school difficulties but no history of failure to thrive and was overall mildly affected. The brother showed developmental delay with autistic features, ectodermal anomalies and overlapping morphologic features but did not have a history of growth failure problems. To our knowledge this is the first report of an inherited likely pathogenic variant in DPF2, underlining the variability of the associated phenotype as well as the importance of considering inherited DPF2 variants during the variant filtering strategy of whole exome data., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Introduction: Although the whole-exome sequencing (WES) approach has been widely used in clinic, many rare diseases with syndromic and nonsyndromic neurological manifestations remain undiagnosed. Coffin-Siris syndrome (CSS) is a rare autosomal dominant genetic disease characterized by neurodevelopmental delay. A suspected diagnosis can be made based on the typical CSS clinical features; however, molecular genetic testing is necessary for a confirmed diagnosis., Objectives: Three CSS-like patients with negative results in the WES and chromosomal microarray analysis (CMA) were recruited in this study., Methods: We used whole-genome sequencing (WGS) technology to sequence the peripheral blood of the three families. To further explore the possible pathogenesis of CSS, we performed RNA-sequencing (RNA-seq)., Results: WGS identified the three CSS patients were carrying de novo copy number variants of the ARID1B gene, which have not been reported before. RNA-seq identified 184 differentially expressed genes (DEGs), with 116 up-regulated and 68 down-regulated. Functional annotation of DEGs showed that two biological processes (immune response, chemokine activity) and two signaling pathways (cytokine-cytokine receptor interaction, chemokine activity) were highlighted. We speculated that ARID1B deficiency might trigger abnormal immune responses, which may be involved in the pathophysiologic mechanisms of CSS., Conclusion: Our research provided further support for WGS application in CSS diagnosis and made an investigational approach for the underlying mechanisms of CSS., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

Coffin-Siris syndrome (CSS) 6 is caused by heterozygous pathogenic variants in the AT-rich interaction domain 2 (ARID2) gene on 12q12. Currently, only 26 cases with both detailed clinical and genetic information have been documented in the literature. Microdeletions of the entire ARID2 gene are rare. In this study, we report a 5-year-7-month-old Chinese female who underwent whole-exome sequencing to discover that she had a de novo 1.563 Mb heterozygous copy number loss at 12q12q13.11, involving an entire deletion of ARID2. The female had severe short stature with obvious dysmorphic facial features, global developmental delay and hypoplastic fingers and toes. Her growth hormone level was normal, with reduced IGF-1 and increased CA19-9 levels. After a review of the 27 patients with ARID2 deficiency, a significant positive correlation was observed between age and height standard deviation score (SDS) (r = 0.71, p = 0.0002), suggesting a possibility of growth catch-up. This study expands the genetic and phenotypic spectrum of CCS6 and provides a decision-making reference for growth hormone therapy., (© 2023 Wiley Periodicals LLC.)

Coffin-Siris syndrome (CSS, MIM135900) is a rare multiple congenital anomaly syndrome caused by pathogenic variants in the BAF complex; up to 28% of patients have previously been reported to have seizures, however, a comprehensive review of epilepsy has not been undertaken in this population. The International CSS Patient Report Database was queried for patients with self-reported seizures, epilepsy, and EEG results. Data gathered included demographic data, pathogenic gene variants, seizure characteristics and treatments, and EEG findings. In addition, a PubMed search was performed using keywords "Coffin-Siris syndrome" and "epilepsy," "seizures," or "EEG." Results from relevant papers are reported. Twenty-four (7.2%) of 334 patients in the database reported having seizures, EEG abnormalities, and/or epilepsy. Median age of seizure onset was 2. 7 years. Fifteen of the 23 patients with seizures or epilepsy had an ARID1B causative variant. Seventeen patients (5.1%) reported EEG abnormalities, the majority of which were described as focal or multifocal (87.5%). In all but one patient, seizures were controlled on antiseizure medications (ASMs). The literature review yielded 311 unique CSS patients, 82 of which (26.4%) carried diagnoses of seizures or epilepsy. Details on seizure type(s), EEG findings, and response to treatment were limited., (© 2022 Wiley Periodicals LLC.)

Pathogenic variants in SMARCA4 cause Coffin-Siris syndrome (CSS) while those in SMAD6 lead to aortic valve disease and other dysmorphisms. We identified a 6-year-old Thai boy with features of CSS alongside unusual manifestations including, very severe coarctation of the aorta (CoA) requiring coarctectomy in the neonatal period and bilateral radioulnar synostoses. Trio exome sequencing revealed that the patient harbored two de novo variants, a missense c.2475G > T, p.(Trp825Cys) in SMARCA4 and a nonsense c.652C > T, p.(Gln218Ter) in SMAD6. Both of which have never been previously reported. The clinical presentations in our patient are a result of the combinational features of each genetic variant: the SMARCA4 p.(Trp825Cys) variant leads to facial features of Coffin Siris syndrome and Dandy-Walker malformation, while the SMAD6 p.(Gln218Ter) variant underlies radioulnar synostosis. Interestingly, the severity of CoA in the proband is beyond the phenotypic spectra of each genetic variant and may be a result of the synergistic effects of both variants. Here, we report a child with variants in SMARCA4 or SMAD6 with combined features of each plus a severe CoA, possibly due to an additive effect of each variant., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2022 Elsevier Masson SAS. All rights reserved.)

