1
|
Shiels A. Through the Cat-Map Gateway: A Brief History of Cataract Genetics. Genes (Basel) 2024; 15:785. [PMID: 38927721 PMCID: PMC11202810 DOI: 10.3390/genes15060785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 06/06/2024] [Accepted: 06/13/2024] [Indexed: 06/28/2024] Open
Abstract
Clouding of the transparent eye lens, or cataract(s), is a leading cause of visual impairment that requires surgical replacement with a synthetic intraocular lens to effectively restore clear vision. Most frequently, cataract is acquired with aging as a multifactorial or complex trait. Cataract may also be inherited as a classic Mendelian trait-often with an early or pediatric onset-with or without other ocular and/or systemic features. Since the early 1990s, over 85 genes and loci have been genetically associated with inherited and/or age-related forms of cataract. While many of these underlying genes-including those for lens crystallins, connexins, and transcription factors-recapitulate signature features of lens development and differentiation, an increasing cohort of unpredicted genes, including those involved in cell-signaling, membrane remodeling, and autophagy, has emerged-providing new insights regarding lens homeostasis and aging. This review provides a brief history of gene discovery for inherited and age-related forms of cataract compiled in the Cat-Map database and highlights potential gene-based therapeutic approaches to delay, reverse, or even prevent cataract formation that may help to reduce the increasing demand for cataract surgery.
Collapse
Affiliation(s)
- Alan Shiels
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA
| |
Collapse
|
2
|
Nicolas WJ, Shiriaeva A, Martynowycz MW, Grey AC, Ruma Y, Donaldson PJ, Gonen T. Structure of the lens MP20 mediated adhesive junction. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.13.594022. [PMID: 38798449 PMCID: PMC11118347 DOI: 10.1101/2024.05.13.594022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Human lens fiber membrane intrinsic protein MP20 is the second most abundant membrane protein of the human eye lens. Despite decades of effort its structure and function remained elusive. Here, we determined the MicroED structure of full-length human MP20 in lipidic-cubic phase to a resolution of 3.5 Å. MP20 forms tetramers each of which contain 4 transmembrane α-helices that are packed against one another forming a helical bundle. Both the N- and C- termini of MP20 are cytoplasmic. We found that each MP20 tetramer formed adhesive interactions with an opposing tetramer in a head-to-head fashion. These interactions were mediated by the extracellular loops of the protein. The dimensions of the MP20 adhesive junctions are consistent with the 11 nm thin lens junctions. Investigation of MP20 localization in human lenses indicated that in young fiber cells MP20 was stored intracellularly in vesicles and upon fiber cell maturation MP20 inserted into the plasma membrane and restricted the extracellular space. Together these results suggest that MP20 forms lens thin junctions in vivo confirming its role as a structural protein in the human eye lens, essential for its optical transparency.
Collapse
Affiliation(s)
- William J. Nicolas
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Howard Hughes Medical Institute, University of California, Los Angeles, CA 90095
| | - Anna Shiriaeva
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Michael W. Martynowycz
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Angus C Grey
- Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, NZ
| | - Yasmeen Ruma
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Howard Hughes Medical Institute, University of California, Los Angeles, CA 90095
| | - Paul J Donaldson
- Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, NZ
| | - Tamir Gonen
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Howard Hughes Medical Institute, University of California, Los Angeles, CA 90095
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| |
Collapse
|
3
|
Kong Y, Yi H, Li F, Duan X, Yang L, Fan X, Wu G, Ma M, Zha X, He Y. A novel missense mutation in the CRYBA2 caused autosomal dominant presenile cataract in a Chinese family. Mol Genet Genomics 2023:10.1007/s00438-023-02052-y. [PMID: 37438446 DOI: 10.1007/s00438-023-02052-y] [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: 01/12/2023] [Accepted: 06/25/2023] [Indexed: 07/14/2023]
Abstract
Presenile cataract is a relatively rare type of cataract, but its genetic mechanisms are currently not well understood. The precise identification of these causative genes is crucial for effective genetic counseling for patients and their families. The aim of our study was to identify the causative gene associated with presenile cataract in a Chinese family. In February 2020, a four-generation pedigree of presenile cataract patients was recruited at the 2nd Affiliated Hospital of Kunming Medical University. One patient and her healthy husband from the family underwent whole exome sequencing. The variant was validated through sanger sequencing, and co-segregation analysis was conducted in all family members to assess its pathogenicity. Molecular dynamics simulation (MDS) was used to analyze the conformation of both the wild type and pathogenic mutant loci p.Y153H of CRYBA2. We identified presenile cataract in the pedigree, which follows an autosomal-dominant pattern of inheritance. The family includes five clinically affected patients who all developed presenile cataract between the ages from 24 to 30. We confirmed the pathogenicity of a heterozygous missense variant (NM_057093:c.457T >C) in CRYBA2 within this family. The affected amino acid demonstrates high conservation across species. Subsequent sanger sequencing confirmed co-segregation of the disease in all family members. MDS analysis revealed that the p.Y153H mutant disrupted hydrogen bond formation between Y153 and R193 within the two β-strands of the fourth Greek key domain, leading to destabilization of the βA2-crystallin. In conclusion, a novel causative mutation (NM_057093:c.457T>C) in CRYBA2 might contribute to autosomal dominant presenile cataract.
Collapse
Affiliation(s)
- Yanbo Kong
- Department of Ophthalmology, The 2nd Affiliated Hospital of Kunming Medical University, Kunming, 650500, Yunnan, China
| | - Haoan Yi
- Department of Cell Biology and Medical Genetics, Faculty of Basic Medical Science, Kunming Medical University, Kunming, 650500, Yunnan, China
| | - Fan Li
- Department of Pathology and Pathophysiology, School of Medicine, Yunnan University, Kunming, 650500, Yunnan, China
| | - Xiu Duan
- Department of Cell Biology and Medical Genetics, Faculty of Basic Medical Science, Kunming Medical University, Kunming, 650500, Yunnan, China
| | - Lipu Yang
- Department of Cell Biology and Medical Genetics, Faculty of Basic Medical Science, Kunming Medical University, Kunming, 650500, Yunnan, China
| | - Xinyu Fan
- Department of Ophthalmology, The 2nd Affiliated Hospital of Kunming Medical University, Kunming, 650500, Yunnan, China
| | - Guojiu Wu
- Department of Ophthalmology, The 2nd Affiliated Hospital of Kunming Medical University, Kunming, 650500, Yunnan, China
| | - Minjun Ma
- Department of Ophthalmology, The 2nd Affiliated Hospital of Kunming Medical University, Kunming, 650500, Yunnan, China
| | - Xu Zha
- Department of Ophthalmology, The 2nd Affiliated Hospital of Kunming Medical University, Kunming, 650500, Yunnan, China.
| | - Yongshu He
- Department of Cell Biology and Medical Genetics, Faculty of Basic Medical Science, Kunming Medical University, Kunming, 650500, Yunnan, China.
| |
Collapse
|
4
|
Berry V, Fujinami K, Mochizuki K, Iwata T, Pontikos N, Quinlan RA, Michaelides M. A recurrent variant in LIM2 causes an isolated congenital sutural/lamellar cataract in a Japanese family. Ophthalmic Genet 2022; 43:622-626. [PMID: 35736209 PMCID: PMC9612932 DOI: 10.1080/13816810.2022.2090010] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background Genetically determined cataract is both clinically and molecularly highly heterogeneous. Here, we have identified a heterozygous variant in the lens integral membrane protein LIM2, the second most abundant protein in the lens, responsible for congenital sutural/lamellar cataract in a three-generation Japanese family. Methods Whole exome sequencing (WES) was undertaken in one affected and one unaffected individual from a family with autosomal dominant congenital cataract to establish the underlying genetic basis. Results A recurrent missense variant LIM2: c.388C>T; p.R130C was identified and found to co-segregate with disease. In addition, one variant COL11A1:c.3788C>T of unknown significance (VUS) was also identified. Conclusions We report a variant in LIM2 causing an isolated autosomal-dominant congenital sutural/lamellar cataract in a Japanese family. This is the first report of a LIM2 variant in the Japanese population. Hence, we expand the mutation spectrum of LIM2 variants in different ethnic groups.
