scholarly journals Disruption of PIKFYVE causes congenital cataract in human and zebrafish

eLife ◽  
2022 ◽  
Vol 11 ◽  
Author(s):  
Shaoyi Mei ◽  
Yi Wu ◽  
Yan Wang ◽  
Yubo Cui ◽  
Miao Zhang ◽  
...  
Keyword(s):  
Congenital Cataract ◽  
Molecular Mechanisms ◽  
Kinase Domain ◽  
Dominant Negative ◽  
Chinese Family ◽  
Bafilomycin A1 ◽  
Atpase Inhibitor ◽  
Causative Gene ◽  
Whole Exome ◽  
Pathological Variant

Congenital cataract, an ocular disease predominantly occurring within the first decade of life, is one of the leading causes of blindness in children. However, the molecular mechanisms underlying the pathogenesis of congenital cataract remain incompletely defined. Through whole-exome sequencing of a Chinese family with congenital cataract, we identified a potential pathological variant (p.G1943E) in PIKFYVE, which is located in the PIP kinase domain of the PIKFYVE protein. We demonstrated that heterozygous/homozygous disruption of PIKFYVE kinase domain, instead of overexpression of PIKFYVEG1943E in zebrafish mimicked the cataract defect in human patients, suggesting that haploinsufficiency, rather than dominant-negative inhibition of PIKFYVE activity caused the disease. Phenotypical analysis of pikfyve zebrafish mutants revealed that loss of Pikfyve caused aberrant vacuolation (accumulation of Rab7+Lc3+ amphisomes) in lens cells, which was significantly alleviated by treatment with the V-ATPase inhibitor bafilomycin A1 (Baf-A1). Collectively, we identified PIKFYVE as a novel causative gene for congenital cataract and pinpointed the potential application of Baf-A1 for the treatment of congenital cataract caused by PIKFYVE deficiency.

scholarly journals Mutations in PIKFYVE cause autosomal dominant congenital cataract

2021 ◽  
Author(s):  
Shaoyi Mei ◽  
Yi Wu ◽  
Yan Wang ◽  
Yubo Cui ◽  
Miao Zhang ◽  
...  
Keyword(s):  
Congenital Cataract ◽  
Autosomal Dominant ◽  
Kinase Domain ◽  
Dominant Negative ◽  
Chinese Family ◽  
Bafilomycin A1 ◽  
Atpase Inhibitor ◽  
Causative Gene ◽  
Whole Exome ◽  
Autosomal Dominant Congenital Cataract

Congenital cataract, an ocular disease predominantly occurring within the first decade of life, is one of the leading causes of blindness in children. Through whole exome sequencing of a Chinese family with congenital cataract, we identified a disease-causing mutation (p.G1943E) in PIKFYVE, which affecting the PIP kinase domain of the PIKfyve protein. We demonstrated that heterozygous/homozygous disruption of PIKfyve kinase domain, instead of overexpression of PIKFYVEG1943E in zebrafish mimicked the cataract defect in human patients, suggesting that haploinsufficiency, rather than dominant-negative inhibition of PIKfyve activity caused the disease. Phenotypical analysis of pikfyve zebrafish mutants revealed that loss of Pikfyve caused aberrant vacuolation (accumulation of Rab7+Lc3+ amphisomes) in lens cells, which was significantly alleviated by treatment with the V-ATPase inhibitor bafilomycin A1 (Baf-A1). Collectively, we identified PIKFYVE as a novel causative gene for congenital cataract and demonstrated the potential application of Baf-A1 in treatment of congenital cataract.

scholarly journals A Novel CRYBB2 Stopgain Mutation Causing Congenital Autosomal Dominant Cataract in a Chinese Family

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Yu Zhou ◽  
Yaru Zhai ◽  
Lulin Huang ◽  
Bo Gong ◽  
Jie Li ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Congenital Cataract ◽  
Autosomal Dominant ◽  
Family Members ◽  
Chinese Family ◽  
Heterozygous Mutation ◽  
Whole Exome ◽  
Causal Mutation ◽  
Control Samples

