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Ophthalmic Genetics Jan 2024Variations in have been associated with Brittle Cornea Syndrome that presents with bluish sclera, loss of vision after trivial trauma, arachnodactyly, and joint laxity.
BACKGROUND
Variations in have been associated with Brittle Cornea Syndrome that presents with bluish sclera, loss of vision after trivial trauma, arachnodactyly, and joint laxity.
MATERIALS AND METHODS
Detailed medical and family history, physical examination, and molecular analysis.
RESULTS
A 21-year-old female presented with bluish discoloration of sclera, diminution of vision following trivial trauma in childhood along with hearing loss and systemic features of arachnodactyly and joint laxity. Clinical diagnosis of brittle cornea syndrome was made which was molecularly proven using next-generation sequencing which identified compound heterozygosity in for pathogenic and likely pathogenic nonsense variants. One variant namely NM_001367624.2:c.5882dup was identified in the exon 3 which was novel and classified as likely pathogenic according to American College of Medical Genetics (ACMG) criteria for variant classification. Another variant NM_001367624.2:c.8992C>T in the exon 2 was classified as pathogenic for Brittle Cornea Syndrome 1.
CONCLUSIONS
The report adds to the allelic heterogeneity in causative of Brittle Cornea Syndrome 1 and shall acquaint the physicians about this potentially vision threatening, underdiagnosed, rare syndrome.
PubMed: 38289830
DOI: 10.1080/13816810.2024.2303690 -
Biochemical Genetics Nov 2023Congenital contractural arachnodactyly (CCA) is a rare connective tissue disorder characterized by arachnodactyly, multiple joint contractures, progressive...
Congenital contractural arachnodactyly (CCA) is a rare connective tissue disorder characterized by arachnodactyly, multiple joint contractures, progressive kyphoscoliosis, pectus deformity and abnormal crumpled ears. FBN2 is the only gene currently known to be associated with CCA. In this study, we report on a prenatal case presented with skeletal, cardiac and spinal malformations. And his father had elongated limbs, contractures of the proximal interphalangeal joints, high myopia and scoliosis. We conducted whole exome sequencing (WES) on the fetus-parental trio and a heterozygous variant (hg19 chr5:127,673,685, c.3598 + 4A > G, NM_001999.4) in intron 27 of the FBN2 gene was successfully identified, inherited from the father. Reverse transcriptase-polymerase chain reaction (RT-PCR) was performed to evaluate the potential splicing effect of this variant, which confirmed that the variant caused a deletion of exon 27 (126 bp) by disrupting the splice-donor site and destroyed the 17th calcium-binding epidermal growth factor-like (cbEGF) domain. Our research not only finds the etiology of the disease in affected individuals and expands the mutation spectrum of FBN2 gene, but also provides genetic counseling and fertility guidance for this family.
PubMed: 37962692
DOI: 10.1007/s10528-023-10550-2 -
International Journal of Molecular... May 2024Fibrillin-1 and fibrillin-2, encoded by and , respectively, play significant roles in elastic fiber assembly, with pathogenic variants causing a diverse group of...