Collapse
Affiliation(s)
- Vanita Berry
- Department of Genetics, UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Kaoru Fujinami
- Department of Genetics, UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK.,Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization, Tokyo Medical Centre, Tokyo, Japan
| | - Kiyofumi Mochizuki
- Department of Ophthalmology, Gifu University Graduate School of Medicine, Gifu, Japan
| | - Takeshi Iwata
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
| | - Nikolas Pontikos
- Department of Genetics, UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Roy A Quinlan
- Department of Biosciences, University of Durham, Durham, UK
| | - Michel Michaelides
- Department of Genetics, UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| |
Collapse
|
5
|
Shiels A, Hejtmancik JF. Inherited cataracts: Genetic mechanisms and pathways new and old. Exp Eye Res 2021; 209:108662. [PMID: 34126080 PMCID: PMC8595562 DOI: 10.1016/j.exer.2021.108662] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/13/2021] [Accepted: 06/01/2021] [Indexed: 12/15/2022]
Abstract
Cataract(s) is the clinical equivalent of lens opacity and is caused by light scattering either by high molecular weight protein aggregates in lens cells or disruption of the lens microarchitecture itself. Genetic mutations underlying inherited cataract can provide insight into the biological processes and pathways critical for lens homeostasis and transparency, classically including the lens crystallins, connexins, membrane proteins or components, and intermediate filament proteins. More recently, cataract genes have been expanded to include newly identified biological processes such as chaperone or protein degradation components, transcription or growth factors, channels active in the lens circulation, and collagen and extracellular matrix components. Cataracts can be classified by age, and in general congenital cataracts are caused by severe mutations resulting in major damage to lens proteins, while age related cataracts are associated with variants that merely destabilize proteins thereby increasing susceptibility to environmental insults over time. Thus there might be separate pathways to opacity for congenital and age-related cataracts whereby congenital cataracts induce the unfolded protein response (UPR) and apoptosis to destroy the lens microarchitecture, while in age related cataract high molecular weight (HMW) aggregates formed by denatured crystallins bound by α-crystallin result in light scattering without severe damage to the lens microarchitecture.
Collapse
Affiliation(s)
- Alan Shiels
- Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, 63110, USA.
| | - J Fielding Hejtmancik
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892-1860, USA.
| |
Collapse
|
6
|
Barashkov NA, Konovalov FA, Borisova TV, Teryutin FM, Solovyev AV, Pshennikova VG, Sapojnikova NV, Vychuzhina LS, Romanov GP, Gotovtsev NN, Morozov IV, Bondar AA, Platonov FA, Burtseva TE, Khusnutdinova EK, Posukh OL, Fedorova SA. Autosomal recessive cataract (CTRCT18) in the Yakut population isolate of Eastern Siberia: a novel founder variant in the FYCO1 gene. Eur J Hum Genet 2021; 29:965-976. [PMID: 33767456 PMCID: PMC8187664 DOI: 10.1038/s41431-021-00833-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 12/19/2020] [Accepted: 02/10/2021] [Indexed: 11/09/2022] Open
Abstract
Congenital autosomal recessive cataract with unknown genetic etiology is one of the most common Mendelian diseases among the Turkic-speaking Yakut population (Eastern Siberia, Russia). To identify the genetic cause of congenital cataract spread in this population, we performed whole-exome sequencing (Illumina NextSeq 500) in one Yakut family with three affected siblings whose parents had preserved vision. We have revealed the novel homozygous c.1621C>T transition leading to premature stop codon p.(Gln541*) in exon 8 of the FYCO1 gene (NM_024513.4). Subsequent screening of c.1621C>T p.(Gln541*) revealed this variant in a homozygous state in 25 out of 29 Yakut families with congenital cataract (86%). Among 424 healthy individuals from seven populations of Eastern Siberia (Russians, Yakuts, Evenks, Evens, Dolgans, Chukchi, and Yukaghirs), the highest carrier frequency of c.1621C>T p.(Gln541*) was found in the Yakut population (7.9%). DNA samples of 25 homozygous for c.1621C>T p.(Gln541*) patients with congenital cataract and 114 unaffected unrelated individuals without this variant were used for a haplotype analysis based on the genotyping of six STR markers (D3S3512, D3S3685, D3S3582, D3S3561, D3S1289, and D3S3698). The structure of the identified haplotypes indicates a common origin for all of the studied mutant chromosomes bearing c.1621C>T p.(Gln541*). The age of the с.1621C>T p.(Gln541*) founder haplotype was estimated to be approximately 260 ± 65 years (10 generations). These findings characterize Eastern Siberia as the region of the world with the most extensive accumulation of the unique variant c.1621C>T p.(Gln541*) in the FYCO1 gene as a result of the founder effect.
Collapse
Affiliation(s)
- Nikolay A Barashkov
- Laboratory of Molecular Genetics, Yakut Science Centre of Complex Medical Problems, Yakutsk, Russian Federation.
- Laboratory of Molecular Biology, M.K. Ammosov North-Eastern Federal University, Yakutsk, Russian Federation.
| | | | - Tuyara V Borisova
- Laboratory of Molecular Biology, M.K. Ammosov North-Eastern Federal University, Yakutsk, Russian Federation
| | - Fedor M Teryutin
- Laboratory of Molecular Genetics, Yakut Science Centre of Complex Medical Problems, Yakutsk, Russian Federation
| | - Aisen V Solovyev
- Laboratory of Molecular Genetics, Yakut Science Centre of Complex Medical Problems, Yakutsk, Russian Federation
- Laboratory of Molecular Biology, M.K. Ammosov North-Eastern Federal University, Yakutsk, Russian Federation
| | - Vera G Pshennikova
- Laboratory of Molecular Genetics, Yakut Science Centre of Complex Medical Problems, Yakutsk, Russian Federation
| | - Nadejda V Sapojnikova
- Department of Ophthalmology, Republican Hospital #1 - National Centre of Medicine, Yakutsk, Russian Federation
| | - Lyubov S Vychuzhina
- Department of Ophthalmology, Republican Hospital #1 - National Centre of Medicine, Yakutsk, Russian Federation
| | - Georgii P Romanov
- Laboratory of Molecular Genetics, Yakut Science Centre of Complex Medical Problems, Yakutsk, Russian Federation
- Laboratory of Molecular Biology, M.K. Ammosov North-Eastern Federal University, Yakutsk, Russian Federation
| | - Nyurgun N Gotovtsev
- Laboratory of Molecular Genetics, Yakut Science Centre of Complex Medical Problems, Yakutsk, Russian Federation
| | - Igor V Morozov
- SB RAS Genomics Core Facility, Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russian Federation
- Novosibirsk State University, Novosibirsk, Russian Federation
| | - Alexander A Bondar
- SB RAS Genomics Core Facility, Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russian Federation
| | - Fedor A Platonov
- Medical Institute, M.K. Ammosov North-Eastern Federal University, Yakutsk, Russian Federation
| | - Tatiana E Burtseva
- Medical Institute, M.K. Ammosov North-Eastern Federal University, Yakutsk, Russian Federation
- Laboratory of the Children Health Monitoring and Medical-environmental Research, Yakut Science Centre of Complex Medical Problems, Yakutsk, Russian Federation
| | - Elza K Khusnutdinova
- Laboratory of Molecular Biology, M.K. Ammosov North-Eastern Federal University, Yakutsk, Russian Federation
- Laboratory of Human Molecular Genetics, Institute of Biochemistry and Genetics, Ufa Federal Research Center of Russian Academy of Sciences, Ufa, Russian Federation
- Department of Genetics and Fundamental Medicine, Bashkir State University, Ufa, Russian Federation
| | - Olga L Posukh
- Novosibirsk State University, Novosibirsk, Russian Federation
- Federal Research Center Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russian Federation
| | - Sardana A Fedorova
- Laboratory of Molecular Genetics, Yakut Science Centre of Complex Medical Problems, Yakutsk, Russian Federation
- Laboratory of Molecular Biology, M.K. Ammosov North-Eastern Federal University, Yakutsk, Russian Federation
