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Genes Jun 2021Coffin-Siris syndrome (CSS, MIM 135900) is a multi-system intellectual disability syndrome characterized by classic dysmorphic features, developmental delays, and organ...
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 , , , , , , , , , and . 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 -related variants are thought to have more learning and developmental struggles, and individuals with -related variants, while they also have developmental delay, tend to have more severe organ-related complications. -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.
Topics: Abnormalities, Multiple; Face; Genotype; Hand Deformities, Congenital; Humans; Intellectual Disability; Micrognathism; Mutation; Neck; Phenotype; Transcription Factors
PubMed: 34205270
DOI: 10.3390/genes12060937 -
Genetics in Medicine : Official Journal... Jun 2019Pathogenic variants in ARID1B are one of the most frequent causes of intellectual disability (ID) as determined by large-scale exome sequencing studies. Most studies...
PURPOSE
Pathogenic variants in ARID1B are one of the most frequent causes of intellectual disability (ID) as determined by large-scale exome sequencing studies. Most studies published thus far describe clinically diagnosed Coffin-Siris patients (ARID1B-CSS) and it is unclear whether these data are representative for patients identified through sequencing of unbiased ID cohorts (ARID1B-ID). We therefore sought to determine genotypic and phenotypic differences between ARID1B-ID and ARID1B-CSS. In parallel, we investigated the effect of different methods of phenotype reporting.
METHODS
Clinicians entered clinical data in an extensive web-based survey.
RESULTS
79 ARID1B-CSS and 64 ARID1B-ID patients were included. CSS-associated dysmorphic features, such as thick eyebrows, long eyelashes, thick alae nasi, long and/or broad philtrum, small nails and small or absent fifth distal phalanx and hypertrichosis, were observed significantly more often (p < 0.001) in ARID1B-CSS patients. No other significant differences were identified.
CONCLUSION
There are only minor differences between ARID1B-ID and ARID1B-CSS patients. ARID1B-related disorders seem to consist of a spectrum, and patients should be managed similarly. We demonstrated that data collection methods without an explicit option to report the absence of a feature (such as most Human Phenotype Ontology-based methods) tended to underestimate gene-related features.
Topics: Abnormalities, Multiple; Adolescent; Adult; Child; Child, Preschool; Chromosomal Proteins, Non-Histone; DNA-Binding Proteins; Exome; Face; Female; Genetic Association Studies; Genetic Variation; Hand Deformities, Congenital; Humans; Infant; Infant, Newborn; Intellectual Disability; Male; Micrognathism; Middle Aged; Mutation; Neck; Penetrance; Transcription Factors
PubMed: 30349098
DOI: 10.1038/s41436-018-0330-z -
Orphanet Journal of Rare Diseases Sep 2015Meier-Gorlin syndrome (MGS) is a rare autosomal recessive primordial dwarfism disorder, characterized by microtia, patellar applasia/hypoplasia, and a proportionate... (Review)
Review
Meier-Gorlin syndrome (MGS) is a rare autosomal recessive primordial dwarfism disorder, characterized by microtia, patellar applasia/hypoplasia, and a proportionate short stature. Associated clinical features encompass feeding problems, congenital pulmonary emphysema, mammary hypoplasia in females and urogenital anomalies, such as cryptorchidism and hypoplastic labia minora and majora. Typical facial characteristics during childhood comprise a small mouth with full lips and micro-retrognathia. During ageing, a narrow, convex nose becomes more prominent. The diagnosis MGS should be considered in patients with at least two of the three features of the clinical triad of microtia, patellar anomalies, and pre- and postnatal growth retardation. In patients with short stature and/or microtia, the patellae should be assessed with care by ultrasonography before age 6 or radiography thereafter. Mutations in one of five genes (ORC1, ORC4, ORC6, CDT1, and CDC6) of the pre-replication complex, involved in DNA-replication, are detected in approximately 67-78% of patients with MGS. Patients with ORC1 and ORC4 mutations appear to have the most severe short stature and microcephaly. Management should be directed towards in-depth investigation, treatment and prevention of associated problems, such as growth retardation, feeding problems, hearing loss, luxating patellae, knee pain, gonarthrosis, and possible pulmonary complications due to congenital pulmonary emphysema with or without broncho- or laryngomalacia. Growth hormone treatment is ineffective in most patients with MGS, but may be effective in patients in whom growth continues to decrease after the first year of life (usually growth velocity normalizes after the first year) and with low levels of IGF1. At present, few data is available about reproduction of females with MGS, but the risk of premature labor might be increased. Here, we propose experience-based guidelines for the regular care and treatment of MGS patients.