Background: Coffin-Siris syndrome (CSS) is a rare congenital syndrome characterized by developmental delay, intellectual disability, microcephaly, coarse face and hypoplastic nail of the fifth digits. Heterozygous variants of different BAF complex-related genes were reported to cause CSS, including ARID1A and SMARCA4. So far, no CSS patients with ARID1A and SMARCA4 variants have been reported in China., Objective: The aim of the current study was to identify the causes of two Chinese patients with congenital growth deficiency and intellectual disability., Methods: Genomic DNA was extracted from the peripheral venous blood of patients and their family members. Genetic analysis included whole-exome and Sanger sequencing. Pathogenicity assessments of variants were performed according to the guideline of the American College of Medical Genetics and Genomics. The phenotypic characteristics of all CSS subtypes were summarized through literature review., Results: We identified two Chinese CSS patients carrying novel variants of ARID1A and SMARCA4 respectively. The cases presented most core symptoms of CSS except for the digits involvement. Additionally, we performed a review of the phenotypic characteristics in CSS, highlighting phenotypic varieties and related potential causes., Conclusions: We reported the first Chinese CSS2 and CSS4 patients with novel variants of ARID1A and SMARCA4. Our study expanded the genetic and phenotypic spectrum of CSS, providing a comprehensive overview of genotype-phenotype correlations of CSS., (© 2022. The Author(s) under exclusive licence to The Genetics Society of Korea.)

Ciliopathies represent a disease class characterized by a broad range of phenotypes including polycystic kidneys and skeletal anomalies. Ciliopathic skeletal phenotypes are among the most common and most difficult to treat due to a poor understanding of the pathological mechanisms leading to disease. Using an avian model (talpid2) for a human ciliopathy with both kidney and skeletal anomalies (orofaciodigital syndrome 14), we identified disruptions in the FGF23-PTH axis that resulted in reduced calcium uptake in the developing mandible and subsequent micrognathia. Although pharmacological intervention with the U.S. Food and Drug Administration (FDA)-approved pan-FGFR inhibitor AZD4547 alone rescued expression of the FGF target SPRY2, it did not significantly rescue micrognathia. In contrast, treatment with a cocktail of AZD4547 and teriparatide acetate, a PTH agonist and FDA-approved treatment for osteoporosis, resulted in molecular, cellular and phenotypic rescue of ciliopathic micrognathia in talpid2 mutants. Together, these data provide novel insight into pathological molecular mechanisms associated with ciliopathic skeletal phenotypes and a potential therapeutic strategy for a pleiotropic disease class with limited to no treatment options., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2022. Published by The Company of Biologists Ltd.)

Here we report for the first time on the maternal transmission of mild Coffin-Siris syndrome (CSS) caused by a SOX11 missense variant. We present two sisters with intellectual disability and muscular hypotonia born to non-consanguineous parents. Cogan ocular motor apraxia was present in both sisters. Body measurements were in a normal range. The mother and both daughters showed hypoplastic nails of the fifth toes. A missense variant in SOX11 [c.139 G > A; p.(Gly47Ser)] in both sisters and their mother was identified. Since 2014, variants in SOX11 are known to cause mild CSS. Most described patients showed intellectual disability, especially concerning acquired language. All of them had hypoplastic nails of the fifth toes. It is of note, that some of these patients show Cogan ocular motor apraxia. The facial dysmorphic features seem not to be specific. We suggest that the combination of Cogan ocular motor apraxia, hypoplastic nails of fifth toes, and developmental delay give the important diagnostic clue for a variant in the SOX11 gene (OMIM 615866, MR 27)., (© 2021. The Author(s).)

Auriculocondylar syndrome (ARCND) is an autosomal monogenic disorder characterised by external ear abnormalities and micrognathia due to hypoplasia of the mandibular rami, condyle and coronoid process. Genetically, three subtypes of ARCND (ARCND1, ARCND2 and ARCND3) have been reported. To date, five pathogenic variants of GNAI3 have been reported in ARCND1 patients. Here, we report a novel variant of GNAI3 (NM_006496:c.807C>A:p.(Asn269Lys)) in a Japanese girl with micrognathia using trio-based whole exome sequencing analysis. The GNAI3 gene encodes a heterotrimeric guanine nucleotide-binding protein. The novel variant locates the guanine nucleotide-binding site, and the substitution was predicted to interfere with guanine nucleotide-binding by in silico structural analysis. Three-dimensional computer tomography scan, or cephalogram, displayed severely hypoplastic mandibular rami and fusion to the medial and lateral pterygoid plates, which have been recognised in other ARCND1 patients, but have not been described in ARCND2 and ARCND3, suggesting that these may be distinguishable features in ARCND1., (© 2021. The Author(s).)

Coffin-Siris syndrome (CSS, MIM 135900) is a multi-system intellectual disability syndrome characterized by classic dysmorphic features, developmental delays, and organ system anomalies. Genes in the BRG1(BRM)-associated factors (BAF, Brahma associated factor) complex have been shown to be causative, including ARID1A , ARID1B , ARID2 , DPF2 , SMARCA4 , SMARCB1 , SMARCC2 , SMARCE1 , SOX11 , and SOX4 . In order to describe more robust genotype-phenotype correlations, we collected data from 208 individuals from the CSS/BAF complex registry with pathogenic variants in seven of these genes. Data were organized into cohorts by affected gene, comparing genotype groups across a number of binary and quantitative phenotypes. We determined that, while numerous phenotypes are seen in individuals with variants in the BAF complex, hypotonia, hypertrichosis, sparse scalp hair, and hypoplasia of the distal phalanx are still some of the most common features. It has been previously proposed that individuals with ARID -related variants are thought to have more learning and developmental struggles, and individuals with SMARC -related variants, while they also have developmental delay, tend to have more severe organ-related complications. SOX -related variants also have developmental differences and organ-related complications but are most associated with neurodevelopmental differences. While these generalizations still overall hold true, we have found that all individuals with BAF-related conditions are at risk of many aspects of the phenotype, and management and surveillance should be broad.