| |
Collapse
|
7
|
Wang X, Qin Y, Abudoukeremuahong A, Dongye M, Zhang X, Wang D, Li J, Lin Z, Yang Y, Ding L, Lin H. Elongated axial length and myopia-related fundus changes associated with the Arg130Cys mutation in the LIM2 gene in four Chinese families with congenital cataracts. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:235. [PMID: 33708862 PMCID: PMC7940952 DOI: 10.21037/atm-20-4275] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Background Congenital cataract (CC) is a congenital abnormality characterized by lens opacity present at birth and is associated with highly heterogeneous clinical manifestations. Lens-specific integral membrane protein (LIM2) gene expression is localized to tight junctional domains of different lens fiber membranes. To date, only four mutations in LIM2 have been reported to be associated with congenital or presenile cataracts. Due to the rarity of variants detected in the gene, there is limited progress in understanding the correlation between the genotype and phenotype of patients with mutations in LIM2. Methods A total of four Chinese families with CCs were recruited for this study, including three families inheriting in an autosomal dominant (AD) pattern and one sporadic case. Genomic DNA was extracted from the leukocytes of peripheral blood collected from all available patients. Whole-exome sequencing (WES) was performed on all probands and at least one of their parents. Bioinformatics analysis was performed to evaluate the pathogenicity of the candidate variants. Exon 4 of LIM2 was amplified by polymerase chain reaction and directly sequenced. All patients underwent full ocular examinations. This was an observational study to explore the genotype-phenotype relationships in the four families with a common candidate variant. Results Various ocular phenotypes were detected in these families, mainly including CCs, elongated axial length, and myopia-related fundus changes. The LIM2 gene mutation, p.Arg130Cys, was detected in all patients. This was further confirmed by Sanger sequencing. The proportion of probands with this mutation in our CCs database was 3.1% (4/130), which indicated that this mutation appears to be a frequent cause of cataracts in the Han Chinese population. This variation has been reported by other investigators before and was correlated with isolated cataracts. Conclusions This is the first study that reports various ocular phenotypes associated with the p.Arg130Cys mutation in the LIM2 gene, which indicated the phenotypic heterogeneity of this gene. LIM2 might not only function as an integral membrane protein in lens fiber cells but also be associated with the axial development of the eyeball. Functional studies of the LIM2 gene are important and should receive more attention.
Collapse
Affiliation(s)
- Xun Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yanli Qin
- Department of Ophthalmology, People's Hospital of Xinjiang Uygur Autonomous Region, Urumqi, China
| | | | - Meimei Dongye
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xulin Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Dongni Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jing Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Zhuoling Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yahan Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Lin Ding
- Department of Ophthalmology, People's Hospital of Xinjiang Uygur Autonomous Region, Urumqi, China
| | - Haotian Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| |
Collapse
|
8
|
Pei R, Liang PF, Ye W, Li J, Ma JY, Zhou J. A novel mutation of LIM2 causes autosomal dominant membranous cataract in a Chinese family. Int J Ophthalmol 2020; 13:1512-1520. [PMID: 33078099 DOI: 10.18240/ijo.2020.10.02] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 07/02/2020] [Indexed: 11/23/2022] Open
Abstract
AIM To identify mutations in the genes of a four-generation Chinese family with congenital membranous cataracts and investigate the morphologic changes and possible functional damage underlying the role of the mutant gene. METHODS Whole exome analysis of thirteen members of a four-generation pedigree affected with congenital membranous cataracts was performed; co-segregation analysis of identified variants was validated by Sanger sequencing. All members underwent detailed physical and complete eye examinations. The physical changes caused by the mutation were analyzed in silico through homology modeling. The lens fiber block from a patient was observed under a scanning electron microscope (SEM). Cell membrane proteins and cytoplasmic proteins from the human lenses donated by one patient with cataract in this family and from the dislocated lens resulted from the penetrating ocular trauma of a patient unrelated with this family were extracted, and the expression and localization of MP20 and Cx46 were detected by Western blot (WB) assay in these proteins. RESULTS A novel LIM2 heterozygous mutation (c.388C>T, p.R130C) was identified with congenital membranous cataracts inherited by an autosomal dominant (AD) pattern. Nystagmus and amblyopia were observed in all patients of this family, and exotropia and long axial length were observed in most patients. A/B ultrasound scan and ultrasound biomicroscopy revealed obvious thin crystalline lenses from 1.7 to 2.7 mm in central thickness in all cataract eyes. The bioinformatic analysis showed that the mutation was deleterious to the physiological function of LIM2-encoded MP20. Furthermore, by SEM, ultrastructure of the cataract nucleus showed that lens fiber cells (LFCs) remained morphologic characteristics of immature fiber cells, including flap cell surface with straight edges and lacking normal ball-and-socket joint boundaries, which implied that the differentiation of LFCs might be inhibited. Accumulation of MP20 and Cx46 in the cytoplasm was observed in the cytoplasm of the LFCs in human cataract lens. CONCLUSION We identify a novel heterozygous LIM2 (c.388C>T, p.R130C) mutation inherited by an AD pattern. This LIM2 mutation causes the abnormal sub-localization of MP20 and Cx46 in LFCs resulting in membranous cataracts.
Collapse
Affiliation(s)
- Rui Pei
- Department of Ophthalmology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, Shaanxi Province, China
| | - Peng-Fei Liang
- Department of Otolaryngology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, Shaanxi Province, China
| | - Wei Ye
- Department of Ophthalmology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, Shaanxi Province, China
| | - Ji Li
- Department of Ophthalmology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, Shaanxi Province, China
| | - Ji-Yuan Ma
- Department of Ophthalmology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, Shaanxi Province, China
| | - Jian Zhou
- Department of Ophthalmology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, Shaanxi Province, China
| |
Collapse
|
9
|
Berry V, Georgiou M, Fujinami K, Quinlan R, Moore A, Michaelides M. Inherited cataracts: molecular genetics, clinical features, disease mechanisms and novel therapeutic approaches. Br J Ophthalmol 2020; 104:1331-1337. [PMID: 32217542 DOI: 10.1136/bjophthalmol-2019-315282] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 11/20/2019] [Accepted: 01/28/2020] [Indexed: 02/01/2023]
Abstract
Cataract is the most common cause of blindness in the world; during infancy and early childhood, it frequently results in visual impairment. Congenital cataracts are phenotypically and genotypically heterogeneous and can occur in isolation or in association with other systemic disorders. Significant progress has been made in identifying the molecular genetic basis of cataract; 115 genes to date have been found to be associated with syndromic and non-syndromic cataract and 38 disease-causing genes have been identified to date to be associated with isolated cataract. In this review, we briefly discuss lens development and cataractogenesis, detail the variable cataract phenotypes and molecular mechanisms, including genotype-phenotype correlations, and explore future novel therapeutic avenues including cellular therapies and pharmacological treatments.
