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Frontiers in Genetics 2022Congenital contractural arachnodactyly (CCA) is a rare autosomal dominant disorder of connective tissue characterized by crumpled ears, arachnodactyly, camptodactyly,...
Congenital contractural arachnodactyly (CCA) is a rare autosomal dominant disorder of connective tissue characterized by crumpled ears, arachnodactyly, camptodactyly, large joint contracture, and kyphoscoliosis. The nature course of CCA has not been well-described. We aim to decipher the genetic and phenotypic spectrum of CCA. The cohort was enrolled in Beijing Jishuitan Hospital and Peking Union Medical College Hospital, Beijing, China, based on Deciphering disorders Involving Scoliosis and COmorbidities (DISCO) study (http://www.discostudy.org/). Exome sequencing was performed on patients' blood DNA. A recent published CCA scoring system was validated in our cohort. Seven novel variants and three previously reported variants were identified through exome sequencing. Two variants outside of the neonatal region of gene were found. The phenotypes were comparable between patients in our cohort and previous literature, with arachnodactyly, camptodactyly and large joints contractures found in almost all patients. All patients eligible for analysis were successfully classified into likely CCA based on the CCA scoring system. Furthermore, we found a double disease-causing heterozygous variant of and in a patient with blended phenotypes consisting of CCA and KBG syndrome. The identification of seven novel variants broadens the mutational and phenotypic spectrum of CCA and may provide implications for genetic counseling and clinical management.
PubMed: 35360850
DOI: 10.3389/fgene.2022.804202 -
Orphanet Journal of Rare Diseases Aug 2019Chromosome 22q11.2 microdeletion syndrome, a disorder caused by heterozygous loss of genetic material in chromosome region 22q11.2, has a broad range of clinical... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Chromosome 22q11.2 microdeletion syndrome, a disorder caused by heterozygous loss of genetic material in chromosome region 22q11.2, has a broad range of clinical symptoms. The most common congenital anomalies involve the palate in 80% of patients, and the heart in 50-60% of them. The cause of the phenotypic variability is unknown. Patients usually harbor one of three common deletions sizes: 3, 2 and 1.5 Mb, between low copy repeats (LCR) designated A-D, A-C and A-B, respectively. This study aimed to analyze the association between these 3 deletion sizes and the presence of congenital cardiac and/or palatal malformations in individuals with this condition. A systematic review and meta-analysis were conducted, merging relevant published studies with data from Chilean patients to increase statistical power.
RESULTS
Eight articles out of 432 were included; the data from these studies was merged with our own, achieving a total of 1514 and 487 patients to evaluate cardiac and palate malformations, respectively. None of the compared deleted chromosomal segments were statistically associated with cardiac defects (OR: 0.654 [0.408-1.046]; OR : 1.291 [0.860-1.939]) or palate anomalies (OR: 1.731 [0.708-4.234]; OR : 0.628 [0.286-1.382]).
CONCLUSIONS
The lack of association between deletion size and CHD or PA found in this meta-analysis suggests that deletion size does not explain the incomplete penetrance of these 2 major manifestations, and that the critical region for the development of heart and palatal abnormalities is within LCR A-B, the smallest region of overlap among the three deletion sizes.
Topics: Arachnodactyly; Chromosome Deletion; Craniosynostoses; Humans; Marfan Syndrome; Phenotype
PubMed: 31399107
DOI: 10.1186/s13023-019-1170-x -
American Journal of Medical Genetics.... Dec 2021Heritable connective tissue disorders are a group of diseases, each rare, characterized by various combinations of skin, joint, musculoskeletal, organ, and vascular...
Heritable connective tissue disorders are a group of diseases, each rare, characterized by various combinations of skin, joint, musculoskeletal, organ, and vascular involvement. Although kidney abnormalities have been reported in some connective tissue disorders, they are rarely a presenting feature. Here we present three patients with prominent kidney phenotypes who were found by whole exome sequencing to have variants in established connective tissue genes associated with Loeys-Dietz syndrome and congenital contractural arachnodactyly. These cases highlight the importance of considering connective tissue disease in children presenting with structural kidney disease and also serves to expand the phenotype of Loeys-Dietz syndrome and possibly congenital contractural arachnodactyly to include cystic kidney disease and cystic kidney dysplasia, respectively.