Loss-of-function mutations in chromatin remodeler gene ARID1A are a cause of Coffin-Siris syndrome, a developmental disorder characterized by dysgenesis of corpus callosum. Here, we characterize Arid1a function during cortical development and find unexpectedly selective roles for Arid1a in subplate neurons (SPNs). SPNs, strategically positioned at the interface of cortical gray and white matter, orchestrate multiple developmental processes indispensable for neural circuit wiring. We find that pancortical deletion of Arid1a leads to extensive mistargeting of intracortical axons and agenesis of corpus callosum. Sparse Arid1a deletion, however, does not autonomously misroute callosal axons, implicating noncell-autonomous Arid1a functions in axon guidance. Supporting this possibility, the ascending axons of thalamocortical neurons, which are not autonomously affected by cortical Arid1a deletion, are also disrupted in their pathfinding into cortex and innervation of whisker barrels. Coincident with these miswiring phenotypes, which are reminiscent of subplate ablation, we unbiasedly find a selective loss of SPN gene expression following Arid1a deletion. In addition, multiple characteristics of SPNs crucial to their wiring functions, including subplate organization, subplate axon-thalamocortical axon cofasciculation ("handshake"), and extracellular matrix, are severely disrupted. To empirically test Arid1a sufficiency in subplate, we generate a cortical plate deletion of Arid1a that spares SPNs. In this model, subplate Arid1a expression is sufficient for subplate organization, subplate axon-thalamocortical axon cofasciculation, and subplate extracellular matrix. Consistent with these wiring functions, subplate Arid1a sufficiently enables normal callosum formation, thalamocortical axon targeting, and whisker barrel development. Thus, Arid1a is a multifunctional regulator of subplate-dependent guidance mechanisms essential to cortical circuit wiring., Competing Interests: The authors declare no competing interest.

Disruption of the initiation of DNA replication is significantly associated with Meier-Gorlin syndrome (MGORS), an autosomal recessive condition of reduced growth, microtia and patellar a/hypoplasia. Biallelic mutations in CDC45, a member of the pre-initiation complex in DNA replication, cause a spectrum of phenotypes ranging from MGORS with craniosynostosis, through to isolated short stature and craniosynostosis. Here we report two affected sibs with MGORS and craniosynostosis, with biallelic variants in CDC45 identified by 10X Chromium whole genome sequencing. One variant is a frameshift mutation, predicted to be pathogenic, and is inherited in trans with a synonymous variant in a non-canonical exon (exon 7) of CDC45. An in vitro splicing assay showed that while the canonical CDC45 exon 6-exon 8 transcript (with skipping of exon 7; numbering as per NM001178010.2) remained as the predominant transcript, the variant allele induced the use of novel splice acceptor sites in intron 6, all of which produced transcripts harbouring premature stop codons. This perturbation of canonical splicing provides evidence that this synonymous variant is indeed a deleterious alteration in this family. This report adds to the initial patient cohort in which several synonymous variants were also described, further highlighting the contribution of this variant type in CDC45. It also reiterates the true potential pathogenicity of synonymous variants, which is a mutation type that is commonly ignored in variant prioritization strategies., (Copyright © 2021 Elsevier Masson SAS. All rights reserved.)

The structure of proline prevents it from adopting an optimal position for rapid protein synthesis. Poly-proline-tract (PPT) associated ribosomal stalling is resolved by highly conserved eIF5A, the only protein to contain the amino acid hypusine. We show that de novo heterozygous EIF5A variants cause a disorder characterized by variable combinations of developmental delay, microcephaly, micrognathia and dysmorphism. Yeast growth assays, polysome profiling, total/hypusinated eIF5A levels and PPT-reporters studies reveal that the variants impair eIF5A function, reduce eIF5A-ribosome interactions and impair the synthesis of PPT-containing proteins. Supplementation with 1 mM spermidine partially corrects the yeast growth defects, improves the polysome profiles and restores expression of PPT reporters. In zebrafish, knockdown eif5a partly recapitulates the human phenotype that can be rescued with 1 µM spermidine supplementation. In summary, we uncover the role of eIF5A in human development and disease, demonstrate the mechanistic complexity of EIF5A-related disorder and raise possibilities for its treatment.

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., (© 2020 Wiley Periodicals LLC.)

Mosaic genetic mutations may be somatic, germline, or "gonosomal" and have the potential to cause genetic syndromes, disorders, or malformations. Mutations can occur at any point in embryonic development and the timing determines the extent of distribution of the mutation throughout the body and different tissue types. The eye and visual pathway offer a unique opportunity to study somatic and gonosomal mosaic mutations as the eye consists of tissues derived from all three germ layers allowing disease pathology to be assessed with noninvasive imaging. In this review, we describe systemic and ocular manifestations in a child with mosaic Coffin-Siris syndrome. The patient presented with a significant medical history of accommodative esotropia and hyperopia, macrocephaly, polydactyly, global developmental delay, hypotonia, ureteropelvic junction (UPJ) obstruction, and brain MRI abnormalities. The ophthalmic findings in this patient were nonspecific, however, they are consistent with ocular manifestations reported in other patients with Coffin-Siris syndrome. We also review ophthalmic findings of select mosaic chromosomal and single-gene disorders. Ophthalmic assessment alongside clinical genetic testing may play an important role in diagnosis of genetic syndromes as well as understanding disease pathology, particularly when mosaicism plays a role., (© 2020 Wiley Periodicals LLC.)