Topics: Abnormalities, Multiple; Congenital Microtia; Female; Growth Disorders; Humans; Male; Micrognathism; Patella; Urogenital Abnormalities
PubMed: 26381604
DOI: 10.1186/s13023-015-0322-x -
Journal of Ayub Medical College,... 2019Yunis-Varon syndrome is a rare autosomal recessive disorder with characteristic facial features and limb anomalies. We report a neonate born to consanguineously married...
Yunis-Varon syndrome is a rare autosomal recessive disorder with characteristic facial features and limb anomalies. We report a neonate born to consanguineously married normal parents with typical clinical and radiologic features of Yunis-Varon syndrome along with complete cleft lip and palate: an infrequent association. The family had two previous babies with similar features who died in infancy. This is a first reported case of Yunis-Varon syndrome in Pakistan.
Topics: Cleft Lip; Cleft Palate; Cleidocranial Dysplasia; Consanguinity; Ectodermal Dysplasia; Fatal Outcome; Female; Humans; Infant, Newborn; Limb Deformities, Congenital; Micrognathism; Pakistan
PubMed: 31094135
DOI: No ID Found -
Current Osteoporosis Reports Feb 2016The SOXC group of transcription factors, composed of SOX4, SOX11, and SOX12, has evolved to fulfill key functions in cell fate determination. Expressed in many types of... (Review)
Review
The SOXC group of transcription factors, composed of SOX4, SOX11, and SOX12, has evolved to fulfill key functions in cell fate determination. Expressed in many types of progenitor/stem cells, including skeletal progenitors, SOXC proteins potentiate pathways critical for cell survival and differentiation. As skeletogenesis unfolds, SOXC proteins ensure cartilage primordia delineation by amplifying canonical WNT signaling and antagonizing the chondrogenic action of SOX9 in perichondrium and presumptive articular joint cells. They then ensure skeletal elongation by inducing growth plate formation via enabling non-canonical WNT signaling. Human studies have associated SOX4 with bone mineral density and fracture risk in osteoporotic patients, and SOX11 with Coffin-Siris, a syndrome that includes skeletal dysmorphism. Meanwhile, in vitro and mouse studies have suggested important cell-autonomous roles for SOXC proteins in osteoblastogenesis. We here review current knowledge and gaps in understanding of SOXC protein functions, with an emphasis on the skeleton and possible links to osteoporosis.
Topics: Abnormalities, Multiple; Animals; Bone Density; Bone Development; Cell Differentiation; Chondrogenesis; Face; Hand Deformities, Congenital; Humans; Intellectual Disability; Mice; Micrognathism; Neck; Osteoblasts; Osteoporotic Fractures; SOX9 Transcription Factor; SOXC Transcription Factors; Stem Cells; Wnt Signaling Pathway
PubMed: 26830765
DOI: 10.1007/s11914-016-0296-1 -
European Journal of Human Genetics :... Aug 2023High-throughput sequencing has become a standard first-tier approach for both diagnostics and research-based genetic testing. Consequently, this hypothesis-free... (Review)
Review
High-throughput sequencing has become a standard first-tier approach for both diagnostics and research-based genetic testing. Consequently, this hypothesis-free testing manner has revealed the true breadth of clinical features for many established genetic disorders, including Meier-Gorlin syndrome (MGORS). Previously known as ear-patella short stature syndrome, MGORS is characterized by growth delay, microtia, and patella hypo/aplasia, as well as genital abnormalities, and breast agenesis in females. Following the initial identification of genetic causes in 2011, a total of 13 genes have been identified to date associated with MGORS. In this review, we summarise the genetic and clinical findings of each gene associated with MGORS and highlight molecular insights that have been made through studying patient variants. We note interesting observations arising across this group of genes as the number of patients has increased, such as the unusually high number of synonymous variants affecting splicing in CDC45 and a subgroup of genes that also cause craniosynostosis. We focus on the complicated molecular genetics for DONSON, where we examine potential genotype-phenotype patterns using the first 3D structural model of DONSON. The canonical role of all proteins associated with MGORS are involved in different stages of DNA replication and in addition to summarising how patient variants impact on this process, we discuss the potential contribution of non-canonical roles of these proteins to the pathophysiology of MGORS.
