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Li H, Liu G, Lu B, Zhou X. Novel compound heterozygous mutations in LEP responsible for obesity in a Chinese family. Mol Genet Metab Rep 2024; 40:101114. [PMID: 39041042 PMCID: PMC11261292 DOI: 10.1016/j.ymgmr.2024.101114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 06/25/2024] [Accepted: 06/26/2024] [Indexed: 07/24/2024] Open
Abstract
Background Early childhood obesity poses a significant global public health challenge, necessitating the identification of treatable causes, particularly congenital leptin deficiencies. Serum leptin level measurement aids in diagnosing these rare contributors, guiding effective management. Methods A Chinese family with early-onset obesity underwent LEP mutational screening via direct sequencing. mRNA expression and protein stability patterns of LEP were separately analyzed using qPCR and bioinformatics. Results We present a case of a 12.5-year-old girl born to non-obese, non-consanguineous Chinese parents, exhibiting low leptin levels. Leptin gene sequencing revealed novel compound heterozygous mutations in exon 3. RT-PCR analysis showed the mutation didn't affect leptin production. Bioinformatics analysis indicated the variant rendered the leptin protein unstable. Conclusion Loss-of-function mutations in LEP underlies early-onset obesity in the patient.
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Affiliation(s)
- Hui Li
- Department of Anesthesiology, Zibo Central Hospital, Binzhou Medical University, 255036 Zibo, China
| | - Guodong Liu
- Department of Gastroenterology, Zibo Central Hospital, Binzhou Medical University, 255036 Zibo, China
| | - Bei Lu
- Department of Nuclear Medicine and Radiotherapy, Zibo Central Hospital, Binzhou Medical University, 255036 Zibo, China
| | - Xin Zhou
- Department of Gastroenterology, Zibo Central Hospital, Binzhou Medical University, 255036 Zibo, China
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Wang KJ, Wang JX, Wang JD, Li M, Zhang JS, Mao YY, Wan XH. Congenital coralliform cataract is the predominant consequence of a recurrent mutation in the CRYGD gene. Orphanet J Rare Dis 2023; 18:200. [PMID: 37480084 PMCID: PMC10362579 DOI: 10.1186/s13023-023-02816-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 07/08/2023] [Indexed: 07/23/2023] Open
Abstract
BACKGROUND Congenital cataract is a leading cause of treatable childhood blindness and both clinically and genetically heterogeneous. Among the already characterized phenotypes, coralliform cataract is a rare special form of congenital cataracts. Although previous studies had shown that mutations in the γD-crystallin (CRYGD) can result in congenital coralliform cataracts, no conclusive genotype-phenotype correlation might be drawn. Here we aimed to identify the spectrum and frequency of CRYGD gene mutations in congenital coralliform cataracts of Chinese origin. METHODS The medical records of 392 Chinese families with congenital cataracts were reviewed between January 2011 and December 2021. The families, clinically documented to have congenital coralliform cataracts, were screened for mutations in candidate CRYGD gene. The genomic DNA of all subjects was extracted from peripheral blood leukocytes. PCR amplified and direct sequencing were performed to identify the disease-causing mutation. RESULTS A total of 12 families with coralliform cataracts were recruited in this study in the past 10 years, accounting for 3.1% of the families with congenital cataracts. Of the 12 families, all affected individuals presented with bilateral non-progressive coralliform cataracts since birth, with the best-corrected Snellen visual acuities ranging from 20/200 to 20/25. A recurrent c.70 C > A (p. P24T) mutation in CRYGD was identified in 10 families (83.3%) with congenital cataract, which co-segregated with all affected individuals and was not observed in unaffected family members or ethnically matched normal controls. CONCLUSIONS The coralliform cataract is characterized by being bilateral, non-progressive and present at birth. A recurrent p.P24T CRYGD mutation occurs independently in 83.3% of the Chinese families with congenital coralliform cataracts and most likely represents a mutational hot spot, which underscore the relations between coralliform cataract and p.P24T CRYGD.
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Affiliation(s)
- Kai-Jie Wang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Lab, 100730, Beijing, China
| | - Jue-Xue Wang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Lab, 100730, Beijing, China
| | - Jin-Da Wang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Lab, 100730, Beijing, China
| | - Meng Li
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Lab, 100730, Beijing, China
| | - Jing-Shang Zhang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Lab, 100730, Beijing, China
| | - Ying-Yan Mao
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Lab, 100730, Beijing, China
| | - Xiu-Hua Wan
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Lab, 100730, Beijing, China.
- NO.1 Dong Jiao Min Xiang, 100730, Beijing, China.
