scholarly journals Novel p.G1344E mutation in FBN1 is associated with ectopia lentis

2020 ◽  
pp. bjophthalmol-2019-315265
Author(s):  
Yuan Yang ◽  
Ya-li Zhou ◽  
Teng-teng Yao ◽  
Hui Pan ◽  
Ping Gu ◽  
...  
Keyword(s):  
Late Onset ◽  
Family Members ◽  
Crystalline Lens ◽  
Pathogenic Mutation ◽  
Ectopia Lentis ◽  
Skeletal Involvement ◽  
Suspensory Ligament ◽  
Pathogenic Variants ◽  
Fibrillin 1 ◽  
Systemic Examination

BackgroundEctopia lentis refers to dislocation or subluxation of the crystalline lens. Fibrillin-1, encoded by FBN1, is an important microfibrillar structural component that is specifically required for the suspensory ligament of the lens. FBN1 mutations may cause abnormal structure of microfibrils and has been associated with a broad spectrum of clinical phenotypes. In this study, we characterised a Chinese dominant family with late-onset isolated ectopia lentis caused by a novel missense FBN1 mutation.MethodsEight family members, including four patients with suspected isolated ectopia lentis, were recruited from Shanghai. Clinical data and family history of the proband and other affected family members were collected. Ophthalmic examination, systemic examination and echocardiography were performed. Whole exome sequencing and Sanger sequencing were used to detect potential pathogenic variants.ResultsA novel heterozygous missense mutation c.4031 G>A/p.Gly1344Glu in exon 33 of FBN1 was identified. This mutation was detected in all affected family members and led to specific ocular system phenotypes (ectopia lentis, microspherophakia and secondary glaucoma) with minor skeletal involvement (hallux valgus).ConclusionThe novel c.4031G>A mutation in FBN1 is a likely pathogenic mutation for isolated ectopia lentis. Our study expands the spectrum of FBN1 mutations and contributes to better comprehension of genotype-phenotype correlations of ectopia lentis disease.

scholarly journals Intricacies of aetiology in intrafamilial degenerative disease

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Jessica L Lowry ◽  
Éanna B Ryan ◽  
Y Taylan Esengul ◽  
Nailah Siddique ◽  
Teepu Siddique
Keyword(s):  
Disease Transmission ◽  
De Novo ◽  
Late Onset ◽  
Family Members ◽  
Degenerative Disease ◽  
De Novo Mutations ◽  
Pathogenic Variants ◽  
Disease Trait ◽  
Disease Aetiology

Abstract The genetic underpinnings of late-onset degenerative disease have typically been determined by screening families for the segregation of genetic variants with the disease trait in affected, but not unaffected, individuals. However, instances of intrafamilial etiological heterogeneity, where pathogenic variants in a culprit gene are not shared among all affected family members, continue to emerge and confound gene-discovery and genetic counselling efforts. Discordant intrafamilial cases lacking a mutation shared by other affected family members are described as disease phenocopies. This description often results in an over-simplified acceptance of an environmental cause of disease in the phenocopy cases, while the role of intrafamilial genetic heterogeneity, shared de novo mutations or epigenetic aberrations in such families is often ignored. On a related note, it is now evident that the same disease-associated variant can be present in individuals exhibiting clinically distinct phenotypes, thereby genetically uniting seemingly unrelated syndromes to form a spectrum of disease. Herein, we discuss the intricacies of determining complex degenerative disease aetiology and suggest alternative mechanisms of disease transmission that may account for the apparent missing heritability of disease.

A novel missense TGFBI variant p.(Ser591Phe) in a Finnish family with variant lattice corneal dystrophy

2021 ◽  
pp. 112067212199730
Author(s):  
Aino Maaria Jaakkola ◽  
Petri J Järventausta ◽  
Reetta-Stiina Järvinen ◽  
Pauliina Repo ◽  
Tero T Kivelä ◽  
...  
Keyword(s):  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Late Onset ◽  
Family Members ◽  
Anterior Segment ◽  
Corneal Dystrophy ◽  
Ophthalmological Examination ◽  
Lattice Corneal Dystrophy ◽  
Tgfbi Gene ◽  
Novel Variant