Topics: Female; Humans; Congenital Microtia; Patella; Growth Disorders; Micrognathism
PubMed: 37059840
DOI: 10.1038/s41431-023-01359-z -
Developmental Dynamics : An Official... Aug 2020Mutations in core components of the spliceosome are responsible for a group of syndromes collectively known as spliceosomopathies. Patients exhibit microcephaly,... (Review)
Review
Mutations in core components of the spliceosome are responsible for a group of syndromes collectively known as spliceosomopathies. Patients exhibit microcephaly, micrognathia, malar hypoplasia, external ear anomalies, eye anomalies, psychomotor delay, intellectual disability, limb, and heart defects. Craniofacial malformations in these patients are predominantly found in neural crest cells-derived structures of the face and head. Mutations in eight genes SNRPB, RNU4ATAC, SF3B4, PUF60, EFTUD2, TXNL4, EIF4A3, and CWC27 are associated with craniofacial spliceosomopathies. In this review, we provide a brief description of the normal development of the head and the face and an overview of mutations identified in genes associated with craniofacial spliceosomopathies. We also describe a model to explain how and when these mutations are most likely to impact neural crest cells. We speculate that mutations in a subset of core splicing factors lead to disrupted splicing in neural crest cells because these cells have increased sensitivity to inefficient splicing. Hence, disruption in splicing likely activates a cellular stress response that includes increased skipping of regulatory exons in genes such as MDM2 and MDM4, key regulators of P53. This would result in P53-associated death of neural crest cells and consequently craniofacial malformations associated with spliceosomopathies.
Topics: Animals; Cell Cycle Proteins; Choanal Atresia; Craniofacial Abnormalities; Cyclophilins; DEAD-box RNA Helicases; Deafness; Disease Models, Animal; Eukaryotic Initiation Factor-4A; Exons; Facies; Heart Defects, Congenital; Humans; Intellectual Disability; Mice; Microcephaly; Micrognathism; Mutation; Neural Crest; Neuroepithelial Cells; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-mdm2; Psychomotor Disorders; RNA Splicing Factors; Ribonucleoprotein, U5 Small Nuclear; Spliceosomes; Syndrome; Tumor Suppressor Protein p53
PubMed: 32315467
DOI: 10.1002/dvdy.183 -
American Journal of Respiratory and... Apr 2012Obstructive sleep apnea in infants has a distinctive pathophysiology, natural history, and treatment compared with that of older children and adults. Infants have both... (Comparative Study)
Comparative Study Review
Obstructive sleep apnea in infants has a distinctive pathophysiology, natural history, and treatment compared with that of older children and adults. Infants have both anatomical and physiological predispositions toward airway obstruction and gas exchange abnormalities; including a superiorly placed larynx, increased chest wall compliance, ventilation-perfusion mismatching, and ventilatory control instability. Congenital abnormalities of the airway, such as laryngomalacia, hemangiomas, pyriform aperture stenosis, choanal atresia, and laryngeal webs, may also have adverse effects on airway patency. Additional exacerbating factors predisposing infants toward airway collapse include neck flexion, airway secretions, gastroesophageal reflux, and sleep deprivation. Obstructive sleep apnea in infants has been associated with failure to thrive, behavioral deficits, and sudden infant death. The proper interpretation of infant polysomnography requires an understanding of normative data related to gestation and postconceptual age for apnea, arousal, and oxygenation. Direct visualization of the upper airway is an important diagnostic modality in infants with obstructive apnea. Treatment options for infant obstructive sleep apnea are predicated on the underlying etiology, including supraglottoplasty for severe laryngomalacia, mandibular distraction for micrognathia, tonsillectomy and/or adenoidectomy, choanal atresia repair, and/or treatment of gastroesophageal reflux.