Congenital cataract is the most common cause of the visual disability and blindness in childhood. This study aimed to identify gene mutations responsible for autosomal dominant congenital cataract (ADCC) in a Chinese family using next-generation sequencing technology. This family included eight unaffected and five affected individuals. After complete ophthalmic examinations, the blood samples of the proband and two available family members were collected. Then the whole exome sequencing was performed on the proband and Sanger sequencing was applied to validate the causal mutation in the two family members and control samples. After the whole exome sequencing data were filtered through a series of existing variation databases, a heterozygous mutation c.499T<G (p.E167X) in CRYBB2 gene was found. And the results showed that the mutation cosegregated with the disease phenotype in the family and was absolutely absent in 1000 ethnicity-matched control samples. Thus, the heterozygous mutation c.499T<G (p.E167X) in CRYBB2 was the causal mutation responsible for this ADCC family. In conclusion, our findings revealed a novel stopgain mutation c.499T<G (p.E167X) in the exon 6 of CRYBB2 which expanded the mutation spectrum of CRYBB2 in Chinese congenital cataract population and illustrated the important role of CRYBB2 in the genetics research of congenital cataract.

scholarly journals Biallelic Mutations in WDR12 is Associated With Male Infertility With Tapered-Head Sperm

2021 ◽  
Author(s):  
juan hua ◽  
Lan Guo ◽  
Yao Yao ◽  
Yangyang Wan ◽  
Wen Hu ◽  
...  
Keyword(s):  
Male Infertility ◽  
Molecular Mechanisms ◽  
Missense Variant ◽  
Bioinformatic Analysis ◽  
Chinese Family ◽  
Intense Staining ◽  
Whole Exome ◽  
Repeat Domain ◽  
Biallelic Mutations ◽  
Pachytene Spermatocytes

Abstract Teratozoospermia is a rare disease associated with male infertility. Unfortunately, approximately 30% of the genetic causes associated with teratozoospermia remain unknown. Several recurrent genetic mutations have been reported to be associated with globozoospermia, macrozoospermia and acephalic spermatozoa, whereas the genetic basis of tapered-head sperm is relatively less well-understood. In this study, whole-exome sequencing (WES) identified a homozygous WD repeat domain 12 (WDR12) (p.Ser162Ala/c.484T>G) variant in an infertile patient with tapered-head sperm from a consanguineous Chinese family. Bioinformatic analysis predicted this mutation to be a pathogenic variant. To further verify the effect of this variant, we analyzed WDR12 protein expression in the patient’s spermatozoa by western blot and found WDR12 to be significantly down-regulated. Also, we found that WDR12 expression is increased in pachytene spermatocytes, and intense staining was visible throughout the round spermatids in mouse testis. Based on our results, we concluded that a rare biallelic pathogenic missense variant (p.Ser162Ala/c.484T>G) in the WDR12 gene causes teratozoospermia. These results will provide novel insights into understanding the molecular mechanisms of male infertility and will help clinicians provide accurate diagnoses.

scholarly journals Functional Characterization of a Missense Variant of MLH1 Identified in Lynch Syndrome Pedigree

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Tahir Zaib ◽  
Chunhui Zhang ◽  
Komal Saleem ◽  
Lidan Xu ◽  
Qian Qin ◽  
...  
Keyword(s):  
Lynch Syndrome ◽  
Functional Characterization ◽  
Family Members ◽  
Missense Variant ◽  
Chinese Family ◽  
Causative Gene ◽  
Bioinformatic Tools ◽  
Whole Exome

Lynch syndrome (LS) is the most common hereditary colorectal cancer (CRCs) inherited in an autosomal-dominant manner. Here, we reported a multigeneration Chinese family clinically diagnosed with LS according to the Amsterdam II criteria. To identify the underlying causative gene for LS in this family, whole-exome sequencing (WES) was performed. A germline missense variant (c.2054C>T:p.S685F) in exon 18 of MLH1 was successfully identified by WES. Sanger sequencing verified the results of WES and also confirmed the cosegregation of the MLH1 missense variant in all affected members of the family including two unaffected family members. Bioinformatic tools predicted the identified MLH1 variant as deleterious. Immunohistochemistry (IHC) staining showed loss of MLH1 and PMS2 protein expression. In vitro expression analysis also revealed that the identified MLH1 missense variant (c.2054C>T:p.S685F) results in reduced expression of both MLH1 and PMS2 proteins. Based on the American College of Medical Genetics and Genomics (ACMG) guidelines, the missense mutation c.2054C>T in MLH1 was classified as a “pathogenic” variant. Two unaffected family members were later recommended for colonoscopy and other important cancer diagnostic inspections every 1-2 years as both were at higher risk of LS. In conclusion, our findings widen the genotypic spectrum of MLH1 mutations responsible for LS. This study increases the phenotypic spectrum of LS which will certainly help the clinicians in diagnosing LS in multigeneration families. This study also puts emphasis on the importance of genetic counselling for the benefit of asymptomatic carriers of MMR gene variants who are at higher risk of LS.