Collapse
Affiliation(s)
- Vanita Berry
- Department of Genetics, UCL Institute of Ophthalmology, University College London, London, UK
| | - Michalis Georgiou
- Department of Genetics, UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Kaoru Fujinami
- Department of Genetics, UCL Institute of Ophthalmology, University College London, London, UK.,National Institute of Sensory Organs, National Hospital Organization, Tokyo Medical Centre, Tokyo, Japan
| | - Roy Quinlan
- Department of Genetics, UCL Institute of Ophthalmology, University College London, London, UK.,Department of Biosciences, School of Biological and Medical Sciences, University of Durham, Durham, UK
| | - Anthony Moore
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.,Ophthalmology Department, University of California School of Medicine, San Francisco, California, USA
| | - Michel Michaelides
- Department of Genetics, UCL Institute of Ophthalmology, University College London, London, UK .,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| |
Collapse
|
10
|
Berry V, Pontikos N, Dudakova L, Moore AT, Quinlan R, Liskova P, Michaelides M. A novel missense mutation in LIM2 causing isolated autosomal dominant congenital cataract. Ophthalmic Genet 2020; 41:131-134. [PMID: 32202185 DOI: 10.1080/13816810.2020.1737950] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Background: Congenital cataract is the most common cause of blindness in the world. Congenital cataracts are clinically and genetically heterogeneous and are mostly inherited in an autosomal dominant fashion. We identified the genetic cause of isolated autosomal dominant cataract in a four-generation British family and a Czech family.Methods: Whole exome sequencing (WES) was performed on one affected member in the British family and two affected members in the Czech family.Results: A novel missense variant c.388C > T; p.(R130C) was identified in the Lens integral membrane protein (LIM2) and found to co-segregate with disease in both families.Conclusions: Here we report the first autosomal dominant congenital cataract variant p.(R130C) in LIM2, causing a non-syndromic pulverulent and nuclear phenotype in European families.
Collapse
Affiliation(s)
- Vanita Berry
- UCL Institute of Ophthalmology, University College London, London, UK
| | - Nikolas Pontikos
- UCL Institute of Ophthalmology, University College London, London, UK.,Department of Genetics, Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Lubica Dudakova
- Research Unit for Rare Diseases, Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Anthony T Moore
- UCL Institute of Ophthalmology, University College London, London, UK.,Ophthalmology Department, University of California School of Medicine, San Francisco, California, USA
| | - Roy Quinlan
- School of Biological and Medical Sciences, University of Durham, Durham, UK
| | - Petra Liskova
- Research Unit for Rare Diseases, Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic.,Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, UK.,Department of Genetics, Moorfields Eye Hospital NHS Foundation Trust, London, UK
| |
Collapse
|
11
|
Liu P, Edassery SL, Ali L, Thomson BR, Savas JN, Jin J. Long-lived metabolic enzymes in the crystalline lens identified by pulse-labeling of mice and mass spectrometry. eLife 2019; 8:50170. [PMID: 31820737 PMCID: PMC6914337 DOI: 10.7554/elife.50170] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 12/04/2019] [Indexed: 01/29/2023] Open
Abstract
The lenticular fiber cells are comprised of extremely long-lived proteins while still maintaining an active biochemical state. Dysregulation of these activities has been implicated in diseases such as age-related cataracts. However, the lenticular protein dynamics underlying health and disease is unclear. We sought to measure the global protein turnover rates in the eye using nitrogen-15 labeling of mice and mass spectrometry. We measured the 14N/15N-peptide ratios of 248 lens proteins, including Crystallin, Aquaporin, Collagen and enzymes that catalyze glycolysis and oxidation/reduction reactions. Direct comparison of lens cortex versus nucleus revealed little or no 15N-protein contents in most nuclear proteins, while there were a broad range of 14N/15N ratios in cortex proteins. Unexpectedly, like Crystallins, many enzymes with relatively high abundance in nucleus were also exceedingly long-lived. The slow replacement of these enzymes in spite of young age of mice suggests their potential roles in age-related metabolic changes in the lens.
Collapse
Affiliation(s)
- Pan Liu
- Feinberg Cardiovascular and Renal Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Seby Louis Edassery
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Laith Ali
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Benjamin R Thomson
- Feinberg Cardiovascular and Renal Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Jeffrey N Savas
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Jing Jin
- Feinberg Cardiovascular and Renal Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, United States
| |
Collapse
|
12
|
Jiao X, Khan SY, Kaul H, Butt T, Naeem MA, Riazuddin S, Hejtmancik JF, Riazuddin SA. Autosomal recessive congenital cataracts linked to HSF4 in a consanguineous Pakistani family. PLoS One 2019; 14:e0225010. [PMID: 31815953 PMCID: PMC6901218 DOI: 10.1371/journal.pone.0225010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 10/25/2019] [Indexed: 11/17/2022] Open
Abstract
PURPOSE To investigate the genetic basis of autosomal recessive congenital cataracts (arCC) in a large consanguineous Pakistani family. METHODS All participating members of family, PKCC074 underwent an ophthalmic examination. Slit-lamp photographs were ascertained for affected individuals that have not been operated for the removal of the cataractous lens. A small aliquot of the blood sample was collected from all participating individuals and genomic DNAs were extracted. A genome-wide scan was performed with polymorphic short tandem repeat (STR) markers and the logarithm of odds (LOD) scores were calculated. All coding exons and exon-intron boundaries of HSF4 were sequenced and expression of Hsf4 in mouse ocular lens was investigated. The C-terminal FLAG-tagged wild-type and mutant HSF4b constructs were prepared to examine the nuclear localization pattern of the mutant protein. RESULTS The ophthalmological examinations suggested that nuclear cataracts are present in affected individuals. Genome-wide linkage analyses localized the critical interval to a 10.95 cM (14.17 Mb) interval on chromosome 16q with a maximum two-point LOD score of 4.51 at θ = 0. Sanger sequencing identified a novel missense mutation: c.433G>C (p.Ala145Pro) that segregated with the disease phenotype in the family and was not present in ethnically matched controls. Real-time PCR analysis identified the expression of HSF4 in mouse lens as early as embryonic day 15 with a steady level of expression thereafter. The immunofluorescence tracking confirmed that both wild-type and mutant HSF4 (p.Ala145Pro) proteins localized to the nucleus. CONCLUSION Here, we report a novel missense mutation in HSF4 associated with arCC in a familial case of Pakistani descent.
Collapse
Affiliation(s)
- Xiaodong Jiao
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Shahid Y Khan
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Haiba Kaul
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Tariq Butt
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Muhammad Asif Naeem
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Sheikh Riazuddin
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan.,Allama Iqbal Medical College, University of Health Sciences, Lahore, Pakistan
| | - J Fielding Hejtmancik
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - S Amer Riazuddin
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| |
Collapse
|
13
|
Abstract
Cataract, the clinical correlate of opacity or light scattering in the eye lens, is usually caused by the presence of high-molecular-weight (HMW) protein aggregates or disruption of the lens microarchitecture. In general, genes involved in inherited cataracts reflect important processes and pathways in the lens including lens crystallins, connexins, growth factors, membrane proteins, intermediate filament proteins, and chaperones. Usually, mutations causing severe damage to proteins cause congenital cataracts, while milder variants increasing susceptibility to environmental insults are associated with age-related cataracts. These may have different pathogenic mechanisms: Congenital cataracts induce the unfolded protein response and apoptosis. By contrast, denatured crystallins in age-related cataracts are bound by α-crystallin and form light-scattering HMW aggregates. New therapeutic approaches to age-related cataracts use chemical chaperones to solubilize HMW aggregates, while attempts are being made to regenerate lenses using endogenous stem cells to treat congenital cataracts.
Collapse
Affiliation(s)
- Alan Shiels
- Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri 63110, USA;
| | - J Fielding Hejtmancik
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892-1860, USA;
| |
Collapse
|
14
|
Zhou Z, Li L, Lu L, Min L. Identification of a missense mutation in MIP gene via mutation analysis of a Guangxi Zhuang ethnic pedigree with congenital nuclear cataracts. Exp Ther Med 2018; 16:3256-3260. [PMID: 30214549 DOI: 10.3892/etm.2018.6557] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Accepted: 06/29/2018] [Indexed: 01/04/2023] Open
Abstract
At present, congenital cataract is the world's leading cause of blindness among children. The aim of the present study was to determine and analyze the genetic disorder associated with a congenital nuclear cataract in a three-generation family of Guangxi Zhuang ethnicity. A total of 3 affected individuals and 5 unaffected family members underwent appropriate comprehensive medical examinations, mainly of the eyes. The white blood cells of the family members were collected and genomic DNA was extracted from 100 healthy individuals, as the control group. The sequences of candidate genes were determined by polymerase chain reaction amplification followed by direct sequencing. The functional consequences of the mutation were analysed with biology software. A missense mutation (c.97C>T) was found in exon 1 of major intrinsic protein of lens fiber (MIP) gene. Therefore, the arginine of the highly conserved codon 33 was changed to cysteine. This mutation was identified in the affected family members, but not identified in unaffected family members or the 100 normal controls. The mutation in the MIP gene is the genetic cause of the congenital cataract in the ethnic Guangxi Zhuang family.