Variants in the FIG4 gene, which encodes a phosphatidylinositol-3,5-bisphosphatase lead to obstruction of endocytic trafficking, causing accumulation of enlarged vesicles in murine peripheral neurons and fibroblasts. Bi-allelic pathogenic variants in FIG4 are associated with neurological disorders including Charcot-Marie-Tooth disease type-4J (CMT4J) and Yunis-Varón syndrome (YVS). We present four probands from three unrelated families, all homozygous for a recurrent FIG4 missense variant c.506A>C p.(Tyr169Ser), with a novel phenotype involving features of both CMT4J and YVS. Three presented with infant-onset dystonia and one with hypotonia. All have depressed lower limb reflexes and distal muscle weakness, two have nerve conduction studies (NCS) consistent with severe sensorimotor demyelinating peripheral neuropathy and one had NCS showing patchy intermediate/mildly reduced motor conduction velocities. All have cognitive impairment and three have swallowing difficulties. MRI showed cerebellar atrophy and bilateral T2 hyperintense medullary swellings in all patients. These children represent a novel clinicoradiological phenotype and suggest that phenotypes associated with FIG4 missense variants do not neatly fall into previously described diagnoses but can present with variable features. Analysis of this gene should be considered in patients with central and peripheral neurological signs and medullary radiological changes, providing earlier diagnosis and informing reproductive choices., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The chromatin remodeling AT-Rich interaction domain containing 1B protein (ARID1B) also known as BAF-associated factor, 250-KD, B (BAF250B) codified by the ARID1B gene (MIM#614556), is a small subunit of the mammalian SWI/SNF or BAF complex, an ATP-dependent protein machinery which is able to activate or repress gene transcription, allowing protein access to histones through DNA relaxed conformation. ARID1B gene mutations have been associated with two hereditary syndromic conditions, namely Coffin-Siris (CSS, MIM#135900) and Nicolaides-Baraitser syndromes (NCBRS, MIM#601358), characterized by neurodevelopment delay, craniofacial dysmorphisms and skeletal anomalies. Furthermore, intellectual impairment and central nervous system (CNS) alterations, comprising abnormal corpus callosum, have been associated with mutations in this gene. Moreover, ARID1B anomalies resulted to be involved in neoplastic events and Hirschprung disease. Here we report on two monozygotic male twins, displaying clinical appearance strikingly resembling NCBRS and CSS phenotype, who resulted carriers of a novel 6q25.3 microdeletion, encompassing only part of the ARID1B gene. The deleted segment was not inherited from the only parent tested and afflicted the first exons of the gene, coding for protein disordered region. We also provide, for the first time, a review of previously published ARID1B mutated patients with NCBRS and CSS phenotype and a computer-assisted dysmorphology analysis of NCBRS and ARID1B related CSS individuals, through the Face2Gene suite, confirming the existence of highly overlapping facial gestalt of both conditions. The present findings indicate that ARID1B could be considered a contributing gene not only in CSS but also in NCBRS phenotype, although the main gene related to this latter condition is the SMARCA2 gene (MIM#600014), another component of the BAF complex. So, ARID1B study should be considered in such individuals., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)

Coffin-Siris Syndrome (CSS) is a rare neurodevelopmental disorder characterized by intellectual disability, coarse facial features, hypoplastic digits/nails, and hypertrichosis. The genes causative of CSS mainly encode the SWI/SNF complex, which contributes to chromatin remodeling and regulates the access of transcriptional factors to specific gene sites. While ARID1B mutations account for a third of all CSS cases, the condition's phenotypic features vary widely. We document the case of a girl with CSS who presented with a variant facial appearance, global developmental delay with speech impairment, agenesis of the corpus callosum, funnel chest, and bilateral renal stones without hypertrichosis or hypoplasia of the fifth fingernail. Genetic analysis revealed that the patient had a novel heterozygous frameshift mutation c.2201dupG (p.Ser736Ilefs*27) on the ARID1B gene., (© 2020 by the Association of Clinical Scientists, Inc.)

Micrognathia is a common craniofacial deformity which represents hypoplastic development of the mandible, accompanied by retrognathia and consequent airway problems. Usually, micrognathia is accompanied by multiple systematic defects, known as syndromic micrognathia, and is in close association with genetic factors. Now, large quantities of pathogenic genes of syndromic micrognathia have been revealed. However, how these different pathogenic genes could lead to similar phenotypes, and whether there are some common characteristics among these pathogenic genes are still unknown. In this study, we proposed a genetic-phenotypic classification of syndromic micrognathia based on pathogenic genes information obtained from Phenolyzer, DAVID, OMIM, and PubMed database. Pathogenic genes of syndromic micrognathia could be divided into four groups based on gene function, including cellular processes and structures, cell metabolism, cartilage and bone development, and neuromuscular function. In addition, these four groups exhibited various clinical characteristics, and the affected systems, such as central nervous system, skeletal system, cardiovascular system, oral and dental system, respiratory system and muscle, were different in these four groups. This classification could provide meaningful insights into the pathogenesis of syndromic micrognathia, and offer some clues for understanding the molecular mechanism, as well as guiding precise clinical diagnosis and treatment for syndromic micrognathia.

Coffin-Siris syndrome (CSS) is a developmental disability, caused by genomic variants in the gene SMARCA4 , in addition to other known genes, but the full spectrum of SMARCA4 variants that can cause CSS is unknown with 40% of cases not having molecular confirmation. In this report, we identify a patient with CSS, a severe cardiac phenotype, and a novel SMARCA4 variant. There is no experimental structure of human SMARCA4, so we use molecular modeling techniques to generate a structural model of human SMARCA4. We then map known SMARCA4 variants causative of CSS and our novel variant to the model. We use the resulting information to support the interpretation that the novel variant is causative of disease in our patient. Modeling demonstrates that the variant found in our patient is in a region of SMARCA4 associated with DNA binding, as are the other known pathogenic SMARCA4 variants mapped. Because of this structural information, we discuss how these variants may be disease-causing through a dominant negative effect of disrupting DNA binding., (© 2019 Dsouza et al.; Published by Cold Spring Harbor Laboratory Press.)

