A 7-year-old girl was admitted to the hospital with rapidly progressive vision loss. Since 1 year of age, she had exhibited developmental delay accompanied by visual impairment and neutropenia. Combined with genetic testing and molecular pathogenicity analysis, she was diagnosed with Cohen syndrome (CS) caused by compound heterozygous variants in VPS13B (c.6940+1G>T and c.2911C>T). The c.6940+1G>T variant resulted in exon 38 skipping, leading to a frameshift and premature termination. Reverse transcription quantitative polymerase chain reaction revealed significantly reduced VPS13B gene expression (P<0.05). Bioinformatic analysis suggested that both variants likely produce truncated proteins. This case highlights that integrating clinical features with molecular pathogenicity assessment (DNA, RNA, and protein analysis) can improve early diagnostic accuracy for CS.
Humans ; Female ; Child ; Vesicular Transport Proteins/genetics* ; Developmental Disabilities/etiology* ; Muscle Hypotonia/etiology* ; Myopia/etiology* ; Heterozygote ; Intellectual Disability/etiology* ; Microcephaly/etiology* ; Obesity/genetics* ; Growth Disorders/etiology* ; Retinal Degeneration/genetics* ; Psychomotor Disorders/genetics* ; Fingers/abnormalities*

OBJECTIVE: To explore the clinical phenotype, genotype and genetic characteristics for a patient with unilateral Pigmented paravenous retinochoroidal atrophy (PPRCA) and Retinitis pigmentosa (RP) in the contralateral eye. METHODS: A PPRCA pedigree which had presented at the Department of Medical Genetics of the Eye Hospital of Wenzhou Medical University in August 2021 was selected as the study subject. Clinical data of the family members were collected. The proband underwent wide-field fundus photography, wide-field autofluorescence, full-field electroretinogram (ff-ERG), visual field testing, optical coherence tomography (OCT), and fundus angiography (FFA and ICGA). Blood samples were collected from the proband and family members (parents and two sisters), and buccal mucosal cells were collected from the proband's daughter, and genomic DNA was extracted for each family member. Whole exome sequencing (WES) was performed on the proband. Candidate variants were verified using Sanger sequencing and pathogenicity analysis. This study was approved by the Medical Ethics Committee of the Eye Hospital of Wenzhou Medical University (Ethics No. 2019-134). RESULTS: Wide-angle fundus photography and autofluorescence showed that the right eye was consistent with PPRCA and the left eye with RP. OCT showed that the outer layer of the fovea was intact in the right eye, while disorganized outer segment was found in the fovea of the left eye, and outer segment atrophies outside the fovea were found in both eyes. The amplitudes of ff-ERG decreased significantly in both eyes, and the amplitudes in right eye were slightly higher than those of the left eye. Visual field showed a paracentral arcuate scotoma in the right eye and severe centripetal contraction in the left eye. FFA showed hyperfluorescence in the retinal vein distribution area caused by atrophy of retinal pigment epithelium of the right eye and hypofluorescence related to bone spicule pigmentation, in addition with mottled hypofluorescence of choroid in the left eye. ICGA showed mild paravenous retinochroidal atrophy of the right eye and diffuse choroid capillaries atrophy in the middle and peripheral area of the left eye. WES revealed that the proband had a heterozygous c.2234C>T (p.Thr745Met) variant of the CRB1 gene. Sanger sequencing confirmed that the proband and family members except the father of the proband carried the same CRB1 gene variant. Based on the criteria and guidelines for the classification of genetic variation and related consensus from the American College of Medical Genetics and Genomics (ACMG), this variant was classified as pathogenic (PM3_VeryStrong+PM1+PM2_Supporting +PP3). CONCLUSION The heterozygous c.2234C>T (p.Thr745Met) variant of the CRB1 gene may underlay the unilateral PPRCA with contralateral eye RP in this proband. Above findings have enriched the mutational spectrum of the CRB1 gene.
Humans ; Electroretinography ; Exome Sequencing ; Eye Proteins/genetics* ; Membrane Proteins/genetics* ; Mutation ; Nerve Tissue Proteins/genetics* ; Pedigree ; Phenotype ; Retinitis Pigmentosa/genetics* ; Tomography, Optical Coherence ; Retinal Degeneration ; Eye Diseases, Hereditary