Collapse
Affiliation(s)
- Zhou Zhou
- Department of Ophthalmology, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi 530021, P.R. China
| | - Li Li
- Department of Ophthalmology, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi 530021, P.R. China
| | - Lu Lu
- Department of Ophthalmology, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi 530021, P.R. China
| | - Li Min
- Department of Ophthalmology, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi 530021, P.R. China
| |
Collapse
|
15
|
Reis LM, Semina EV. Genetic landscape of isolated pediatric cataracts: extreme heterogeneity and variable inheritance patterns within genes. Hum Genet 2018; 138:847-863. [PMID: 30187164 DOI: 10.1007/s00439-018-1932-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 08/29/2018] [Indexed: 12/12/2022]
Abstract
Pediatric cataract represents an important cause of pediatric visual impairment. While both genetic and environmental causes for pediatric cataract are known, a large proportion remains idiopathic. The purpose of this review is to discuss genes involved in isolated pediatric cataract, with a focus on variable inheritance patterns within genes. Mutations in over 52 genes are known to cause isolated pediatric cataract, with a major contribution from genes encoding for crystallins, transcription factors, membrane proteins, and cytoskeletal proteins. Interestingly, both dominant and recessive inheritance patterns have been reported for mutations in 13 different cataract genes. For some genes, dominant and recessive alleles represent distinct types of mutations, but for many, especially missense variants, there are no clear patterns to distinguish between dominant and recessive alleles. Further research into the functional effects of these mutations, as well as additional data on the frequency of the identified variants, is needed to clarify variant pathogenicity. Exome sequencing continues to be successful in identifying novel genes associated with congenital cataract but is hindered by the extreme genetic heterogeneity of this condition. The large number of idiopathic cases suggests that more genes and potentially novel mechanisms of gene disruption remain to be identified.
Collapse
Affiliation(s)
- Linda M Reis
- Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Elena V Semina
- Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin, Milwaukee, WI, 53226, USA. .,Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.
| |
Collapse
|
16
|
Javadiyan S, Craig JE, Souzeau E, Sharma S, Lower KM, Mackey DA, Staffieri SE, Elder JE, Taranath D, Straga T, Black J, Pater J, Casey T, Hewitt AW, Burdon KP. High-Throughput Genetic Screening of 51 Pediatric Cataract Genes Identifies Causative Mutations in Inherited Pediatric Cataract in South Eastern Australia. G3 (BETHESDA, MD.) 2017; 7:3257-3268. [PMID: 28839118 PMCID: PMC5633377 DOI: 10.1534/g3.117.300109] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Accepted: 08/15/2017] [Indexed: 01/09/2023]
Abstract
Pediatric cataract is a leading cause of childhood blindness. This study aimed to determine the genetic cause of pediatric cataract in Australian families by screening known disease-associated genes using massively parallel sequencing technology. We sequenced 51 previously reported pediatric cataract genes in 33 affected individuals with a family history (cases with previously known or published mutations were excluded) using the Ion Torrent Personal Genome Machine. Variants were prioritized for validation if they were predicted to alter the protein sequence and were absent or rare with minor allele frequency <1% in public databases. Confirmed mutations were assessed for segregation with the phenotype in all available family members. All identified novel or previously reported cataract-causing mutations were screened in 326 unrelated Australian controls. We detected 11 novel mutations in GJA3, GJA8, CRYAA, CRYBB2, CRYGS, CRYGA, GCNT2, CRYGA, and MIP; and three previously reported cataract-causing mutations in GJA8, CRYAA, and CRYBB2 The most commonly mutated genes were those coding for gap junctions and crystallin proteins. Including previous reports of pediatric cataract-associated mutations in our Australian cohort, known genes account for >60% of familial pediatric cataract in Australia, indicating that still more causative genes remain to be identified.
Collapse
Affiliation(s)
- Shari Javadiyan
- Department of Ophthalmology, School of Medicine, Flinders University, Adelaide, South Australia 5042, Australia
| | - Jamie E Craig
- Department of Ophthalmology, School of Medicine, Flinders University, Adelaide, South Australia 5042, Australia
| | - Emmanuelle Souzeau
- Department of Ophthalmology, School of Medicine, Flinders University, Adelaide, South Australia 5042, Australia
| | - Shiwani Sharma
- Department of Ophthalmology, School of Medicine, Flinders University, Adelaide, South Australia 5042, Australia
| | - Karen M Lower
- Department of Haematology and Genetic Pathology, School of Medicine, Flinders University, Adelaide, South Australia 5042, Australia
| | - David A Mackey
- Centre for Ophthalmology and Visual Science, University of Western Australia, Lions Eye Institute, Perth, Western Australia 6009, Australia
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria 3002, Australia
- Department of Surgery, University of Melbourne, Victoria 3010, Australia
| | - Sandra E Staffieri
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria 3002, Australia
- Department of Surgery, University of Melbourne, Victoria 3010, Australia
- Department of Ophthalmology, Royal Children's Hospital, Melbourne, Victoria 3052, Australia
| | - James E Elder
- Department of Surgery, University of Melbourne, Victoria 3010, Australia
- Department of Ophthalmology, Royal Children's Hospital, Melbourne, Victoria 3052, Australia
| | - Deepa Taranath
- Department of Ophthalmology, School of Medicine, Flinders University, Adelaide, South Australia 5042, Australia
| | - Tania Straga
- Ophthalmology Department, Women's and Children's Hospital, Adelaide, South Australia 5006, Australia
| | - Joanna Black
- Ophthalmology Department, Women's and Children's Hospital, Adelaide, South Australia 5006, Australia
| | - John Pater
- Ophthalmology Department, Women's and Children's Hospital, Adelaide, South Australia 5006, Australia
| | - Theresa Casey
- Ophthalmology Department, Women's and Children's Hospital, Adelaide, South Australia 5006, Australia
| | - Alex W Hewitt
- Department of Surgery, University of Melbourne, Victoria 3010, Australia
- Ophthalmology Department, Women's and Children's Hospital, Adelaide, South Australia 5006, Australia
- Department of Paediatrics, University of Melbourne, Victoria 3010, Australia
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania 7000, Australia
| | - Kathryn P Burdon
- Department of Ophthalmology, School of Medicine, Flinders University, Adelaide, South Australia 5042, Australia
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania 7000, Australia
| |
Collapse
|
17
|
Zhu X, Zhang S, Chang R, Lu Y. New cataract markers: Mechanisms of disease. Clin Chim Acta 2017; 472:41-45. [PMID: 28705775 DOI: 10.1016/j.cca.2017.07.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 07/08/2017] [Accepted: 07/09/2017] [Indexed: 11/28/2022]
Abstract
Cataract is caused by nutritional, metabolic, environmental, and genetic factors, and is a significant cause of blindness and visual impairment. In recent years, extensive research into the human genome has revealed that numerous genetic mutations are associated with cataract. These mutations affect a variety of genes, including those encoding crystallin, membrane proteins, cytoskeletal proteins, transcription factors, and metabolism-related proteins. Elucidation of these mutations and the genetic and molecular mechanisms has helped clarify the etiology of cataract and may facilitate its early diagnosis and treatment. This review summarizes recent advances in our knowledge and potential clinical of genetic markers of cataract.