Fibrillin-1 and fibrillin-2, encoded by and , respectively, play significant roles in elastic fiber assembly, with pathogenic variants causing a diverse group of connective tissue disorders such as Marfan syndrome (MFS) and congenital contractural arachnodactyly (CCD). Different genomic variations may lead to heterogeneous phenotypic features and functional consequences. Recent high-throughput sequencing modalities have allowed detection of novel variants that may guide the care for patients and inform the genetic counseling for their families. We performed clinical phenotyping for two newborn infants with complex congenital heart defects. For genetic investigations, we employed next-generation sequencing strategies including whole-genome Single-Nucleotide Polymorphism (SNP) microarray for infant A with valvular insufficiency, aortic sinus dilatation, hydronephrosis, and dysmorphic features, and Trio whole-exome sequencing (WES) for infant B with dextro-transposition of the great arteries (D-TGA) and both parents. Infant A is a term male with neonatal marfanoid features, left-sided hydronephrosis, and complex congenital heart defects including tricuspid regurgitation, aortic sinus dilatation, patent foramen ovale, patent ductus arteriosus, mitral regurgitation, tricuspid regurgitation, aortic regurgitation, and pulmonary sinus dilatation. He developed severe persistent pulmonary hypertension and worsening acute hypercapnic hypoxemic respiratory failure, and subsequently expired on day of life (DOL) 10 after compassionate extubation. Cytogenomic whole-genome SNP microarray analysis revealed a deletion within the gene spanning exons 7-30, which overlapped with the exon deletion hotspot region associated with neonatal Marfan syndrome. Infant B is a term male prenatally diagnosed with isolated D-TGA. He required balloon atrial septostomy on DOL 0 and subsequent atrial switch operation, atrial septal defect repair, and patent ductus arteriosus ligation on DOL 5. Trio-WES revealed compound heterozygous c.518C>T and c.8230T>G variants in the gene. Zygosity analysis confirmed each of the variants was inherited from one of the parents who were healthy heterozygous carriers. Since his cardiac repair at birth, he has been growing and developing well without any further hospitalization. Our study highlights novel variants and signifies the phenotype-genotype association in two infants affected with complex congenital heart defects with and without dysmorphic features. These findings speak to the importance of next-generation high-throughput genomics for novel variant detection and the phenotypic variability associated with variants, particularly in the neonatal period, which may significantly impact clinical care and family counseling.
Topics: Humans; Fibrillin-1; Marfan Syndrome; Fibrillin-2; Male; Infant, Newborn; Heart Defects, Congenital; High-Throughput Nucleotide Sequencing; Female; Polymorphism, Single Nucleotide; Mutation; Genomics; Phenotype; Exome Sequencing; Adipokines
PubMed: 38791509
DOI: 10.3390/ijms25105469 -
PLoS Biology Sep 2023Optogenetic actuators have revolutionized the resolution at which biological processes can be controlled. In plants, deployment of optogenetics is challenging due to the...
Optogenetic actuators have revolutionized the resolution at which biological processes can be controlled. In plants, deployment of optogenetics is challenging due to the need for these light-responsive systems to function in the context of horticultural light environments. Furthermore, many available optogenetic actuators are based on plant photoreceptors that might crosstalk with endogenous signaling processes, while others depend on exogenously supplied cofactors. To overcome such challenges, we have developed Highlighter, a synthetic, light-gated gene expression system tailored for in planta function. Highlighter is based on the photoswitchable CcaS-CcaR system from cyanobacteria and is repurposed for plants as a fully genetically encoded system. Analysis of a re-engineered CcaS in Escherichia coli demonstrated green/red photoswitching with phytochromobilin, a chromophore endogenous to plants, but also revealed a blue light response likely derived from a flavin-binding LOV-like domain. We deployed Highlighter in transiently transformed Nicotiana benthamiana for optogenetic control of fluorescent protein expression. Using light to guide differential fluorescent protein expression in nuclei of neighboring cells, we demonstrate unprecedented spatiotemporal control of target gene expression. We implemented the system to demonstrate optogenetic control over plant immunity and pigment production through modulation of the spectral composition of broadband visible (white) light. Highlighter is a step forward for optogenetics in plants and a technology for high-resolution gene induction that will advance fundamental plant biology and provide new opportunities for crop improvement.
Topics: Optogenetics; Nicotiana; Arachnodactyly; Escherichia coli; Gene Expression
PubMed: 37733664
DOI: 10.1371/journal.pbio.3002303 -
Human Genome Variation Feb 2024Congenital contractual arachnodactyly (CCA) is a genetic connective tissue disorder that is characterized by arachnodactyly, kyphoscoliosis, marfanoid habitus, and...
Congenital contractual arachnodactyly (CCA) is a genetic connective tissue disorder that is characterized by arachnodactyly, kyphoscoliosis, marfanoid habitus, and crumpled ears. We report a case of a boy with suspected Marfan syndrome. Genetic analysis revealed c.3207_3217+9del in a heterozygote form of the fibrillin-2 (FBN2) gene. This patient was diagnosed with CCA based on his phenotype, and the pathogenicity of this variant was classified according to cDNA analysis and protein modeling.