Introduction: We describe the phenotype of a variant lattice corneal dystrophy (LCD) potentially caused by a novel variant c.1772C>T p.(Ser591Phe) in exon 13 of the transforming growth factor beta-induced (TGFBI) gene. Case report: The proband, a 71-year-old woman referred because of bilateral LCD, first seen at the age of 65 years, with recent progressive symptoms, underwent a clinical ophthalmological examination, anterior segment optical coherence tomography and confocal microscopy. Additionally, three siblings and three children were examined. The identified TGFBI variant was screened in six family members using Sanger sequencing. A corneal dystrophy gene screen was performed for the proband. Translucent subepithelial irregularities and central to midperipheral stubby branching corneal stromal lattice lines, asymmetric between the right and the left eye, were visible and resulted in mild deterioration of vision in one eye. Genetic testing revealed a novel variant c.1772C>T in TGFBI, leading to the amino acid change p.(Ser591Phe). One daughter carried the same variant but had only thick stromal nerve fibres at the age of 49 years. The other family members neither had corneal abnormalities nor carried the variant. No keratoplasty is yet planned for the proband. Conclusions: We classify the novel variant in TGFBI as possibly pathogenic, potentially causing the late-onset, asymmetric variant LCD. Our findings add to the growing number of TGFBI variants associated with a spectrum of phenotypes of variant LCD.

Outcomes of three surgical approaches for managing ectopia lentis in Marfan syndrome

2021 ◽  
pp. 112067212199295
Author(s):  
Gurkan Erdogan ◽  
Nilay Kandemir Besek ◽  
Betul Onal Gunay ◽  
Alper Agca
Keyword(s):  
Marfan Syndrome ◽  
Crystalline Lens ◽  
Surgical Approaches ◽  
Posterior Chamber ◽  
Ectopia Lentis ◽  
Iol Implantation ◽  
Capsular Tension Ring ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

Objective: To investigate the clinical outcomes of three surgical approaches for ectopia lentis in Marfan syndrome (MS) patients who had undergone crystalline lens removal with posterior chamber intraocular lens (IOL) implantation techniques comprising the intrascleral fixation of IOL, sutured scleral fixation of IOL, and IOL implantation with the use of a Cionni capsular tension ring (CTR). Methods: This is a retrospective comparative study, including 35 eyes of 21 patients who underwent the intrascleral fixation of IOL (group 1), scleral IOL fixation with the Z-suture (group 2), and IOL implantation with the use of a Cionni CTR (group 3) following crystalline lens removal. The surgical indications were as follows: no improvement in visual function after eyeglasses or contact lens application due to excessive irregular astigmatism and advanced crystalline lens decentration in which the edge of the crystalline lens came up to the optical axis, or dislocation of the crystalline lens resulting in aphakia and secondary glaucoma due to lens dislocation. The surgical outcomes and complications due to surgery were compared between the groups. Results: The mean age of the patients in the study was 12.3 ± 8.7 years (5–32 years). There were 10 eyes in group 1, 13 eyes in group 2, and 12 eyes in group 3. Visual acuity improved significantly in each group after surgery. Ocular residual astigmatism did not differ significantly between the groups ( p = 0.51). Conclusion: There were no significant differences between the three surgical approaches in the current study in terms of the postoperative results and complications.

Frequency and characterization of mutations in genes in a large cohort of patients referred to MODY registry

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Emily Breidbart ◽  
Liyong Deng ◽  
Patricia Lanzano ◽  
Xiao Fan ◽  
Jiancheng Guo ◽  
...  
Keyword(s):  
Genetic Testing ◽  
Exome Sequencing ◽  
Large Scale ◽  
Age Of Onset ◽  
Family Members ◽  
Ethnically Diverse ◽  
Monogenic Diabetes ◽  
Diabetes Diagnosis ◽  
Pathogenic Variants ◽  
Atypical Diabetes

Abstract Objectives There have been few large-scale studies utilizing exome sequencing for genetically undiagnosed maturity onset diabetes of the young (MODY), a monogenic form of diabetes that is under-recognized. We describe a cohort of 160 individuals with suspected monogenic diabetes who were genetically assessed for mutations in genes known to cause MODY. Methods We used a tiered testing approach focusing initially on GCK and HNF1A and then expanding to exome sequencing for those individuals without identified mutations in GCK or HNF1A. The average age of onset of hyperglycemia or diabetes diagnosis was 19 years (median 14 years) with an average HbA1C of 7.1%. Results Sixty (37.5%) probands had heterozygous likely pathogenic/pathogenic variants in one of the MODY genes, 90% of which were in GCK or HNF1A. Less frequently, mutations were identified in PDX1, HNF4A, HNF1B, and KCNJ11. For those probands with available family members, 100% of the variants segregated with diabetes in the family. Cascade genetic testing in families identified 75 additional family members with a familial MODY mutation. Conclusions Our study is one of the largest and most ethnically diverse studies using exome sequencing to assess MODY genes. Tiered testing is an effective strategy to genetically diagnose atypical diabetes, and familial cascade genetic testing identified on average one additional family member with monogenic diabetes for each mutation identified in a proband.