Collapse
Affiliation(s)
- Xiangjia Zhu
- Department of Ophthalmology, Eye and Ear, Nose, and Throat Hospital, Fudan University, 83 Fenyang Road, Shanghai 200031, People's Republic of China; Eye Institute, Eye and Ear, Nose, and Throat Hospital of Fudan University, 83 Fenyang Road, Shanghai 200031, People's Republic of China; Key Laboratory of Myopia, Ministry of Health, Shanghai 200031, People's Republic of China; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai 200031, People's Republic of China
| | - Shaohua Zhang
- Department of Ophthalmology, Eye and Ear, Nose, and Throat Hospital, Fudan University, 83 Fenyang Road, Shanghai 200031, People's Republic of China; Eye Institute, Eye and Ear, Nose, and Throat Hospital of Fudan University, 83 Fenyang Road, Shanghai 200031, People's Republic of China; Key Laboratory of Myopia, Ministry of Health, Shanghai 200031, People's Republic of China; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai 200031, People's Republic of China
| | - Ruiqi Chang
- Department of Ophthalmology, Eye and Ear, Nose, and Throat Hospital, Fudan University, 83 Fenyang Road, Shanghai 200031, People's Republic of China; Eye Institute, Eye and Ear, Nose, and Throat Hospital of Fudan University, 83 Fenyang Road, Shanghai 200031, People's Republic of China; Key Laboratory of Myopia, Ministry of Health, Shanghai 200031, People's Republic of China; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai 200031, People's Republic of China
| | - Yi Lu
- Department of Ophthalmology, Eye and Ear, Nose, and Throat Hospital, Fudan University, 83 Fenyang Road, Shanghai 200031, People's Republic of China; Eye Institute, Eye and Ear, Nose, and Throat Hospital of Fudan University, 83 Fenyang Road, Shanghai 200031, People's Republic of China; Key Laboratory of Myopia, Ministry of Health, Shanghai 200031, People's Republic of China; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai 200031, People's Republic of China.
| |
Collapse
|
18
|
Fine mapping of chromosome 9 locus associated with congenital cataract. Int Ophthalmol 2017; 38:1187-1192. [PMID: 28585112 DOI: 10.1007/s10792-017-0581-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 05/31/2017] [Indexed: 10/19/2022]
Abstract
PURPOSE The purpose of this study was to study the molecular basis of inherited autosomal recessive cataracts in Pakistan population and to identify the molecular defect segregating with the disease phenotype. METHODS Families having two or more affected individuals were identified through hospital, blood samples were collected and DNA was extracted. We employed the traditional strategy of linkage analysis using M13-labeled primers to map the already known genes for autosomal recessive cataract. Statistically, the data were evaluated through LOD score. RESULTS Ten families affected with autosomal receive congenital cataract were enrolled for this study. Overall, three families were linked to reported loci for autosomal recessive congenital cataract. Out of these, one family Bl05 was linked to a cataract locus at 9q13. Fine mapping of the chromosome 9 locus considerably delimited the previously reported linkage interval from 13.99 to 7.99 cM in this study. CONCLUSION Our results reduced the linkage interval of previously reported cataract locus on chromosome 9, thus considerably reducing the number of candidate genes.
Collapse
|
19
|
Kristiansen E, Revold T, Lingaas F, Narfström K, Pedersen PB, Kielland C, Dahl S, Ropstad EO. Cataracts in the Norwegian Buhund-current prevalence and characteristics. Vet Ophthalmol 2017; 20:460-467. [PMID: 28044393 DOI: 10.1111/vop.12449] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To evaluate prevalence and characteristics of cataracts in the Norwegian Buhund breed 20 years after high reported prevalence of especially pulverulent nuclear cataracts (PNCs). ANIMALS STUDIED Two hundred and fifty Norwegian Buhund dogs in Norway, Sweden, and Denmark (117 males and 133 females) with previously unknown eye health status were included. Forty-five dogs had multiple examinations (two to six times over a 6-year period). Median age was 4.4 years [0.2-15.2] at first examination and 5.3 years [0.2-15.2] at last examination. PROCEDURES All dogs underwent regular screening for inherited eye diseases. RESULTS At the last observation of each dog, 52.4% were affected by PNC, categorized as minimal (33 of 250 dogs; 13.2%), mild (31 dogs; 12.4%), moderate (38 dogs; 15.2%), or pronounced (29 dogs; 11.6%). Moderate or pronounced changes were only seen in older dogs, and progressive changes were identified in some of the re-examined dogs. Some dogs, free of lenticular changes at early examinations, were affected by PNC at re-examinations. The odds for finding PNC increased with dog's age up to approximately 8 years. Presumably inherited cataracts other than PNC were found in 53 dogs (21.2%) with cortical (17.6%) and posterior polar (6.4%) locations as the most common ones. CONCLUSIONS The high prevalence of PNC in the breed reported 20 years ago persists. PNCs are not always visible in young dogs, and the rate of progression varies. The prevalence of other types of cataract is also high, but cataracts rarely cause loss of vision in this breed.
Collapse
Affiliation(s)
| | - Tobias Revold
- Department of Companion Animal Clinical Sciences, Norwegian University of Life Sciences, Oslo, Norway
| | - Frode Lingaas
- Department of Companion Animal Clinical Sciences, Norwegian University of Life Sciences, Oslo, Norway
| | - Kristina Narfström
- College of Veterinary Medicine, University of Missouri, Colombia, MO, USA.,RetVet KB, Vaxholm, Sweden
| | | | - Camilla Kielland
- Department of Companion Animal Clinical Sciences, Norwegian University of Life Sciences, Oslo, Norway
| | | | - Ernst-Otto Ropstad
- Department of Companion Animal Clinical Sciences, Norwegian University of Life Sciences, Oslo, Norway
| |
Collapse
|
20
|
Zhu P, Li W, Ni M, Zhang C, Liu S, Wu Q, Jiang W, Zhang J, Zhang M, Li X, Cui Y, Xue C, Xia X. The P20R mutation of αB-crystallin diminishes its anti-apoptotic activity in human lens epithelial cells. Biochem Biophys Res Commun 2016; 483:463-467. [PMID: 28007594 DOI: 10.1016/j.bbrc.2016.12.121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 12/19/2016] [Indexed: 10/20/2022]
Abstract
αB-crystallin acts as an anti-apoptosis protein in human lens epithelial (HLE) cells. We recently identified a missense mutation in αB-crystallin that changes proline 20 to an arginine (P20R) in a Chinese family with autosomal dominant congenital posterior polar cataract. The impact of the P20R mutation on the anti-apoptosis function remains unclear. To explore the anti-apoptotic activity of αB-crystallin wild type (αB-wt) and its P20R mutant under oxidative stress, HLE cells were transfected with αB-wt and αB-P20R constructs and expression was measured by western blotting. Flow cytometry and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP digoxigenin nick end-labelling (TUNEL) staining were performed to investigate apoptosis. We found that αB-wt performed a dominant role in inhibiting stress-induced apoptosis, but this function was impeded in cells expressing αB-P20R. The P20R mutant of αB-crystallin exhibits diminished anti-apoptotic activity compared with the native protein.