Background: Coffin-Siris syndrome (CSS) is characterized by intellectual disability, dysmorphic facial features, growth deficiency, microcephaly, and abnormalities of the fifth fingers/toes. CSS is caused by mutations in several genes of the BRG1-associated factor pathway including SMARCA4., Methods: Whole-exome sequencing was performed on a 14-year-old female individual who presented with mild intellectual disability and dysmorphic features, tooth abnormalities, and short stature. She had brachydactyly but no aplasia or hypoplasia of the distal phalanx or nail of the fifth digit. She was also found to have retinal dystrophy that has not been previously reported in CSS., Results: The individual presented herein was found to harbor a previously unreported de novo variant in SMARCA4., Conclusion: This case expands the phenotypic spectrum of CSS manifestations., (© 2019 Telethon Foundation. Molecular Genetics & Genomic Medicine published by Wiley Periodicals, Inc.)

In the last 3 years de novo sequence variants in the ARID2 (AT-rich interaction domain 2) gene, a subunit of the SWI/SNF complex, have been linked to intellectual disabilities in 3 case reports including one which describes frameshift mutations in ARID2 in 2 patients with features resembling Coffin-Siris syndrome. Coffin-Siris syndrome (CSS) is a rare congenital syndrome characterized by intellectual deficit, coarse facial features and hypoplastic or absent fifth fingernails and/or toenails among other features. Mutations in a number of different genes encoding SWI/SNF chromatin remodelling complex proteins have been described but the underlying molecular cause remains unknown in approximately 40% of patients with CSS. Here we describe 7 unrelated individuals, 2 with deletions of the ARID2 region and 5 with de novo truncating mutations in the ARID2 gene. Similarities to CSS are evident. Although hypertrichosis and hypoplasia of the fifth finger nail and distal phalanx do not appear to be common in these patients, toenail hypoplasia and the presence of Wormian bones might support the involvement of ARID2., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

Objective: To investigate the intraobserver and interobserver reproducibility of a novel sonographic parameter named facial maxillary angle (FMA) and to establish nomograms of FMA, inferior facial angle (IFA), frontal nasal-mental angle (FNMA), maxilla-nasion-mandible angle (MNMA), and fetal profile line (FPL) in Chinese fetuses., Methods: In this prospective cross-sectional study, FMA, IFA, FNMA, MNMA, and FPL were measured in 592 normal fetuses between 16 and 36 gestational weeks. FMA was measured twice by the same and another operator with a blinded method on the first 50 cases. The reference interval was defined as ±2SD. The efficacy of five sonographic markers was tested in 10 fetuses with micrognathia retrieved from the database of our unit., Results: The intraclass correlation coefficient (95% CI) of intraobserver and interobserver reproducibility of FMA was 0.937 (0.890-0.964) and 0.891 (0.809-0.938), respectively. FMA, FNMA, and IFA increased slightly from 16 weeks till 28-31 weeks and decreased minimally thereafter. FMA and FNMA made correct diagnosis in all affected fetuses; MNMA and IFA identified nine and eight cases respectively, and FPL only detected five cases., Conclusion: A fixed cutoff of 66° for FMA and 136° for FNMA may be adopted as simple screening criteria of micrognathia., (© 2018 John Wiley & Sons, Ltd.)

Cerebral cavernous malformation (CCM) is a common cerebrovascular disease that can occur sporadically or be inherited. They are major causes of stroke, cerebral hemorrhage, and neurological deficits in the younger population. Loss-of-function mutations in three genes, CCM1 , CCM2 , and CCM3 , have been identified as the cause of human CCMs. Currently, no drug is available to treat CCM disease. Hyperactive mitogen-activated protein kinase kinase Kinase 3 (MEKK3) kinase signaling as a consequence of loss of CCM genes is an underlying cause of CCM lesion development. Using a U.S. Food and Drug Administration-approved kinase inhibitor library combined with virtual modeling and biochemical and cellular assays, we have identified a clinically approved small compound, ponatinib, that is capable of inhibiting MEKK3 activity and normalizing expression of downstream kruppel-like factor (KLF) target genes. Treatment with this compound in neonatal mouse models of CCM can prevent the formation of new CCM lesions and reduce the growth of already formed lesions. At the ultracellular level, ponatinib can normalize the flattening and disorganization of the endothelium caused by CCM deficiency. Collectively, our study demonstrates ponatinib as a novel compound that may prevent CCM initiation and progression in mouse models through inhibition of MEKK3-KLF signaling.

Coffin-Siris syndrome (CSS; MIM 135900) is a multisystem congenital anomaly syndrome caused by mutations in the genes in the Brg-1 associated factors (BAF) complex. Classically, individuals with CSS have been described with hypo- or aplasia of the fifth digit nails or phalanges (hence the term "fifth digit syndrome"). Other physical features seen include growth restriction, coarse facial features, hypertrichosis or hirsutism, sparse scalp hair, dental anomalies, and other organ-system abnormalities. Varying degrees of developmental and intellectual delay are universal. To date, approximately 200 individuals have been described in the literature. With the advent of large-scale genetic testing such as whole-exome sequencing is becoming more available, more individuals are being found to have mutations in this pathway, and the phenotypic spectrum appears to be broadening. We report here a large cohort of 81 individuals with the diagnosis of CSS from the first parent-reported CSS/BAF complex registry in an effort to describe this variation among individuals, the natural history of the syndrome, and draw some gene-phenotype correlations. We propose that changes in the BAF complex may represent a spectrum of disorders, including both ARID1B-related nonsyndromic intellectual disability (ARID1B-ID) and CSS with classic physical features. In addition, we offer surveillance and management recommendations based on the medical issues encountered in this cohort to help guide physicians and patients' families., (© 2018 Wiley Periodicals, Inc.)