Topics: Adolescent; Arachnodactyly; Child; Connective Tissue; Connective Tissue Diseases; Contracture; Fibrillin-2; Genetic Predisposition to Disease; Humans; Kidney; Kidney Diseases, Cystic; Loeys-Dietz Syndrome; Male; Mutation; Phenotype; Receptor, Transforming Growth Factor-beta Type I; Skin Abnormalities; Smad2 Protein; Exome Sequencing
PubMed: 34355836
DOI: 10.1002/ajmg.a.62449 -
JMIR Pediatrics and Parenting Oct 2020Young people with genetic conditions often face challenges coping with their health condition. It can be difficult for them to meet someone with a similar condition,...
BACKGROUND
Young people with genetic conditions often face challenges coping with their health condition. It can be difficult for them to meet someone with a similar condition, which is important for reinforcement of chronic illness management recommendations. Social media is used by 97% of young people in the United States and may provide those with these disorders a space for emotional expression and support. However, there is a scarcity of literature related to the use of social media among adolescents with genetic conditions as an indicator of their perception regarding their own condition.
OBJECTIVE
The purpose of this pilot study was to obtain preliminary data to assess and understand social media use by young people with connective tissue disorders and determine whether they use social media to connect with patients with similar conditions or whether they would be interested in doing so.
METHODS
We undertook a pilot study of selected connective tissue disorders occurring in young people between the ages of 11 and 25 years, including Marfan syndrome; Ehlers-Danlos syndrome subtypes classical, classical-like, cardiac-valvular, and vascular; Beals congenital contractual arachnodactyly; and Alport hereditary nephritis. The study took place within one pediatric clinical system. Patients were identified through electronic medical record search and International Classification of Diseases, Ninth Revision, coding at a Midwest university-based clinical system. Study subjects completed a short survey describing their experiences with their connective tissue disorders, their means of self-expression, their existing network of persons to communicate with, and their use of social media. Data analysis included nominal and bivariate regressions to compare social media use in relation to age.
RESULTS
Our 31 participants (42% response rate) were 55% female (17/31) and their average age was 18 years (SD 5). All participants used social media and there were no statistically significant differences between social media use and age. The majority of participants (25/30, 83%) reported that they never used social media to discuss their condition (P=.09), and only 17% (5/30) knew someone online with a similar condition (P=.50). Most participants (19/30, 63%) said they would communicate with someone with a similar disorder (P=.64).
CONCLUSIONS
We found that young individuals with connective tissue disorders use at least one type of social media. A majority did not use social media to discuss their condition or know someone online with a similar condition. However, many persons were interested in finding others similarly affected. Social media could serve as a platform for young people with connective tissue disorders to connect. Peer support is important in disease management and adolescent development. Future studies should aim at understanding social media use among young people with connective tissue disorders and helping them connect with other people who have similar conditions.
PubMed: 33124992
DOI: 10.2196/16367 -
Journal of Medical Genetics Oct 2022Elevated transforming growth factor-beta (TGF-β) signalling has been implicated in the pathogenesis of Loeys-Dietz syndrome (LDS) and Shprintzen-Goldberg syndrome...
BACKGROUND
Elevated transforming growth factor-beta (TGF-β) signalling has been implicated in the pathogenesis of Loeys-Dietz syndrome (LDS) and Shprintzen-Goldberg syndrome (SGS). In this study, we provide a qualitative and quantitative analysis of the craniofacial and functional features among the LDS subtypes and SGS.
METHODS
We explore the variability within and across a cohort of 44 patients through deep clinical phenotyping, three-dimensional (3D) facial photo surface analysis, cephalometric and geometric morphometric analyses of cone-beam CT scans.
RESULTS
The most common craniofacial features detected in this cohort include mandibular retrognathism (84%), flat midface projection (84%), abnormal eye shape (73%), low-set ears (73%), abnormal nose (66%) and lip shape (64%), hypertelorism (41%) and a relatively high prevalence of nystagmus/strabismus (43%), temporomandibular joint disorders (38%) and obstructive sleep apnoea (23%). 3D cephalometric analysis demonstrated an increased cranial base angle with shortened anterior cranial base and underdevelopment of the maxilla and mandible, with evidence of a reduced pharyngeal airway in 55% of those analysed. Geometric morphometric analysis confirmed that the greatest craniofacial shape variation was among patients with LDS type 2, with distinct clustering of patients with SGS.
CONCLUSIONS
This comprehensive phenotypic approach identifies developmental abnormalities that segregate to mutation variants along the TGF-β signalling pathway, with a particularly severe phenotype associated with and mutations. Multimodality assessment of craniofacial anomalies objectively reveals the impact of mutations of the TGF-β pathway with perturbations associated with the cranium and cranial base with severe downstream effects on the orbit, maxilla and mandible with the resultant clinical phenotypes.