Collapse
Affiliation(s)
- Peiran Zhu
- Jinling Hospital, School of Medicine, Nanjing University, Nanjing, 210002, PR China
| | - Weiwei Li
- Jinling Hospital, School of Medicine, Nanjing University, Nanjing, 210002, PR China
| | - Mengxia Ni
- Jinling Hospital, School of Medicine, Nanjing University, Nanjing, 210002, PR China
| | - Cui Zhang
- Jinling Hospital, School of Medicine, Nanjing University, Nanjing, 210002, PR China
| | - Shuaimei Liu
- Jinling Hospital, School of Medicine, Nanjing University, Nanjing, 210002, PR China
| | - Qiuyue Wu
- Jinling Hospital, School of Medicine, Nanjing University, Nanjing, 210002, PR China
| | - Weijun Jiang
- Jinling Hospital, School of Medicine, Nanjing University, Nanjing, 210002, PR China
| | - Jing Zhang
- Jinling Hospital, School of Medicine, Nanjing University, Nanjing, 210002, PR China
| | - Mingchao Zhang
- Jinling Hospital, School of Medicine, Nanjing University, Nanjing, 210002, PR China
| | - Xiaojun Li
- Jinling Hospital, School of Medicine, Nanjing University, Nanjing, 210002, PR China
| | - Yingxia Cui
- Jinling Hospital, School of Medicine, Nanjing University, Nanjing, 210002, PR China
| | - Chunyan Xue
- Jinling Hospital, School of Medicine, Nanjing University, Nanjing, 210002, PR China
| | - Xinyi Xia
- Jinling Hospital, School of Medicine, Nanjing University, Nanjing, 210002, PR China.
| |
Collapse
|
21
|
Irum B, Khan SY, Ali M, Daud M, Kabir F, Rauf B, Fatima F, Iqbal H, Khan AO, Al Obaisi S, Naeem MA, Nasir IA, Khan SN, Husnain T, Riazuddin S, Akram J, Eghrari AO, Riazuddin SA. Deletion at the GCNT2 Locus Causes Autosomal Recessive Congenital Cataracts. PLoS One 2016; 11:e0167562. [PMID: 27936067 PMCID: PMC5147899 DOI: 10.1371/journal.pone.0167562] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 11/16/2016] [Indexed: 11/25/2022] Open
Abstract
PURPOSE The aim of this study is to identify the molecular basis of autosomal recessive congenital cataracts (arCC) in a large consanguineous pedigree. METHODS All participating individuals underwent a detailed ophthalmic examination. Each patient's medical history, particularly of cataracts and other ocular abnormalities, was compiled from available medical records and interviews with family elders. Blood samples were donated by all participating family members and used to extract genomic DNA. Genetic analysis was performed to rule out linkage to known arCC loci and genes. Whole-exome sequencing libraries were prepared and paired-end sequenced. A large deletion was found that segregated with arCC in the family, and chromosome walking was conducted to estimate the proximal and distal boundaries of the deletion mutation. RESULTS Exclusion and linkage analysis suggested linkage to a region of chromosome 6p24 harboring GCNT2 (glucosaminyl (N-acetyl) transferase 2) with a two-point logarithm of odds score of 5.78. PCR amplifications of the coding exons of GCNT2 failed in individuals with arCC, and whole-exome data analysis revealed a large deletion on chromosome 6p in the region harboring GCNT2. Chromosomal walking using multiple primer pairs delineated the extent of the deletion to approximately 190 kb. Interestingly, a failure to amplify a junctional fragment of the deletion break strongly suggests an insertion in addition to the large deletion. CONCLUSION Here, we report a novel insertion/deletion mutation at the GCNT2 locus that is responsible for congenital cataracts in a large consanguineous family.
Collapse
Affiliation(s)
- Bushra Irum
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Shahid Y. Khan
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Muhammad Ali
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Muhammad Daud
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Firoz Kabir
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Bushra Rauf
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Fareeha Fatima
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Hira Iqbal
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Arif O. Khan
- King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
| | - Saif Al Obaisi
- King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
| | - Muhammad Asif Naeem
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Idrees A. Nasir
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Shaheen N. Khan
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Tayyab Husnain
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Sheikh Riazuddin
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
- Allama Iqbal Medical College, University of Health Sciences, Lahore, Pakistan
- National Centre for Genetic Diseases, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - Javed Akram
- Allama Iqbal Medical College, University of Health Sciences, Lahore, Pakistan
- National Centre for Genetic Diseases, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - Allen O. Eghrari
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - S. Amer Riazuddin
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| |
Collapse
|
22
|
Irum B, Khan SY, Ali M, Kaul H, Kabir F, Rauf B, Fatima F, Nadeem R, Khan AO, Al Obaisi S, Naeem MA, Nasir IA, Khan SN, Husnain T, Riazuddin S, Akram J, Eghrari AO, Riazuddin SA. Mutation in LIM2 Is Responsible for Autosomal Recessive Congenital Cataracts. PLoS One 2016; 11:e0162620. [PMID: 27814360 PMCID: PMC5096708 DOI: 10.1371/journal.pone.0162620] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 08/25/2016] [Indexed: 11/20/2022] Open
Abstract
Purpose To identify the molecular basis of non-syndromic autosomal recessive congenital cataracts (arCC) in a consanguineous family. Methods All family members participating in the study received a comprehensive ophthalmic examination to determine their ocular phenotype and contributed a blood sample, from which genomic DNA was extracted. Available medical records and interviews with the family were used to compile the medical history of the family. The symptomatic history of the individuals exhibiting cataracts was confirmed by slit-lamp biomicroscopy. A genome-wide linkage analysis was performed to localize the disease interval. The candidate gene, LIM2 (lens intrinsic membrane protein 2), was sequenced bi-directionally to identify the disease-causing mutation. The physical changes caused by the mutation were analyzed in silico through homology modeling, mutation and bioinformatic algorithms, and evolutionary conservation databases. The physiological importance of LIM2 to ocular development was assessed in vivo by real-time expression analysis of Lim2 in a mouse model. Results Ophthalmic examination confirmed the diagnosis of nuclear cataracts in the affected members of the family; the inheritance pattern and cataract development in early infancy indicated arCC. Genome-wide linkage analysis localized the critical interval to chromosome 19q with a two-point logarithm of odds (LOD) score of 3.25. Bidirectional sequencing identified a novel missense mutation, c.233G>A (p.G78D) in LIM2. This mutation segregated with the disease phenotype and was absent in 192 ethnically matched control chromosomes. In silico analysis predicted lower hydropathicity and hydrophobicity but higher polarity of the mutant LIM2-encoded protein (MP19) compared to the wild-type. Moreover, these analyses predicted that the mutation would disrupt the secondary structure of a transmembrane domain of MP19. The expression of Lim2, which was detected in the mouse lens as early as embryonic day 15 (E15) increased after birth to a level that was sustained through the postnatal time points. Conclusion A novel missense mutation in LIM2 is responsible for autosomal recessive congenital cataracts.
Collapse
Affiliation(s)
- Bushra Irum
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, United States of America
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, 53700, Pakistan
| | - Shahid Y. Khan
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, United States of America
| | - Muhammad Ali
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, United States of America
| | - Haiba Kaul
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, United States of America
| | - Firoz Kabir
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, United States of America
| | - Bushra Rauf
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, United States of America
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, 53700, Pakistan
| | - Fareeha Fatima
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, 53700, Pakistan
| | - Raheela Nadeem
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, 53700, Pakistan
| | - Arif O. Khan
- King Khaled Eye Specialist Hospital, Riyadh, 12329, Saudi Arabia
| | - Saif Al Obaisi
- King Khaled Eye Specialist Hospital, Riyadh, 12329, Saudi Arabia
| | - Muhammad Asif Naeem
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, 53700, Pakistan
| | - Idrees A. Nasir
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, 53700, Pakistan
| | - Shaheen N. Khan
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, 53700, Pakistan
| | - Tayyab Husnain
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, 53700, Pakistan
| | - Sheikh Riazuddin
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, 53700, Pakistan
- Allama Iqbal Medical College, University of Health Sciences, Lahore, 54550, Pakistan
- National Centre for Genetic Diseases, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, 44000, Pakistan
| | - Javed Akram
- Allama Iqbal Medical College, University of Health Sciences, Lahore, 54550, Pakistan
- National Centre for Genetic Diseases, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, 44000, Pakistan
| | - Allen O. Eghrari
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, United States of America
| | - S. Amer Riazuddin
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, United States of America
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, United States of America
- * E-mail:
| |
Collapse
|
23
|
Young A, Dandekar U, Pan C, Sader A, Zheng JJ, Lewis RA, Farber DB. GNAI3: Another Candidate Gene to Screen in Persons with Ocular Albinism. PLoS One 2016; 11:e0162273. [PMID: 27607449 PMCID: PMC5015898 DOI: 10.1371/journal.pone.0162273] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 08/21/2016] [Indexed: 11/18/2022] Open
Abstract
Ocular albinism type 1 (OA), caused by mutations in the OA1 gene, encodes a G-protein coupled receptor, OA1, localized in melanosomal membranes of the retinal pigment epithelium (RPE). This disorder is characterized by both RPE macro-melanosomes and abnormal decussation of ganglion cell axons at the brain's optic chiasm. We demonstrated previously that Oa1 specifically activates Gαi3, which also signals in the Oa1 transduction pathway that regulates melanosomal biogenesis. In this study, we screened the human Gαi3 gene, GNAI3, in DNA samples from 26 patients who had all clinical characteristics of OA but in whom a specific mutation in the OA1 gene had not been found, and in 6 normal control individuals. Using the Agilent HaloPlex Target Enrichment System and next-generation sequencing (NGS) on the Illumina MiSeq platform, we identified 518 variants after rigorous filtering. Many of these variants were corroborated by Sanger sequencing. Overall, 98.8% coverage of the GNAI3 gene was obtained by the HaloPlex amplicons. Of all variants, 6 non-synonymous and 3 synonymous were in exons, 41 in a non-coding exon embedded in the 3' untranslated region (UTR), 6 in the 5' UTR, and 462 in introns. These variants included novel SNVs, insertions, deletions, and a frameshift mutation. All were found in at least one patient but none in control samples. Using computational methods, we modeled the GNAI3 protein and its non-synonymous exonic mutations and determined that several of these may be the cause of disease in the patients studied. Thus, we have identified GNAI3 as a second gene possibly responsible for X-linked ocular albinism.