In order to lead to insights and discussion on proper use of Orthodontics and Pathology-related terminology, particularly in cases of smaller-than-usual maxilla and mandible - that is, anomalous ones -, this study compared the conceptual meaning of the term "atresia." It is considered improper when referring to maxilla and mandible with deficient growth compared to development that is satisfactory enough to reach normal size. To identify smaller maxilla and mandible, the most proper and accurate term is hypoplastic maxilla or mandible. This is because "atresia" stands for an anomaly related to lumen blockage in hollow organs, which is not the case for neither maxilla nor mandible. Hypoplastic maxilla or mandible can be properly and specifically referred to as micrognathia.

Germline variants that affect function are found in seven genes of the BAF chromatin-remodeling complex. They are linked to a broad range of diseases that, according to the gene affected, range from non-syndromic or syndromic neurodevelopmental disorders to low-grade tumors and malignancies. In the current meta-analysis, we evaluate genetic and clinical data from more than 400 families and 577 patients affected by BAF germline alterations. We focus on SMARCB1, including 43 unpublished patients from the EU-RHAB registry and our institution. For this gene, we further demonstrate whole gene as well as exon deletions and truncating variants to be associated with malignancy and early-onset disease. In contrast, non-truncating variants are associated with non-malignant disorders, such as Coffin-Siris syndrome or late-onset tumors like schwannoma or meningioma (p < 0.0001). SMARCB1 germline variants are distributed across the gene with variants in exons 1, 2, 8, and 9 being associated with low-grade entities, and single-nucleotide variants or indels outside of exon 9 that appear in patients with malignancies (p < 0.001). We attribute variants in specific BAF genes to certain disease entities. Finally, single-nucleotide variants and indels are sometimes detected in the healthy relatives of tumor patients, while Coffin-Siris syndrome and Nicolaides-Baraitser syndrome generally seem to appear de novo. Our findings add further information on the genotype-phenotype association of germline variants detected in genes of the BAF complex. Functional studies are urgently needed for a deeper understanding of BAF-related disorders and may take advantage from the comprehensive information gathered in this article.

We present a 4-year-old girl with delayed neuromotor development, short stature of prenatal onset, and specific behavioral and craniofacial features harboring an intragenic deletion in the ARID2 gene. The phenotype confirmed the major features of the recently described ARID2-related intellectual disability syndrome. However, our patient showed overlapping features with Nicolaides-Baraitser syndrome and Coffin-Siris syndrome, providing further arguments to reclassify these disorders as "SWI/SNF-related intellectual disability syndromes.", (© 2017 Wiley Periodicals, Inc.)

Auriculocondylar syndrome, mainly characterized by micrognathia, small mandibular condyle, and question mark ears, is a rare disease segregating in an autosomal dominant pattern in the majority of the families reported in the literature. So far, pathogenic variants in PLCB4, GNAI3, and EDN1 have been associated with this syndrome. It is caused by a developmental abnormality of the first and second pharyngeal arches and it is associated with great inter- and intra-familial clinical variability, with some patients not presenting the typical phenotype of the syndrome. Moreover, only a few patients of each molecular subtype of Auriculocondylar syndrome have been reported and sequenced. Therefore, the spectrum of clinical and genetic variability is still not defined. In order to address these questions, we searched for alterations in PLCB4, GNAI3, and EDN1 in patients with typical Auriculocondylar syndrome (n = 3), Pierre Robin sequence-plus (n = 3), micrognathia with additional craniofacial malformations (n = 4), or non-specific auricular dysplasia (n = 1), which could represent subtypes of Auriculocondylar syndrome. We found novel pathogenic variants in PLCB4 only in two of three index patients with typical Auriculocondylar syndrome. We also performed a detailed comparative analysis of the patients presented in this study with those previously published, which showed that the pattern of auricular abnormality and full cheeks were associated with molecularly characterized individuals with Auriculocondylar syndrome. Finally, our data contribute to a better definition of a set of parameters for clinical classification that may be used as a guidance for geneticists ordering molecular testing for Auriculocondylar syndrome. © 2017 Wiley Periodicals, Inc., (© 2017 Wiley Periodicals, Inc.)

Purpose: Newborns with Pierre Robin sequence (PRS) and syndromic micrognathia show microgenia and glossoptosis, which cause reduction of the airway and breathing difficulty from birth. Our goal is to analyze quantitative and qualitative volumetric changes before and after fast and early mandibular osteodistraction (FEMOD) and to compare radiological data., Methods: The sample was composed of 4 patients, who satisfied inclusion criteria for completeness of data. Computed tomography pre- and post-operation were performed, then a volumetric assessment was made with Dolphin Imaging. Polysomnography was performed before and after FEMOD., Results: Pre- and post-operative CT scan data were compared. The analysis of all three sections showed a significant increase of volumetric parameters. The retroglossal volume average increase was 346%, and the retropalatal volume average increase was 169%. These data matched the improvement recorded by polysomnography., Conclusions: The data confirm FEMOD as an efficient treatment to improve airways and breathing problem in patients affected by Pierre Robin sequence and syndromic micrognathia. The three-dimensional volume rendering could be a useful method to evaluate and quantify the increase in airways volume., (Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

The gene encoding the AT-rich interaction domain-containing protein 1B (ARID1B) has recently been shown to be one of the most frequently mutated genes in patients with intellectual disability (ID). The phenotypic spectrums associated with variants in this gene vary widely ranging for mild to severe non-specific ID to Coffin-Siris syndrome. In this study, we evaluated three children from a consanguineous Emirati family affected with ID and dysmorphic features. Genomic DNA from all affected siblings was analyzed using CGH array and whole-exome sequencing (WES). Based on a recessive mode of inheritance, homozygous or compound heterozygous variants shared among all three affected children could not be identified. However, further analysis revealed a heterozygous variant (c.4318C>T; p.Q1440*) in the three affected children in an autosomal dominant ID causing gene, ARID1B. This variant was absent in peripheral blood samples obtained from both parents and unaffected siblings. Therefore, we propose that the most likely explanation for this situation is that one of the parents is a gonadal mosaic for the variant. To the best of our knowledge, this is the first report of a gonadal mosaicism inheritance of an ARID1B variant leading to familial ID recurrence., (© 2015 Wiley Periodicals, Inc.)