Topics: Arachnodactyly; Craniosynostoses; Humans; Loeys-Dietz Syndrome; Marfan Syndrome; Receptor, Transforming Growth Factor-beta Type II; Transforming Growth Factor beta; Transforming Growth Factors
PubMed: 34916229
DOI: 10.1136/jmedgenet-2021-107695 -
The American Journal of Psychiatry Jul 2020
Topics: Arachnodactyly; DiGeorge Syndrome; Genetic Variation; Humans; Marfan Syndrome; Psychotic Disorders
PubMed: 32605438
DOI: 10.1176/appi.ajp.2020.20050598 -
Italian Journal of Pediatrics Jun 2022Loeys-Dietz syndrome (LDS) is a rare connective tissue disorder characterized by cardiovascular manifestations, especially aortic dilatations and arterial tortuosity,... (Review)
Review
BACKGROUND
Loeys-Dietz syndrome (LDS) is a rare connective tissue disorder characterized by cardiovascular manifestations, especially aortic dilatations and arterial tortuosity, craniofacial and skeletal features, joint laxity or contractures, skin abnormalities, hypotonia and motor delay. Its diagnosis is established by the identification of a pathogenic variant in TGFBR1, TGFBR2, SMAD2, SMAD3, TGFB2 or TGFB3 genes. In newborns and toddlers, vascular complications such as aneurism rupture, aortic dissection, and intracerebral incidents, can occur already in the weeks of life. To avoid these events, it is crucial to precociously identify this condition and to start an apunderwent a surgical procedurepropriate treatment which, depending on the severity of the vascular involvement, might be medical or surgical.
CASE PRESENTATION
We report two cases of Loeys-Dietz syndrome precociously diagnosed. The first describes a male, born at 38 + 1 weeks of gestation, with hypotonia, joint hypermobility, arachnodactyly, and fingers joint contractures, as well as senile appearance and facial dysmorphisms. In the suspect of a connective tissue disorder, an echocardiography was performed and revealed an aortic root dilatation of 13 mm (Z score + 3). A trio based Whole Exome Sequencing found a novel de novo variant in the TGFBR2 gene. Despite the onset of a low-dose angiotensin receptor blocker therapy, the aneurysm progressed. The second case describes a female, born at 41 + 3 weeks of gestation. During the neonatal examination a cleft palate was noticed, as well as minor dysmorphisms. Since the family history was suspicious for connective tissue disorders, a genetic panel was performed and identified a pathogenetic variant in TGFB3 gene. In this case, the echocardiography revealed no abnormalities.
CONCLUSIONS
In addition to our cases, we identified 14 subjects with neonatal LDS in the medical literature. All of them had aortic involvement. Skeletal and face abnormalities, including eyes and palate malformations, were also highly frequent. Overall, 10 subjects required medical therapy to avoid aneurysm progression, and 8 patients underwent surgical procedures. Benefits of an early diagnosis of LDS are various and imply a potential modification of the natural history of the disease with early interventions on its complications.
Topics: Connective Tissue Diseases; Contracture; Female; Humans; Infant, Newborn; Loeys-Dietz Syndrome; Male; Muscle Hypotonia; Receptor, Transforming Growth Factor-beta Type II; Transforming Growth Factor beta3
PubMed: 35668506
DOI: 10.1186/s13052-022-01281-y -
Cold Spring Harbor Molecular Case... Oct 2022Neonatal Marfan syndrome (nMFS) is a rare and severe form of Marfan syndrome (MFS) with a poor prognosis, that presents with a highly variable phenotype, particularly...
Neonatal Marfan syndrome (nMFS) is a rare and severe form of Marfan syndrome (MFS) with a poor prognosis, that presents with a highly variable phenotype, particularly regarding skeletal, ocular, and cardiovascular manifestations. Mutations in the fibrillin-1 () gene are known as the principal cause of MFS and MFS-related syndromes. Here, we report on a full-term female neonate with postnatal characteristics suggestive of nMFS, including severe cardiovascular disease resulting in cardiorespiratory failure and death by 4 mo of age. We identified a novel large genomic in-frame deletion of exons 42-45, c.(5065 + 1_5066 - 1)_(5545 + 1_5546 - 1)del. Large in-frame deletions between exons 24 and 53 have been associated with severe MFS. The deletion in our patient differs from the region associated with the majority of nMFS cases, exons 24-32.