scholarly journals FKBPL and FKBP8 regulate DLK degradation and neuronal responses to axon injury

2021 ◽  
Author(s):  
Bohm Lee ◽  
Yeonsoo Oh ◽  
Eunhye Cho ◽  
Aaron DiAntonio ◽  
Valeria Cavalli ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Axon Regeneration ◽  
Kinase Domain ◽  
Interacting Proteins ◽  
Bafilomycin A1 ◽  
Neuronal Responses ◽  
Yeast Two Hybrid ◽  
Two Hybrid ◽  
Hybrid Screening

DLK is a key regulator of axon regeneration and degeneration in response to neuronal injury. To understand the molecular mechanisms controlling the DLK function, we performed yeast two-hybrid screening analysis and identified FKBPL as a DLK-binding protein that bound to the kinase domain and inhibited the kinase enzymatic activity of DLK. FKBPL regulated DLK stability through ubiquitin-dependent DLK degradation. We tested other members in the FKBP protein family and found that FKBP8 also induced DLK degradation as FKBPL did. We found that Lysine 271 residue in the kinase domain of DLK was a major site of ubiquitination and SUMO3-conjugation and responsible for FKBP8-mediated degradation. In vivo overexpression of FKBP8 delayed progression of axon degeneration and neuronal death following axotomy in sciatic and optic nerves, respectively, although axon regeneration efficiency was not enhanced. This research identified FKBPL and FKBP8 as new DLK-interacting proteins that regulated DLK stability by MG-132 or bafilomycin A1-sensitive protein degradation.

scholarly journals Novel SOX2 Mutation in Autosomal Dominant Cataract-Microcornea Syndrome

2021 ◽  
Author(s):  
Zhi-Bo Lin ◽  
Jin Li ◽  
Hai-Sen Sun ◽  
A-Yong Yu ◽  
Shi-Hao Chen ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Missense Mutation ◽  
Whole Exome Sequencing ◽  
Sanger Sequencing ◽  
Congenital Cataract ◽  
Autosomal Dominant ◽  
Family Members ◽  
High Mobility ◽  
Chinese Family ◽  
Whole Exome

Abstract Background: Congenital cataract-microcornea syndrome (CCMC) is characterized by the association of congenital cataract and microcornea without any other systemic anomaly or dysmorphism. Although several causative genes have been reported in patients with CCMC, the genetic etiology of CCMC is yet to be clearly understood. Purpose: To unravel the genetic cause of autosomal dominant family with CCMC.Methods: All patients and available family members underwent a comprehensive ophthalmologic clinical examination in the hospital by expert ophthalmologists and carried out to clinically diagnosis. All the patients were screened by whole-exome sequencing and then validated using co-segregation by Sanger sequencing. Results: Four CCMC patients from a Chinese family, and five unaffected family members were enrolled in this study. Using whole-exome sequencing, missense mutation c.295G>T (p.a99s, NM_003106.4) in the SOX2 gene was identified and validated by segregation analysis. In addition, this missense mutation was predicted to be damaging by multiple predictive tools. Variant p.Ala99Ser was located in a conservation high mobility group (HMG)-box domain in SOX2 protein, with a potential pathogenic impact of p.Ala99Ser on protein level.Conclusions: A novel missense mutation (c.295G>T, p.Ala99Ser) in the SOX2 gene was found in this Han Chinese family with congenital cataract and microcornea. Our study firstly determined that mutations in SOX2 were associated with CCMC, warranting further investigations on the pathogenesis of this disorder. This result expands the mutation spectrum of SOX2 and provides useful information to study the molecular pathogenesis of CCMC.