We report a patient with a constitutional missense mutation in SMARCB1, Coffin-Siris Syndrome (CSS), and schwannomatosis. CSS is a rare congenital syndrome with characteristic clinical findings. This thirty-three-year-old man was diagnosed early in life with the constellation of moderate intellectual disability, hypotonia, mild microcephaly, coarse facies, wide mouth with full lips, hypoplasia of the digits, and general hirsutism. At age 26, he was found to have schwannomatosis after presenting with acute spinal cord compression. Blood and tissue analysis of multiple subsequent schwannoma resections revealed a germline missense mutation of SMARCB1, acquired loss of 22q including SMARCB1 and NF2 and mutation of the remaining NF2 wild-type allele-thus completing the four-hit, three-event mechanism associated with schwannomatosis. Variations in five genes have been associated with the Coffin-Siris phenotype: ARID1A, ARID1B, SMARCA4, SMARCB1, and SMARCE1. Of these genes, SMARCB1 has a well-established association with schwannomatosis and malignancy. This is the first report of a patient with a constitutional missense mutation of SMARCB1 resulting in CSS and subsequent development of schwannomatosis. This finding demonstrates that a SMARCB1 mutation may be the initial "hit" (constitutional) for a genetic disorder with subsequent risk of developing schwannomas and other malignancies, and raises the possibility that other patients with switch/sucrose non-fermenting (SWI/SNF) mutations may be at increased risk for tumors., (© 2015 Wiley Periodicals, Inc.)

Impairment of brain endothelial barrier integrity is critical for cerebral cavernous malformation (CCM) lesion development. The current study investigates changes in tight junction (TJ) complex organization when PDCD10 (CCM3) is mutated/depleted in human brain endothelial cells. Analysis of lesions with CCM3 mutation and brain endothelial cells transfected with CCM3 siRNA (CCM3-knockdown) showed little or no increase in TJ transmembrane and scaffolding proteins mRNA expression, but proteins levels were generally decreased. CCM3-knockdown cells had a redistribution of claudin-5 and occludin from the membrane to the cytosol with no alterations in protein turnover but with diminished protein-protein interactions with ZO-1 and ZO-1 interaction with the actin cytoskeleton. The most profound effect of CCM3 mutation/depletion was on an actin-binding protein, cortactin. CCM3 depletion caused cortactin Ser-phosphorylation, dissociation from ZO-1 and actin, redistribution to the cytosol and degradation. This affected cortical actin ring organization, TJ complex stability and consequently barrier integrity, with constant hyperpermeability to inulin. A potential link between CCM3 depletion and altered cortactin was tonic activation of MAP kinase ERK1/2. ERK1/2 inhibition increased cortactin expression and incorporation into the TJ complex and improved barrier integrity. This study highlights the potential role of CCM3 in regulating TJ complex organization and brain endothelial barrier permeability.

Background and Purpose: The inverted-L osteotomy for mandibular distraction in Pierre Robin sequence (PRS) is a useful technique for avoiding injury to the tooth root and inferior alveolar nerve. Identification of the lingula is understudied and may decrease iatrogenic complications. This study aims to map the position of the lingula in the micrognathic mandible and compare the location of the lingula in relative normal mandible., Methods: This is a retrospective cohort study of symptomatic PRS patients. Three-dimensional CT scans were reviewed and the relative lingula position described., Results: The study includes 11 PRS patients and 4 controls. The average measurements were overjet 9.99 (PRS) versus 4.28 mm (control) (P = 0.001), vertical ramus height 16.05 versus 23.04 mm (P = 0.003), and width 15.16 versus 20.67 mm (P = 003); horizontal ramus length 26.58 versus 40.62 mm (P = 0.001), gonial angle 132.64° versus 123.5° (P = 0.018); horizontal lingula position 7.25 versus 10.75 mm (P = 0.001), vertical position 9.02 versus 11.34 mm (P = 0.026). The ratio along the x-axis in PRS was 0.44 versus 0.52 in controls (P = 0.138); along the y-axis, the ratio was 0.57 versus 0.49 (P = 0.078)., Conclusions: Compared to normal controls, overjet is greater, vertical ramus height and widths are lesser, horizontal ramus length is lesser, and the gonial angle is greater in PRS patients. When analyzed as proportions along the height and width of the vertical ramus, there is no statistical difference (P > 0.05) in the position of the lingula between PRS patients and normal controls.

This study describes a spontaneous case of Pierre Robin sequence in a nonhuman animal species. A miniature dachshund with micrognathia developed glossoptosis, respiratory distress, dysphagia, temporomandibular ankylosis, and a misaligned upper jaw. The severity of this condition resulted in death by obstructive apnea at the age of 8 mo. Dogs with Pierre Robin sequence can provide further knowledge and a greater understanding of this abnormality, leading to better management of affected individuals and improvement of therapeutic methods.