scholarly journals Fibrillin-1 gene mutations in a Chinese cohort with congenital ectopia lentis: spectrum and genotype–phenotype analysis

2021 ◽  
pp. bjophthalmol-2021-319084
Author(s):  
Zexu Chen ◽  
Tianhui Chen ◽  
Min Zhang ◽  
Jiahui Chen ◽  
Michael Deng ◽  
...  
Keyword(s):  
Calcium Binding ◽  
Gene Mutations ◽  
Mutation Spectrum ◽  
Missense Mutations ◽  
Ectopia Lentis ◽  
Phenotype Analysis ◽  
Chinese Cohort ◽  
Fibrillin 1 ◽  
Epidermal Growth ◽  
Dependent Probe

AimsTo identify the mutation spectrum and genotype–phenotype correlations of fibrillin-1 (FBN1) mutations in a Chinese cohort with congenital ectopia lentis (EL).MethodsPatients clinically suspected of congenital zonulopathy were screened using panel-based next-generation sequencing followed by multiplex ligation-dependent probe amplification. All the probands were subjected to thorough ocular examinations. Molecular and clinical data were integrated in pursuit of genotype–phenotype correlation.ResultsA total of 131 probands of FBN1 mutations from unrelated families were recruited. Around 65% of the probands were children younger than 9 years old. Overall, 110 distinct FBN1 mutations were identified, including 39 novel ones. The most at-risk regions were exons 13, 2, 6, 15, 24 and 33 in descending order of mutation frequency. The most prevalent mutation was c.184C>T (seven, 5.34%) in the coding sequence and c.5788+5G>A (three, 2.29%) in introns. Missense mutations were the most frequent type (103, 78.63%); half of which were distributed in the N-terminal regions (53, 51.46%). The majority of missense mutations were detected in one of the calcium-binding epidermal growth factor-like domains (62, 60.19%), and 39 (62.90%) of them were substitutions of conserved cysteine residues. Microspherophakia (MSP) was found in 15 patients (11.45%). Mutations in the middle region (exons 22–42), especially exon 26, had higher risks of combined MSP (OR, 5.51 (95% CI 1.364 to 22.274), p=0.017).ConclusionsThis study extended the knowledge of the FBN1 mutation spectrum and provided novel insights into its clinical correlation regarding EL and MSP in the Chinese population.

scholarly journals ACTG2-Associated Visceral Myopathy With Chronic Intestinal Pseudoobstruction, Intestinal Malrotation, Hypertrophic Pyloric Stenosis, Choledochal Cyst, and a Novel Missense Mutation

2018 ◽  
Vol 27 (1) ◽  
pp. 77-83 ◽  
Author(s):  
Rebecca R. J. Collins ◽  
Bradley Barth ◽  
Stephen Megison ◽  
Cory M. Pfeifer ◽  
Luke M. Rice ◽  
...  
Keyword(s):  
Choledochal Cyst ◽  
Pyloric Stenosis ◽  
Late Onset ◽  
Smooth Muscle Actin ◽  
Hypertrophic Pyloric Stenosis ◽  
Pathogenic Mutation ◽  
Intestinal Malrotation ◽  
Intestinal Pseudoobstruction ◽  
Chronic Intestinal Pseudoobstruction ◽  
Visceral Myopathy

Primary visceral myopathy caused by a pathogenic mutation in the gene encoding the enteric smooth muscle actin gamma 2 ( ACTG2) affects gastrointestinal and genitourinary tracts and often presents as chronic intestinal pseudoobstruction. We present a case of pediatric onset chronic intestinal pseudoobstruction associated with a novel missense ACTG2 mutation c.439G>T/p.G147C. In addition to the known disease manifestations of feeding intolerance and intestinal malrotation, our patient had a late-onset hypertrophic pyloric stenosis and a late-onset choledochal cyst, the former of which has not previously been described in patients with ACTG2-associated visceral myopathy.

scholarly journals LTBP1 promotes fibrillin incorporation into the extracellular matrix

2021 ◽  
Author(s):  
Matthias Przyklenk ◽  
Veronika Georgieva ◽  
Fabian Metzen ◽  
Sebastian Mostert ◽  
Birgit Kobbe ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Matrix Protein ◽  
Wide Spectrum ◽  
Extracellular Matrix Protein ◽  
Connective Tissues ◽  
Pathogenic Variants ◽  
Human Pathology ◽  
Fibrillin 1