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Jarwar P, Waryah YM, Rafiq M, Waryah AM. Association of single nucleotide polymorphism variations in CRYAA and CRYAB genes with congenital cataract in Pakistani population. Saudi J Biol Sci 2022; 29:2727-2732. [PMID: 35531184 PMCID: PMC9073017 DOI: 10.1016/j.sjbs.2021.12.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 12/19/2021] [Accepted: 12/28/2021] [Indexed: 12/02/2022] Open
Abstract
Background The purpose of present study was to analyze the association of single nucleotide polymorphism (SNPs) variant in CRYAA and CRYAB genes with Congenital Cataract. Method Total 196 blood samples of children were collected, out of which 102 samples were congenital cataract (case group) and 94 samples were normal individuals (control group). Genomic DNA was extracted by using optimized inorganic method. Tetra primers for SNPs were designed and TETRA-ARMs assay was performed on both groups. Genotypic, allelic frequency and haplotype analyses were obtained by using SNPstats software. Results The coordination of genotypic and allelic frequencies of CRYAA and CRYAB genes variants and the association between case and control groups showed increased risk of congenital cataract in children who contained rs13053109 G > C variant of CRYAA in all models (all P > 0.05). This depicts the evident difference between the frequencies of case and control groups. The haplotype analysis of SNPs rs3761382, rs7278468 and rs13051039 of CRYAA gene showed weak linkage disequilibrium between the 3 SNPs (r2 < 0.8). The haplotype CTC indicated the high risk of congenital cataract in infants based of its p value (OR = 1.60 95% CI = 0.11-22.64, P > 0.05). Conclusion The variation in CRYAA gene can be the risk factor for congenital cataract in infants.
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Affiliation(s)
- Priya Jarwar
- Institute of Biotechnology and Genetic Engineering, University of Sindh, Jamshoro, Pakistan
| | - Yar Muhammad Waryah
- Scientific Ophthalmic and Research Laboratory, Sindh Institute of Ophthalmology and Visual Sciences, Hyderabad 71500, Pakistan
| | - Muhammad Rafiq
- Institute of Biotechnology and Genetic Engineering, University of Sindh, Jamshoro, Pakistan
| | - Ali Muhammad Waryah
- Department of Pathology, Liaquat University of Medical and Health Sciences, Jamshoro, Pakistan
- Department Molecular Biology and Genetics, Medical Research Center, Liaquat University of Medical and Health Sciences, Jamshoro, Pakistan
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Berry V, Ionides A, Pontikos N, Georgiou M, Yu J, Ocaka LA, Moore AT, Quinlan RA, Michaelides M. The genetic landscape of crystallins in congenital cataract. Orphanet J Rare Dis 2020; 15:333. [PMID: 33243271 PMCID: PMC7691105 DOI: 10.1186/s13023-020-01613-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 11/10/2020] [Indexed: 02/01/2023] Open
Abstract
Background The crystalline lens is mainly composed of a large family of soluble proteins called the crystallins, which are responsible for its development, growth, transparency and refractive index. Disease-causing sequence variants in the crystallins are responsible for nearly 50% of all non-syndromic inherited congenital cataracts, as well as causing cataract associated with other diseases, including myopathies. To date, more than 300 crystallin sequence variants causing cataract have been identified. Methods Here we aimed to identify the genetic basis of disease in five multi-generation British families and five sporadic cases with autosomal dominant congenital cataract using whole exome sequencing, with identified variants validated using Sanger sequencing. Following bioinformatics analysis, rare or novel variants with a moderate to damaging pathogenicity score, were filtered out and tested for segregation within the families. Results We have identified 10 different heterozygous crystallin variants. Five recurrent variants were found: family-A, with a missense variant (c.145C>T; p.R49C) in CRYAA associated with nuclear cataract; family-B, with a deletion in CRYBA1 (c.272delGAG; p.G91del) associated with nuclear cataract; and family-C, with a truncating variant in CRYGD (c.470G>A; W157*) causing a lamellar phenotype; individuals I and J had variants in CRYGC (c.13A>C; T5P) and in CRYGD (c.418C>T; R140*) causing unspecified congenital cataract and nuclear cataract, respectively. Five novel disease-causing variants were also identified: family D harboured a variant in CRYGC (c.179delG; R60Qfs*) responsible for a nuclear phenotype; family E, harboured a variant in CRYBB1 (c.656G>A; W219*) associated with lamellar cataract; individual F had a variant in CRYGD (c.392G>A; W131*) associated with nuclear cataract; and individuals G and H had variants in CRYAA (c.454delGCC; A152del) and in CRYBB1 (c.618C>A; Y206*) respectively, associated with unspecified congenital cataract. All novel variants were predicted to be pathogenic and to be moderately or highly damaging. Conclusions We report five novel variants and five known variants. Some are rare variants that have been reported previously in small ethnic groups but here we extend this to the wider population and record a broader phenotypic spectrum for these variants.