OBJECTIVE: To explore the clinical phenotype and genetic characteristics in two children with Knobloch syndrome (KNO) due to variants of COL18A1 gene. METHODS: Two children presented at the Genetic Eye Disease Clinic of the Eye Hospital of Wenzhou Medical University in October 2023 for ocular lesions were selected as the study subjects. Relevant clinical data and peripheral venous blood samples were collected from the children and their parents. Following genomic DNA extraction, whole-exome sequencing (WES) was carried out. Candidate variants were verified by Sanger sequencing of the family members. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: 2021-212-K-185). RESULTS: Both children exhibited characteristic ocular features of KNO including nystagmus, high myopia, and leopard spot fundus. Additionally, child 1 also presented with congenital occipital bone dysplasia and occipital encephalocele, while child 2 was diagnosed with vitreoretinochoroidopathy and bilateral high myopia. WES has identified compound heterozygous variants of the COL18A1 gene in both children, including a c.3013+3A>C splice-site variant and a c.2743C>T (p.Arg915Ter) nonsense variant in child 1, and a novel c.1702-1G>A splice-site variant and a c.3836C>T (p.Ser1279Leu) missense variant in child 2. A comprehensive literature review has identified 63 domestic and international articles involving 167 patients with KNO whom can be classified into three subtypes, with KNO type I being the most common and caused by pathogenic variants in the COL18A1 gene. Both probands in this study were children with KNO type I. Analysis of the genotype-phenotype correlations and population distribution characteristics revealed that the KNO patients exhibited significant clinical and genetic heterogeneity, along with a broad geographic distribution, with a relatively greater number of cases reported in Brazil and China. and a broad geographic distribution, with the highest numbers reported in Brazil and China. While no significant difference in genotype distribution was observed between Chinese and non-Chinese patients, phenotypic disparities were noted, with the non-Chinese cohort showing significantly higher rates of retinal detachment and developmental delay (P < 0.05), whereas Chinese patients exhibited a greater proportion of macular hypoplasia (P < 0.05). CONCLUSION The main clinical manifestations of KNO include high myopia, vitreoretinal dystrophy, and occipital encephalocele. The novel c.1702-1G>A splice-site variant identified in the COL18A1 gene has expanded the mutational spectrum of KNO type I and provided valuable insights for genetic diagnosis, counseling, and clinical management of the disease.
Humans ; Retinal Detachment/congenital* ; Male ; Female ; Child ; Encephalocele/genetics* ; Exome Sequencing ; Collagen Type XVIII/genetics* ; Phenotype ; Retinal Degeneration/genetics* ; Mutation ; Child, Preschool

OBJECTIVE: To explore the genetic basis for a boy affected with Cohen syndrome. METHODS: A boy admitted to Children's Hospital of Nanjing Medical University in January 2021 was selected as the study subject. Genome DNA was extracted from peripheral blood samples from the child and his parents. Whole exome sequencing (WES) was carried out. And candidate variants were verified by Sanger sequencing. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: 202106060-1). RESULTS: WES revealed that the child has harbored compound heterozygous variants of the VPS13B gene, namely c.1563+1G>A and c.3007insC (p.A1003Afs*13), which were inherited from his mother and father, respectively. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), both variants were rates as pathogenic. The c.3007insC (p.A1003Afs*13) was unreported previously. CONCLUSION The compound heterozygous variants c.1563+1G>A and c.3007insC (p.A1003Afs*13) of the VPS13B gene probably underlay the pathogenesis of Cohen syndrome in this child. Above finding has enriched the mutational spectrum of VPS13B gene.
Humans ; Male ; Vesicular Transport Proteins/genetics* ; Intellectual Disability/genetics* ; Muscle Hypotonia/genetics* ; Microcephaly/genetics* ; Fingers/abnormalities* ; Myopia/genetics* ; Obesity/genetics* ; Developmental Disabilities/genetics* ; Mutation ; Exome Sequencing ; Child ; Heterozygote ; Retinal Degeneration

A boy was admitted at the age of 17 months. He had psychomotor retardation in early infancy. Physical examination revealed microcephalus, unusual facies, and a single palmar crease on his right hand, as well as muscle hypotonia in the extremities and hyperextension of the bilateral shoulder and hip joints. Genetic detection identified two pathogenic compound heterozygous mutations, c.8868-1G>A (splicing) and c.11624_11625del (p.V3875Afs*10), in the VPS13B gene, and thus the boy was diagnosed with Cohen syndrome. Cohen syndrome is a rare autosomal recessive disorder caused by the VPS13B gene mutations and has complex clinical manifestations. Its clinical features include microcephalus, unusual facies, neutropenia, and joint hyperextension. VPS13B gene detection helps to make a confirmed diagnosis.
Base Sequence ; Developmental Disabilities ; diagnosis ; genetics ; Fingers ; abnormalities ; Humans ; Infant ; Intellectual Disability ; diagnosis ; genetics ; Male ; Microcephaly ; diagnosis ; genetics ; Muscle Hypotonia ; diagnosis ; genetics ; Mutation ; Myopia ; diagnosis ; genetics ; Neutropenia ; complications ; genetics ; psychology ; Obesity ; diagnosis ; genetics ; Psychomotor Disorders ; diagnosis ; etiology ; genetics ; Retinal Degeneration ; diagnosis ; genetics ; Vesicular Transport Proteins ; genetics