Robin sequence (RS) can be defined as the combination of micrognathia and upper airway obstruction/glossoptosis causing neonatal respiratory problems, with or without a cleft palate and either isolated or non-isolated. Pathogenesis varies widely. We hypothesize that optimal treatment depends on pathogenesis and therefore patients should be stratified according to diagnosis. Here, we evaluate diagnoses and (presumed) pathogeneses in an RS cohort. Medical records of all RS patients presenting between 1995-2013 in three academic hospitals were evaluated. Four clinical geneticists re-evaluated all information, including initial diagnosis. Diagnoses were either confirmed, considered uncertain, or rejected. If uncertain or rejected, patients were re-evaluated. Subsequent results were re-discussed and a final conclusion was drawn. We included 191 RS patients. After re-evaluation and changing initial diagnoses in 48 of the 191 patients (25.1%), 37.7% of the cohort had isolated RS, 8.9% a chromosome anomaly, 29.3% a Mendelian disorder, and 24.1% no detectable cause. Twenty-two different Mendelian disorders were diagnosed, of which Stickler syndrome was most frequent. Stratification of diagnoses according to (presumed) pathogenic mechanism in 73 non-isolated patients with reliable diagnoses showed 43.9% to have a connective tissue dysplasia, 5.5% a neuromuscular disorder, 47.9% a multisystem disorder, and 2.7% an unknown mechanism. We diagnosed more non-isolated RS patients compared to other studies. Re-evaluation changed initial diagnosis in a quarter of patients. We suggest standardized re-evaluation of all RS patients. Despite the relatively high diagnostic yield pathogenesis could be determined in only 59.7% (71/119), due to limited insight in pathogenesis in diagnosed entities. Further studies into pathogenesis of entities causing RS are indicated., (© 2015 Wiley Periodicals, Inc.)

Clinical phenotypes in individuals with a supernumerary marker chromosome (SMC) are mainly caused by gene dosage effects due to the genes located on the SMC. An additional effect may result from uniparental disomy (UPD). Consequently, the occurrence of UPD may be a confounding factor in identifying genotype-phenotype correlations in SMC syndromes. Here, we report on a patient that illustrates this problem; the phenotype of this patient was a consequence of a combined effect of gene dosage and UPD. The proband showed facial dysmorphisms, growth retardation and developmental delay. G-band karyotype of the proband's peripheral blood showed the presence of mosaic SMC. A SNP array analysis documented maternal UPD20 and 20p duplication. It is known that maternal UPD20 causes prenatal onset growth retardation and feeding difficulties. By contrast, duplication of 20p causes facial dysmorphisms, micrognathia, cleft palate, developmental delay and vertebral anomalies. Our classification of the proband's phenotype showed a mixture of these two effects. Therefore, we suggest the routine use of genome-wide SNP array towards the detailed genotype-phenotype correlations for SMC syndromes., (© 2015 Wiley Periodicals, Inc.)

Coffin-Siris syndrome (CSS) is a congenital disorder characterized by intellectual disability, growth deficiency, microcephaly, coarse facial features, and hypoplastic or absent fifth fingernails and/or toenails. We previously reported that five genes are mutated in CSS, all of which encode subunits of the switch/sucrose non-fermenting (SWI/SNF) ATP-dependent chromatin-remodeling complex: SMARCB1, SMARCA4, SMARCE1, ARID1A, and ARID1B. In this study, we examined 49 newly recruited CSS-suspected patients, and re-examined three patients who did not show any mutations (using high-resolution melting analysis) in the previous study, by whole-exome sequencing or targeted resequencing. We found that SMARCB1, SMARCA4, or ARID1B were mutated in 20 patients. By examining available parental samples, we ascertained that 17 occurred de novo. All mutations in SMARCB1 and SMARCA4 were non-truncating (missense or in-frame deletion) whereas those in ARID1B were all truncating (nonsense or frameshift deletion/insertion) in this study as in our previous study. Our data further support that CSS is a SWI/SNF complex disorder., (© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The Meier-Gorlin syndrome (MGS) or ear, patella, short stature syndrome (MIM #224690) is a rare disorder with bilateral microtia, aplasia or hypoplasia of the patellae and severe intra-uterine and post-natal growth retardation. We report the case of a 10-year-old male with MGS diagnosis, his parents were related, he also showed conductive hearing loss and maloclussion and long upper central incisors, more importantly he had asymmetry of the left cerebral hemisphere and ventricular system, his intelligence was normal. As far as we know, these abnormalities have not been previously described in patients with MGS and the present report corresponds to the first Mexican case described so far.

Chromatin remodeling complexes are known to modify chemical marks on histones or to induce conformational changes in the chromatin in order to regulate transcription. De novo dominant mutations in different members of the SWI/SNF chromatin remodeling complex have recently been described in individuals with Coffin-Siris (CSS) and Nicolaides-Baraitser (NCBRS) syndromes. Using a combination of whole-exome sequencing, NGS-based sequencing of 23 SWI/SNF complex genes, and molecular karyotyping in 46 previously undescribed individuals with CSS and NCBRS, we identified a de novo 1-bp deletion (c.677delG, p.Gly226Glufs*53) and a de novo missense mutation (c.914G>T, p.Cys305Phe) in PHF6 in two individuals diagnosed with CSS. PHF6 interacts with the nucleosome remodeling and deacetylation (NuRD) complex implicating dysfunction of a second chromatin remodeling complex in the pathogenesis of CSS-like phenotypes. Altogether, we identified mutations in 60% of the studied individuals (28/46), located in the genes ARID1A, ARID1B, SMARCB1, SMARCE1, SMARCA2, and PHF6. We show that mutations in ARID1B are the main cause of CSS, accounting for 76% of identified mutations. ARID1B and SMARCB1 mutations were also found in individuals with the initial diagnosis of NCBRS. These individuals apparently belong to a small subset who display an intermediate CSS/NCBRS phenotype. Our proposed genotype-phenotype correlations are important for molecular screening strategies.

Hypoglossia is referred to a small volume and/or size of the tongue. It is a rare congenital condition caused by failed embryogenesis of the lateral lingual swellings and tuberculum impar during the fourth to eighth weeks of gestation. The anomaly has often occurred in association with limb abnormalities and various syndromes, and it affects facial and mandibular growth. The present report describes a case of severe congenital hypoglossia in a female infant, her systemic and dentofacial features, and the initial management.