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Affiliation(s)
- Vanita Berry
- Department of Genetics, UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK. .,Moorfields Eye Hospital NHS Foundation Trust, London, EC1V 2PD, UK.
| | - Alex Ionides
- Moorfields Eye Hospital NHS Foundation Trust, London, EC1V 2PD, UK
| | - Nikolas Pontikos
- Department of Genetics, UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, EC1V 2PD, UK
| | - Michalis Georgiou
- Department of Genetics, UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, EC1V 2PD, UK
| | - Jing Yu
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX3 9DU, UK
| | - Louise A Ocaka
- GOSgene, Genetics and Genomic Medicine, UCL Great Ormond Street Institute of Child Health, London, WC1N 1EH, UK
| | - Anthony T Moore
- Moorfields Eye Hospital NHS Foundation Trust, London, EC1V 2PD, UK.,Ophthalmology Department, University of California School of Medicine, San Francisco, CA, 94158, USA
| | - Roy A Quinlan
- Department of Biosciences, University of Durham, Upper Mountjoy Science Site, Durham, DH1 3LE, UK
| | - Michel Michaelides
- Department of Genetics, UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK. .,Moorfields Eye Hospital NHS Foundation Trust, London, EC1V 2PD, UK.
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Molecular genetics of congenital cataracts. Exp Eye Res 2019; 191:107872. [PMID: 31770519 DOI: 10.1016/j.exer.2019.107872] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 11/12/2019] [Accepted: 11/13/2019] [Indexed: 12/18/2022]
Abstract
Congenital cataracts, the most common cause of visual impairment and blindness in children worldwide, have diverse etiologies. According to statistics analysis, about one quarter of congenital cataracts caused by genetic defects. Various mutations of more than one hundred genes have been identified in hereditary cataracts so far. In this review, we briefly summarize recent developments about the genetics, molecular mechanisms, and treatments of congenital cataracts. The studies of these pathogenic mutations and molecular genetics is making it possible for us to comprehend the underlying mechanisms of cataractogenesis and providing new insights into the preventive, diagnostic and therapeutic approaches of cataracts.
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Abstract
Posterior polar cataracts (PPC) have always been a challenge for cataract surgeons due to their inherently higher propensity for posterior capsule rupture. Over the years, several technical modifications have been suggested to enhance safety and reduce posterior capsule rupture rates in these polar cataracts. This review article tries to present the various techniques and strategies to published in literature to manage PPCs. It also discusses pearls for making surgery more reproducible and consistent, as well as the role of newer diagnostic and surgical technology based on the published literature on the subject.
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Rao Y, Dong S, Li Z, Yang G, Peng C, Yan M, Zheng F. A novel truncation mutation in CRYBB1 associated with autosomal dominant congenital cataract with nystagmus. Mol Vis 2017; 23:624-637. [PMID: 28928627 PMCID: PMC5595272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 08/31/2017] [Indexed: 11/18/2022] Open
Abstract
PURPOSE To identify the potential candidate genes for a large Chinese family with autosomal dominant congenital cataract (ADCC) and nystagmus, and investigate the possible molecular mechanism underlying the role of the candidate genes in cataractogenesis. METHODS We combined the linkage analysis and direct sequencing for the candidate genes in the linkage regions to identify the causative mutation. The molecular and bio-functional properties of the proteins encoded by the candidate genes was further explored with biophysical and biochemical studies of the recombinant wild-type and mutant proteins. RESULTS We identified a c. C749T (p.Q227X) transversion in exon 6 of CRYBB1, a cataract-causative gene. This nonsense mutation changes a phylogenetically conserved glutamine to a stop codon and is predicted to truncate the C-terminus of the wild-type protein by 26 amino acids. Comparison of the biophysical and biochemical properties of the recombinant full-length and truncated βB1-crystallins revealed that the mutation led to the insolubility and the phase separation phenomenon of the truncated protein with a changed conformation. Meanwhile, the thermal stability of the truncated βB1-crystallin was significantly decreased, and the mutation diminished the chaperoning ability of αA-crystallin with the mutant under heating stress. CONCLUSIONS Our findings highlight the importance of the C-terminus in βB1-crystallin in maintaining the crystalline function and stability, and provide a novel insight into the molecular mechanism underlying the pathogenesis of human autosomal dominant congenital cataract.