The role of methyl-CpG binding domain protein 2 (MBD2) in an ApoE-deficient mouse model of age-related macular degeneration (AMD) was investigated. Eight-week-old Mbd2/ApoE double deficient (Mbd2(-/-) ApoE(-/-)) mice (n=12, 24 eyes, experimental group) and MBD2 (wt) ApoE(-/-) mice (n=12, 24 eyes, control group) were fed on Western-type diet for 4 months. The mice were sacrificed, and total serum cholesterol levels were analyzed and Bruch's membrane (BM) of the eyes was removed for ultrastructural observation by transmission electron microscopy. Moreover, intercellular adhesion molecule 1 (ICAM-1) immunoreactivities were evaluated by fluorescence microscopy in sections of the eyes in both groups for further understanding the function mechanism of MBD2. There was no significant difference in the total serum cholesterol levels between control group and experimental group (P>0.05). Transmission electron microscopy revealed that AMD-like lesions, various vacuoles accumulated on BM, notable outer collagenous layer deposits and dilated basal infoldings of retinal pigment epithelium (RPE) were seen in both groups, and the BM in control group was significantly thickened as compared with experimental group (P<0.05). Fluorescence micrographs exhibited the expression of ICAM-1 in choroid was higher in control group than in experimental group. We are led to conclude that MBD2 gene knockout may lead to accumulation of more deposits on the BM and influence the pathogenesis of AMD via triggering endothelial activation and inflammatory response in choroid, improving microcirculation, and reducing lipid deposition so as to inhibit the development of AMD-like lesions. Our study helps to provide a new therapeutic approach for the clinical treatment of AMD.
Animals ; Apolipoproteins E ; genetics ; metabolism ; Bruch Membrane ; metabolism ; ultrastructure ; Cholesterol ; blood ; Choroid ; metabolism ; ultrastructure ; DNA-Binding Proteins ; genetics ; metabolism ; Intercellular Adhesion Molecule-1 ; metabolism ; Macular Degeneration ; blood ; genetics ; metabolism ; Male ; Mice ; Mice, Knockout ; Microscopy, Electron, Transmission ; Microscopy, Fluorescence ; Retinal Pigment Epithelium ; metabolism ; ultrastructure

PURPOSE: To assess whether the expression of heat shock protein 72 (Hsp72) protects rat retinal ganglion cells (RGC-5) from apoptotic cell death. METHODS: Hsp72 expression in RGC-5 cells transduced with replication-deficient recombinant adenovirus was analyzed by Western blot analysis and immunofluorescence. The effect of Hsp72 expression on etoposide-induced apoptotic cell death was examined by microscopic analysis and confirmed by cell proliferation assay. RESULTS: Western blot analysis and immunofluorescence clearly showed adenovirus-mediated Hsp72 expression in RGC-5 cells. Treatment with etoposide resulted in the death of a proportion of the cells by apoptosis. However, this apoptotic cell death was significantly reduced in cells expressing Hsp72, with the reduction in cell death correlating to the level of Hsp72 expression. CONCLUSIONS: Over-expression of Hsp72 alone is sufficient to rescue neuronal cells from apoptotic cell death, suggesting that fine-tuning its expression may be an effective neuroprotective approach in retinal degenerative disease.
Animals ; Blotting, Western ; Cell Death/*genetics ; Cell Survival ; Cells, Cultured ; DNA/*genetics ; Disease Models, Animal ; Etoposide/toxicity ; *Gene Expression Regulation ; HSP72 Heat-Shock Proteins/biosynthesis/*genetics ; Immunohistochemistry ; Rats ; Retinal Degeneration/*genetics/metabolism/pathology ; Retinal Ganglion Cells/drug effects/*metabolism/pathology