scholarly journals Case Report: A Novel Missense Variant in the SIPA1L3 Gene Associated With Cataracts in a Chinese Family

2021 ◽  
Vol 12 ◽  
Author(s):  
Duo Yang ◽  
Haiyan Zhou ◽  
Jiwu Lin ◽  
Shuangxi Zhao ◽  
Hao Zhou ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Age Of Onset ◽  
Missense Variant ◽  
Mutation Spectrum ◽  
Regulatory Function ◽  
Chinese Family ◽  
Gtpase Activating Protein ◽  
Juvenile Onset ◽  
Whole Exome ◽  
Functional Alteration

The signal-induced proliferation-associated 1-like 3 (SIPA1L3) gene that encodes a putative Rap GTPase-activating protein (RapGAP) has been associated with congenital cataract and eye development abnormalities. However, our current understanding of the mutation spectrum of SIPA1L3 associated with eye defects is limited. By using whole-exome sequencing plus Sanger sequencing validation, we identified a novel heterozygous c.1871A &gt; G (p.Lys624Arg) variation within the predicted RapGAP domain of SIPA1L3 in the proband with isolated juvenile-onset cataracts from a three-generation Chinese family. In this family, the proband's father and grandmother were also heterozygous for the c.1871A &gt; G variation and affected by cataracts varying in morphology, severity, and age of onset. Sequence alignment shows that the Lys 624 residue of SIPA1L3 is conserved across the species. Based on the resolved structure of Rap1–Rap1GAP complex, homology modeling implies that the Lys 624 residue is structurally homologous to the Lys 194 of Rap1GAP, a highly conserved lysine residue that is involved in the interface between Rap1 and Rap1GAP and critical for the affinity to Rap·GTP. We reasoned that arginine substitution of lysine 624 might have an impact on the SIPA1L3-Rap·GTP interaction, thereby affecting the regulatory function of SIPA1L3 on Rap signaling. Collectively, our finding expands the mutation spectrum of SIPA1L3 and provides new clues to the molecular mechanisms of SIPA1L3-related cataracts. Further investigations are warranted to validate the functional alteration of the p.Lys624Arg variant of SIPA1L3.

A novel missense mutation of CRYBA1 in a northern Chinese family with inherited coronary cataract with blue punctate opacities

2021 ◽  
pp. 112067212110083
Author(s):  
Shu-Hua Ni ◽  
Juan-Mei Zhang ◽  
Jun Zhao
Keyword(s):  
Missense Mutation ◽  
High Throughput Sequencing ◽  
Bioinformatics Analysis ◽  
Genetic Defect ◽  
Kinase Domain ◽  
Chinese Family ◽  
Heterozygous Mutation ◽  
Scale Invariant ◽  
The Family ◽  
Northern Chinese

Purpose: To demonstrate the underlying genetic defect that contribute to inherited cataract in a northern Chinese pedigree. Methods: The study recruited a family pedigree with a diagnosis of bilateral coronary cataract with blue punctate opacities. Fourteen family members and 100 healthy volunteers were enrolled. DNA sample of the proband in this family were analyzed by high-throughput sequencing, which was then demonstrated by Sanger sequencing in the remained people in the family and 100 controls. The functional effect of mutant genes was investigated via bioinformatics analysis, including Polymorphism Phenotyping version2 (PolyPhen-2), Protein Variation Effect Analyzer (PROVEAN v1.1.3) Scale-Invariant Feature Transform (SIFT), and Mutation Taster. Results: In this three-generation family, a novel heterozygous mutation was found in the kinase domain of CRYBA1 gene (c.340C > T, p.R114C), which was only detected in patients in the family with inherited cataract and were not detected in the remained people in the family nor in normal people. The pathogenic effect of the mutation was verified via bioinformatics analysis. Conclusion: Our study presented the molecular experiments to confirm that a novel missense mutation of c.340 C > T located in exon 4 of CRYBA1 gene results in a bilateral coronary cataract with blue punctate opacities, which enriches the mutation spectrum of CRYBA1 gene in inherited cataract and deepens the understanding of the pathogenesis of inherited cataract.

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