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Affiliation(s)
- Yan Rao
- Center for Gene Diagnosis, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Sufang Dong
- Center for Gene Diagnosis, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Zuhua Li
- Center for Gene Diagnosis, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Guohua Yang
- Department of Medical Genetics, School of Basic Medical Science, Wuhan University, Wuhan, China
| | - Chunyan Peng
- Center for Gene Diagnosis, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Ming Yan
- Department of Ophthalmology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Fang Zheng
- Center for Gene Diagnosis, Zhongnan Hospital of Wuhan University, Wuhan, China
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Messina-Baas O, Cuevas-Covarrubias SA. Inherited Congenital Cataract: A Guide to Suspect the Genetic Etiology in the Cataract Genesis. Mol Syndromol 2017; 8:58-78. [PMID: 28611546 DOI: 10.1159/000455752] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/05/2016] [Indexed: 01/23/2023] Open
Abstract
Cataracts are the principal cause of treatable blindness worldwide. Inherited congenital cataract (CC) shows all types of inheritance patterns in a syndromic and nonsyndromic form. There are more than 100 genes associated with cataract with a predominance of autosomal dominant inheritance. A cataract is defined as an opacity of the lens producing a variation of the refractive index of the lens. This variation derives from modifications in the lens structure resulting in light scattering, frequently a consequence of a significant concentration of high-molecular-weight protein aggregates. The aim of this review is to introduce a guide to identify the gene involved in inherited CC. Due to the manifold clinical and genetic heterogeneity, we discarded the cataract phenotype as a cardinal sign; a 4-group classification with the genes implicated in inherited CC is proposed. We consider that this classification will assist in identifying the probable gene involved in inherited CC.
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Zhuang X, Wang L, Song Z, Xiao W. A Novel Insertion Variant of CRYGD Is Associated with Congenital Nuclear Cataract in a Chinese Family. PLoS One 2015; 10:e0131471. [PMID: 26147294 PMCID: PMC4493073 DOI: 10.1371/journal.pone.0131471] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 06/02/2015] [Indexed: 01/13/2023] Open
Abstract
Objective To investigate a novel insertion variant of CRYGD identified in a Chinese family with nuclear congenital cataract. Methods A Chinese family with congenital nuclear cataract was recruited for the mutational screening of candidate genes by direct sequencing. Recombinant N-terminal Myc tagged wildtype or mutant CRYGD was expressed in HEK293T cells. The expression pattern, protein solubility and subcellular distribution were analyzed by western blotting and immunofluorescence. Principal Findings A novel insertion variant, c.451_452insGACT, in CRYGD was identified in the patients. It causes a frameshift and a premature termination of the polypeptide to become Y151*. A significantly reduced solubility was observed for this mutant. Unlike wildtype CRYGD, which existed mainly in the cytoplasm, Y151* was mis-located in the nucleus. Conclusions We have identified a novel mutation, c.451_452insGACT, in CRYGD, which is associated with nuclear cataract. This is the first insertion mutation of CRYGD found to cause autosomal dominant congenital cataract. The mutant protein, with loss of solubility and localization to the nucleus, is hypothesized to be the major cause of cataract in these patients.
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Affiliation(s)
- Xiaotong Zhuang
- Department of Ophthalmology, Shengjing Hospital, China Medical University, Shenyang, China
- Department of Ophthalmology, The Fourth People’s Hospital of Shenyang, Shenyang, China
| | - Lianqing Wang
- Department of Medical Genetics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, P. R. China
- Central Laboratory, Central Hospital of Zibo, Zibo, China
| | - Zixun Song
- Department of Ophthalmology, Shengjing Hospital, China Medical University, Shenyang, China
| | - Wei Xiao
- Department of Ophthalmology, Shengjing Hospital, China Medical University, Shenyang, China
- * E-mail:
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Serebryany E, King JA. The βγ-crystallins: native state stability and pathways to aggregation. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2014; 115:32-41. [PMID: 24835736 DOI: 10.1016/j.pbiomolbio.2014.05.002] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 04/30/2014] [Accepted: 05/02/2014] [Indexed: 01/26/2023]
Abstract
The βγ-crystallins are among the most stable and long-lived proteins in the human body. With increasing age, however, they transform to high molecular weight light-scattering aggregates, resulting in cataracts. This occurs despite the presence in the lens of high concentrations of the a-crystallin chaperones. Aggregation of crystallins can be induced in vitro by a variety of stresses, including acidic pH, ultraviolet light, oxidative damage, heating or freezing, and specific amino acid substitutions. Accumulating evidence points to the existence of specific biochemical pathways of protein: protein interaction and polymerization. We review the methods used for studying crystallin stability and aggregation and discuss the sometimes counterintuitive relationships between factors that favor native state stability and those that favor non-native aggregation. We discuss the behavior of βγ-crystallins in mixtures and their chaperone ability; the consequences of missense mutations and covalent damage to the side-chains; and the evolutionary strategies that have shaped these proteins. Efforts are ongoing to reveal the nature of cataractous crystallin aggregates and understand the mechanisms of aggregation in the context of key models of protein polymerization: amyloid, native-state, and domain-swapped. Such mechanistic understanding is likely to be of value for the development of therapeutic interventions and draw attention to unanswered questions about the relationship between a protein's native state stability and its transformation to an aggregated state.
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Affiliation(s)
- Eugene Serebryany
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Jonathan A King
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, United States.
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