Topics: Female; Humans; Exons; Fibrillin-1; Marfan Syndrome; Mutation; Phenotype; Sequence Deletion
PubMed: 36307213
DOI: 10.1101/mcs.a006213 -
BMC Bioinformatics Sep 2022In Alzheimer's Diseases (AD) research, multimodal imaging analysis can unveil complementary information from multiple imaging modalities and further our understanding of...
BACKGROUND
In Alzheimer's Diseases (AD) research, multimodal imaging analysis can unveil complementary information from multiple imaging modalities and further our understanding of the disease. One application is to discover disease subtypes using unsupervised clustering. However, existing clustering methods are often applied to input features directly, and could suffer from the curse of dimensionality with high-dimensional multimodal data. The purpose of our study is to identify multimodal imaging-driven subtypes in Mild Cognitive Impairment (MCI) participants using a multiview learning framework based on Deep Generalized Canonical Correlation Analysis (DGCCA), to learn shared latent representation with low dimensions from 3 neuroimaging modalities.
RESULTS
DGCCA applies non-linear transformation to input views using neural networks and is able to learn correlated embeddings with low dimensions that capture more variance than its linear counterpart, generalized CCA (GCCA). We designed experiments to compare DGCCA embeddings with single modality features and GCCA embeddings by generating 2 subtypes from each feature set using unsupervised clustering. In our validation studies, we found that amyloid PET imaging has the most discriminative features compared with structural MRI and FDG PET which DGCCA learns from but not GCCA. DGCCA subtypes show differential measures in 5 cognitive assessments, 6 brain volume measures, and conversion to AD patterns. In addition, DGCCA MCI subtypes confirmed AD genetic markers with strong signals that existing late MCI group did not identify.
CONCLUSION
Overall, DGCCA is able to learn effective low dimensional embeddings from multimodal data by learning non-linear projections. MCI subtypes generated from DGCCA embeddings are different from existing early and late MCI groups and show most similarity with those identified by amyloid PET features. In our validation studies, DGCCA subtypes show distinct patterns in cognitive measures, brain volumes, and are able to identify AD genetic markers. These findings indicate the promise of the imaging-driven subtypes and their power in revealing disease structures beyond early and late stage MCI.
Topics: Alzheimer Disease; Arachnodactyly; Brain; Cognitive Dysfunction; Contracture; Fluorodeoxyglucose F18; Genetic Markers; Humans; Magnetic Resonance Imaging; Positron-Emission Tomography
PubMed: 36175853
DOI: 10.1186/s12859-022-04946-x -
Scientific Reports Mar 2022MASS phenotype is a connective tissue disorder clinically overlapping with Marfan syndrome and caused by pathogenic variants in FBN1. We report four patients from three...
MASS phenotype is a connective tissue disorder clinically overlapping with Marfan syndrome and caused by pathogenic variants in FBN1. We report four patients from three families presenting with a MASS-like phenotype consisting of tall stature, arachnodactyly, spinal deformations, dural ectasia, pectus and/or feet deformations, osteoarthritis, and/or high arched palate. Gene panel sequencing was negative for FBN1 variants. However, it revealed likely pathogenic missense variants in three individuals [c.3936G > T p.(Lys1312Asn), c.193G > A p.(Asp65Asn)] and a missense variant of unknown significance in the fourth patient [c.4013G > A p.(Ser1338Asn)] in propeptide coding regions of COL2A1. Pathogenic COL2A1 variants are associated with type II collagenopathies comprising a remarkable clinical variablility. Main features include skeletal dysplasia, ocular anomalies, and auditory defects. A MASS-like phenotype has not been associated with COL2A1 variants before. Thus, the identification of likely pathogenic COL2A1 variants in our patients expands the phenotypic spectrum of type II collagenopathies and suggests that a MASS-like phenotype can be assigned to various hereditary disorders of connective tissue. We compare the phenotypes of our patients with related disorders of connective tissue and discuss possible pathomechanisms and genotype-phenotype correlations for the identified COL2A1 variants. Our data recommend COL2A1 sequencing in FBN1-negative patients suggestive for MASS/Marfan-like phenotype (without aortopathy).
Topics: Collagen Type II; Genotype; Humans; Marfan Syndrome; Mitral Valve Prolapse; Mutation; Myopia; Phenotype; Skin Diseases
PubMed: 35296718
DOI: 10.1038/s41598-022-08476-7