LTBP1 is a large extracellular matrix protein and an associated ligand of fibrillin-microfibrils. Knowledge of LTBP1 functions is largely limited to its role in targeting and sequestering TGFβ growth factors within the extracellular matrix, thereby regulating their bioavailability. However, the recent description of a wide spectrum of phenotypes in multiple tissues in patients harboring LTBP1 pathogenic variants suggests a multifaceted role of the protein in the homeostasis of connective tissues. To better understand the human pathology caused by LTBP1 deficiency it is important to investigate its functional role in extracellular matrix formation. In this study, we show that LTBP1 coordinates the incorporation of fibrillin-1 and -2 into the extracellular matrix in vitro. We also demonstrate that this function is differentially exerted by the two isoforms, the short and long forms of LTBP1. Thereby our findings uncover a novel TGFβ-independent LTBP1 function potentially contributing to the development of connective tissue disorders.

scholarly journals Ataxia teleangiectasia. Az idegrendszeri érintettség prototípusa primer immundefektusokban

2018 ◽  
Vol 159 (49) ◽  
pp. 2057-2064
Author(s):  
Zoltán Liptai
Keyword(s):  
Immune Deficiency ◽  
Ataxia Telangiectasia ◽  
Late Onset ◽  
Brain Mri ◽  
Cerebellar Atrophy ◽  
Biallelic Mutation ◽  
Pathogenic Variants ◽  
Diagnostic Difficulties ◽  
Immune Deficiencies ◽  
Atm Gene

Abstract: The number of primary immune deficiencies exceeds 350, approximately a quarter of them having neurological implications. Severe central nervous system infections may occur in an even higher proportion. Beyond listing in a table of all diseases with a neurological impact, the author gives detailed analysis of one typical disorder. Ataxia telangiectasia is caused by biallelic mutation of the ATM gene resulting in genomic instability, increased cancer risk, immune deficiency and a predominantly cerebellar neurodegeneration. The most common classic form is characterized by gait and limb ataxia, oculomotor apraxia, choreoathetosis, disturbance of speech and swallowing, less often by other movement disorders. There is no remarkable cognitive deficit. Telangiectasia of the conjunctivae and skin usually appears after 6 years of age. Frequent, especially severe sino-pulmonary infections may indicate the immune deficiency present in 60 to 80% of patients, who are also prone to malignancies. The clinical course is sometimes atypical or has a late onset which results in diagnostic difficulties. Serum alpha-fetoprotein level is elevated in nearly all patients. Brain MRI shows progressive cerebellar atrophy starting at the age of 7–8 years. DNA testing of the ATM gene is necessary for the diagnosis. The detected biallelic pathogenic variants provide help for family planning and for possible gene therapies in the future. Ataxia telangiectasia has to be differentiated from a number of other disorders, some of which also belong to primary immune deficiencies. The disorder has no causal treatment at present, the patients live until their young adult ages. Orv Hetil. 2018; 159(49): 2057–2064.

scholarly journals Cardiomyopathy in Genetic Aortic Diseases

2021 ◽  
Vol 9 ◽  
Author(s):  
Laura Muiño-Mosquera ◽  
Julie De Backer
Keyword(s):  
Marfan Syndrome ◽  
Myocardial Dysfunction ◽  
Genetic Defect ◽  
Positive Family History ◽  
Aortic Disease ◽  
Aortic Aneurysms ◽  
Aortic Diseases ◽  
Pathogenic Variants ◽  
Fibrillin 1

Genetic aortic diseases are a group of illnesses characterized by aortic aneurysms or dissection in the presence of an underlying genetic defect. They are part of the broader spectrum of heritable thoracic aortic disease, which also includes those cases of aortic aneurysm or dissection with a positive family history but in whom no genetic cause is identified. Aortic disease in these conditions is a major cause of mortality, justifying clinical and scientific emphasis on the aorta. Aortic valve disease and atrioventricular valve abnormalities are known as important additional manifestations that require careful follow-up and management. The archetype of genetic aortic disease is Marfan syndrome, caused by pathogenic variants in the Fibrillin-1 gene. Given the presence of fibrillin-1 microfibers in the myocardium, myocardial dysfunction and associated arrhythmia are conceivable and have been shown to contribute to morbidity and mortality in patients with Marfan syndrome. In this review, we will discuss data on myocardial disease from human studies as well as insights obtained from the study of mouse models of Marfan syndrome. We will elaborate on the various phenotypic presentations in childhood and in adults and on the topic of arrhythmia. We will also briefly discuss the limited data available on other genetic forms of aortic disease.

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