PubMed: 38326314
DOI: 10.1038/s41439-024-00264-1 -
Connective Tissue Research May 2024Congenital contractural arachnodactyly (CCA) is an extremely rare autosomal dominant connective tissue genetic disorder caused by pathogenic variants in FBN2. CCA is...
PURPOSE
Congenital contractural arachnodactyly (CCA) is an extremely rare autosomal dominant connective tissue genetic disorder caused by pathogenic variants in FBN2. CCA is characterized by arachnodactyly, camptodactyly, contracture of major joints, scoliosis, pectus deformities, and crumpled ears, but rarely with lethal cardiovascular manifestations as in Marfan syndrome. It is imperative to conduct a comprehensive analysis and review of the pathogenesis of CCA resulting from pathogenic variants in FBN2 gene.
MATERIALS AND METHODS
Using whole-exome sequencing and Sanger sequencing, we identified a novel pathogenic splice-altering variant (c.4472-3C>A) in intron 34 of FBN2 gene in a CCA pedigree. The transcriptional result of the splicing-altering variant was analyzed by RNA sequencing. We systematically analyzed the clinical manifestations of all reported cases of CCA caused by splicing-altering pathogenic variants and focused on all the pathogenic variants in FBN2 gene that are associated with severe cardiovascular manifestations.
RESULTS
The splice-altering variant (c.4472-3C>A) in FBN2 was demonstrated to result in the exon 35 skipping and cause an in-frame deletion. Furthermore, we identified exons 31 to 35 may be a hotspot region in FBN2 gene associated with severe cardiovascular phenotype.
CONCLUSIONS
This study enriched the pathogenic spectrum of CCA and identified a hotspot region in FBN2 gene associated with severe cardiovascular manifestations. We recommend that patients carrying pathogenic variants in exons 31 to 35 of FBN2 pay more attention to cardiac evaluation.
Topics: Fibrillin-2; Humans; Arachnodactyly; Contracture; Male; Female; Pedigree; Mutation
PubMed: 38602424
DOI: 10.1080/03008207.2024.2340004 -
Archives of Oral Biology Feb 2024describing the clinical features of twelve Egyptian patients with Papillon-Lefever syndrome (PLS). Five novel mutations in the cathepsin C (CTSC) gene are introduced and...
OBJECTIVES
describing the clinical features of twelve Egyptian patients with Papillon-Lefever syndrome (PLS). Five novel mutations in the cathepsin C (CTSC) gene are introduced and the phenotype of the syndrome is expanded by the identification of new clinical features.
DESIGN
the clinical, oro-dental data of twelve Egyptian patients from seven unrelated families are described. Sequence analysis of the CTSC gene was performed to identify the causative mutaions.
RESULTS
Typical PLS features were presented in all patints but with variable severity. One patient showed atypical dental features including dental structural defect, minimal periodontitis, severe gingivitis, and delayed closure of root apices. Another patient presented with arachnodactyly, dystrophic nails, and buphthalmos in the right eye secondary to uncontrolled congenital glaucoma. Mutational analysis of CTSC gene revealed seven distinct homozygous variants including five novel ones: c.285_286delGT (p.Leu96GlufsTer2), c .302 G>C (p.Trp101Ser), c.622_628delCACAGTC (p.H208Efs*11), c.1331delinsAAAAA (p.G444Efs*4) and c .1343 G>A (p.Cys448Tyr). The previously reported missense variant c .757 G>A (p.Ala253Thr) was found in one patient. This variant is very close to the splice region and by functional studies, we proved that it results in exon skipping and early protein truncation (p.R214Sfs*46).
CONCLUSION
We report five novel CTSC variants and describe rare and unusual associated clinical and dental findings such as dental structural defects, delayed closure of root apices, and congenital glaucoma. Therefore, our results expand both the phenotypic and mutational spectrum of PLS.
Topics: Humans; Papillon-Lefevre Disease; Cathepsin C; Egypt; Mutation, Missense; Syndrome; Glaucoma
PubMed: 38104461
DOI: 10.1016/j.archoralbio.2023.105869