Mutations in the Fused in sarcoma/Translated in liposarcoma gene (FUS/TLS, FUS) have been identified among patients with amyotrophic lateral sclerosis (ALS). FUS protein aggregation is a major pathological hallmark of FUS proteinopathy, a group of neurodegenerative diseases characterized by FUS-immunoreactive inclusion bodies. We prepared transgenic Drosophila expressing either the wild type (Wt) or ALS-mutant human FUS protein (hFUS) using the UAS-Gal4 system. When expressing Wt, R524S or P525L mutant FUS in photoreceptors, mushroom bodies (MBs) or motor neurons (MNs), transgenic flies show age-dependent progressive neural damages, including axonal loss in MB neurons, morphological changes and functional impairment in MNs. The transgenic flies expressing the hFUS gene recapitulate key features of FUS proteinopathy, representing the first stable animal model for this group of devastating diseases.
Aged ; Aging ; genetics ; metabolism ; pathology ; Amyotrophic Lateral Sclerosis ; genetics ; metabolism ; pathology ; Animals ; Animals, Genetically Modified ; Disease Models, Animal ; Drosophila melanogaster ; genetics ; metabolism ; Gene Expression ; Humans ; Microscopy, Electron, Scanning ; Motor Neurons ; metabolism ; pathology ; Mushroom Bodies ; metabolism ; pathology ; Mutant Proteins ; genetics ; metabolism ; Mutation ; Photoreceptor Cells, Invertebrate ; metabolism ; pathology ; Plasmids ; RNA-Binding Protein FUS ; genetics ; metabolism ; Recombinant Fusion Proteins ; genetics ; metabolism ; Retinal Degeneration ; pathology ; physiopathology ; Transfection

Exposure to light can induce photoreceptor cell death and exacerbate retinal degeneration. In this study, mice with genetic knockout of several genes, including rhodopsin kinase (Rhok-/-), arrestin (Sag-/-), transducin (Gnat1-/-), c-Fos (c-Fos-/-) and arrestin/transducin (Sag-/-/Gnat1-/-), were examined. We measured the expression levels of thousands of genes in order to investigate their roles in phototransduction signaling in light-induced retinal degeneration using DNA microarray technology and then further explored the gene network using pathway analysis tools. Several cascades of gene components were induced or inhibited as a result of corresponding gene knockout under specific light conditions. Transducin deletion blocked the apoptotic signaling induced by exposure to low light conditions, and it did not require c-Fos/AP-1. Deletion of c-Fos blocked the apoptotic signaling induced by exposure to high intensity light. In the present study, we identified many gene transcripts that are essential for the initiation of light-induced rod degeneration and proposed several important networks that are involved in pro- and anti-apoptotic signaling. We also demonstrated the different cascades of gene components that participate in apoptotic signaling under specific light conditions.
Animals ; Apoptosis/radiation effects ; G-Protein-Coupled Receptor Kinase 1/genetics ; GTP-Binding Protein alpha Subunits/genetics ; *Gene Expression Profiling ; Genes, fos/genetics ; Light/adverse effects ; Light Signal Transduction/*genetics/physiology/radiation effects ; Mice ; Mice, Knockout ; Oligonucleotide Array Sequence Analysis ; Retina/metabolism/pathology/radiation effects ; Retinal Degeneration/etiology/*genetics/physiopathology ; Transducin/genetics

To report a case of Boucher-Neuhauser syndrome, which is an autosomal recessive disorder characterized by the triad of spinocerebellar ataxia, chorioretinal dystrophy, and hypogonadotropic hypogonadism. An 18-year-old man was seen for visual problems, which had been diagnosed as retinitis pigmentosa at the age of 12 years. His puberty was delayed. At 16 years of age, the patient experienced progressive deterioration of his balance and gait disturbance. Then he was referred to our clinic because Boucher-Neuhauser syndrome was suspected. He had no specific family history; his visual acuity was 0.04 in both eyes. We observed broad retinal pigment epithelium atrophy and degeneration in both fundi. Both fluorescein and indocyanine green angiography showed choriocapillaris atrophy in the posterior pole area and midperiphery. Macular optical coherence tomography showed thinning of the neurosensory retina. An electroretinographic examination showed no photopic or scotopic responses. The Boucher-Neuhauser syndrome should be included in the differential diagnosis of patients with retinitis pigment epithelium atrophy and degeneration.
Adolescent ; Atrophy ; Cerebellum/pathology ; Coloring Agents/diagnostic use ; Electroretinography ; Fluorescein Angiography ; Humans ; Hypogonadism/*diagnosis/genetics ; Indocyanine Green/diagnostic use ; Magnetic Resonance Imaging ; Male ; Photoreceptor Cells, Vertebrate/physiology ; Retinal Degeneration/*diagnosis/genetics ; Retinal Pigment Epithelium/*pathology ; Retinitis Pigmentosa/*diagnosis/genetics/physiopathology ; Spinocerebellar Degenerations/*diagnosis/genetics ; Syndrome ; Tomography, Optical Coherence