Topics: Adenoids; Adult; Age Factors; Combined Modality Therapy; Craniofacial Abnormalities; Female; Follow-Up Studies; Humans; Hypertrophy; Incidence; Infant; Laryngomalacia; Larynx; Male; Micrognathism; Palatine Tonsil; Polysomnography; Risk Assessment; Severity of Illness Index; Sleep Apnea, Obstructive; Treatment Outcome
PubMed: 22135346
DOI: 10.1164/rccm.201108-1455CI -
Genetics in Medicine : Official Journal... Aug 2022Genome-wide sequencing is increasingly being performed during pregnancy to identify the genetic cause of congenital anomalies. The interpretation of prenatally...
PURPOSE
Genome-wide sequencing is increasingly being performed during pregnancy to identify the genetic cause of congenital anomalies. The interpretation of prenatally identified variants can be challenging and is hampered by our often limited knowledge of prenatal phenotypes. To better delineate the prenatal phenotype of Coffin-Siris syndrome (CSS), we collected clinical data from patients with a prenatal phenotype and a pathogenic variant in one of the CSS-associated genes.
METHODS
Clinical data was collected through an extensive web-based survey.
RESULTS
We included 44 patients with a variant in a CSS-associated gene and a prenatal phenotype; 9 of these patients have been reported before. Prenatal anomalies that were frequently observed in our cohort include hydrocephalus, agenesis of the corpus callosum, hypoplastic left heart syndrome, persistent left vena cava, diaphragmatic hernia, renal agenesis, and intrauterine growth restriction. Anal anomalies were frequently identified after birth in patients with ARID1A variants (6/14, 43%). Interestingly, pathogenic ARID1A variants were much more frequently identified in the current prenatal cohort (16/44, 36%) than in postnatal CSS cohorts (5%-9%).
CONCLUSION
Our data shed new light on the prenatal phenotype of patients with pathogenic variants in CSS genes.
Topics: Abnormalities, Multiple; Chromosomal Proteins, Non-Histone; Face; Genetic Association Studies; Hand Deformities, Congenital; Humans; Intellectual Disability; Micrognathism; Neck; Phenotype
PubMed: 35579625
DOI: 10.1016/j.gim.2022.04.010 -
Genetics in Medicine : Official Journal... Nov 2023Coffin-Siris and Nicolaides-Baraitser syndromes are recognizable neurodevelopmental disorders caused by germline variants in BAF complex subunits. The SMARCC2 BAFopathy...
PURPOSE
Coffin-Siris and Nicolaides-Baraitser syndromes are recognizable neurodevelopmental disorders caused by germline variants in BAF complex subunits. The SMARCC2 BAFopathy was recently reported. Herein, we present clinical and molecular data on a large cohort.
METHODS
Clinical symptoms for 41 novel and 24 previously published affected individuals were analyzed using the Human Phenotype Ontology. For genotype-phenotype correlations, molecular data were standardized and grouped into non-truncating and likely gene-disrupting (LGD) variants. Missense variant protein expression and BAF-subunit interactions were examined using 3D protein modeling, co-immunoprecipitation, and proximity-ligation assays.
RESULTS
Neurodevelopmental delay with intellectual disability, muscular hypotonia, and behavioral disorders were the major manifestations. Clinical hallmarks of BAFopathies were rare. Clinical presentation differed significantly, with LGD variants being predominantly inherited and associated with mildly reduced or normal cognitive development, whereas non-truncating variants were mostly de novo and presented with severe developmental delay. These distinct manifestations and non-truncating variant clustering in functional domains suggest different pathomechanisms. In vitro testing showed decreased protein expression for N-terminal missense variants similar to LGD.
CONCLUSION
This study improved SMARCC2 variant classification and identified discernible SMARCC2-associated phenotypes for LGD and non-truncating variants, which were distinct from other BAFopathies. The pathomechanism of most non-truncating variants has yet to be investigated.
Topics: Humans; Abnormalities, Multiple; Face; Micrognathism; Intellectual Disability; Facies; Neurodevelopmental Disorders; Phenotype; DNA-Binding Proteins; Transcription Factors
PubMed: 37551667
DOI: 10.1016/j.gim.2023.100950