Collapse
Affiliation(s)
- Alejandra Young
- Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine, UCLA, Los Angeles, CA, United States of America
- Molecular Biology Institute, UCLA, Los Angeles, CA, United States of America
| | - Uma Dandekar
- UCLA-GenoSeq Core, UCLA, Los Angeles, CA, United States of America
| | - Calvin Pan
- UCLA-GenoSeq Core, UCLA, Los Angeles, CA, United States of America
| | - Avery Sader
- Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine, UCLA, Los Angeles, CA, United States of America
| | - Jie J. Zheng
- Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine, UCLA, Los Angeles, CA, United States of America
| | - Richard A. Lewis
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States of America
| | - Debora B. Farber
- Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine, UCLA, Los Angeles, CA, United States of America
- Molecular Biology Institute, UCLA, Los Angeles, CA, United States of America
- Brain Research Institute, UCLA, Los Angeles, CA, United States of America
- * E-mail:
| |
Collapse
|
24
|
Jiao X, Kabir F, Irum B, Khan AO, Wang Q, Li D, Khan AA, Husnain T, Akram J, Riazuddin S, Hejtmancik JF, Riazuddin SA. A Common Ancestral Mutation in CRYBB3 Identified in Multiple Consanguineous Families with Congenital Cataracts. PLoS One 2016; 11:e0157005. [PMID: 27326458 PMCID: PMC4915718 DOI: 10.1371/journal.pone.0157005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 05/22/2016] [Indexed: 11/19/2022] Open
Abstract
PURPOSE This study was performed to investigate the genetic determinants of autosomal recessive congenital cataracts in large consanguineous families. METHODS Affected individuals underwent a detailed ophthalmological examination and slit-lamp photographs of the cataractous lenses were obtained. An aliquot of blood was collected from all participating family members and genomic DNA was extracted from white blood cells. Initially, a genome-wide scan was performed with genomic DNAs of family PKCC025 followed by exclusion analysis of our familial cohort of congenital cataracts. Protein-coding exons of CRYBB1, CRYBB2, CRYBB3, and CRYBA4 were sequenced bidirectionally. A haplotype was constructed with SNPs flanking the causal mutation for affected individuals in all four families, while the probability that the four familial cases have a common founder was estimated using EM and CHM-based algorithms. The expression of Crybb3 in the developing murine lens was investigated using TaqMan assays. RESULTS The clinical and ophthalmological examinations suggested that all affected individuals had nuclear cataracts. Genome-wide linkage analysis localized the causal phenotype in family PKCC025 to chromosome 22q with statistically significant two-point logarithm of odds (LOD) scores. Subsequently, we localized three additional families, PKCC063, PKCC131, and PKCC168 to chromosome 22q. Bidirectional Sanger sequencing identified a missense variation: c.493G>C (p.Gly165Arg) in CRYBB3 that segregated with the disease phenotype in all four familial cases. This variation was not found in ethnically matched control chromosomes, the NHLBI exome variant server, or the 1000 Genomes or dbSNP databases. Interestingly, all four families harbor a unique disease haplotype that strongly suggests a common founder of the causal mutation (p<1.64E-10). We observed expression of Crybb3 in the mouse lens as early as embryonic day 15 (E15), and expression remained relatively steady throughout development. CONCLUSION Here, we report a common ancestral mutation in CRYBB3 associated with autosomal recessive congenital cataracts identified in four familial cases of Pakistani origin.
Collapse
Affiliation(s)
- Xiaodong Jiao
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, United States of America
| | - Firoz Kabir
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, United States of America
| | - Bushra Irum
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, United States of America
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, 53700, Pakistan
| | - Arif O. Khan
- King Khaled Eye Specialist Hospital, Riyadh, 12329, Saudi Arabia
| | - Qiwei Wang
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, United States of America
| | - David Li
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, United States of America
| | - Asma A. Khan
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, 53700, Pakistan
| | - Tayyab Husnain
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, 53700, Pakistan
| | - Javed Akram
- Allama Iqbal Medical College, University of Health Sciences, Lahore, 54550, Pakistan
- National Centre for Genetic Diseases, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - Sheikh Riazuddin
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, 53700, Pakistan
- Allama Iqbal Medical College, University of Health Sciences, Lahore, 54550, Pakistan
- National Centre for Genetic Diseases, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - J. Fielding Hejtmancik
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, United States of America
| | - S. Amer Riazuddin
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, United States of America
- * E-mail:
| |
Collapse
|
25
|
Sousounis K, Qi F, Yadav MC, Millán JL, Toyama F, Chiba C, Eguchi Y, Eguchi G, Tsonis PA. A robust transcriptional program in newts undergoing multiple events of lens regeneration throughout their lifespan. eLife 2015; 4. [PMID: 26523389 PMCID: PMC4739772 DOI: 10.7554/elife.09594] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Accepted: 11/01/2015] [Indexed: 12/14/2022] Open
Abstract
Newts have the ability to repeatedly regenerate their lens even during ageing. However, it is unclear whether this regeneration reflects an undisturbed genetic activity. To answer this question, we compared the transcriptomes of lenses, irises and tails from aged newts that had undergone lens regeneration 19 times with the equivalent tissues from young newts that had never experienced lens regeneration. Our analysis indicates that repeatedly regenerated lenses showed a robust transcriptional program comparable to young never-regenerated lenses. In contrast, the tail, which was never regenerated, showed gene expression signatures of ageing. Our analysis strongly suggests that, with respect to gene expression, the regenerated lenses have not deviated from a robust transcriptional program even after multiple events of regeneration throughout the life of the newt. In addition, our study provides a new paradigm in biology, and establishes the newt as a key model for the study of regeneration in relation to ageing. DOI:http://dx.doi.org/10.7554/eLife.09594.001 Newts are unusual animals because they are able to regenerate injured or lost body parts. To regenerate the lens in an eye, certain cells in the iris need to change into lens cells. In 2011, a group of researchers reported the results of a 16-year long study of lens regeneration in Japanese newts. This study found that lenses from old newts that have undergone lens regeneration many times are structurally identical to those of young individuals that still have their original lenses. Also, many genes required to make lens proteins were expressed at similar levels in the lenses of the old and young newts. Therefore, even old newts retain the ability to fully regenerate their lenses. However, it is possible that the lenses in the old newts might show more subtle signs of ageing in the form of differences in the expression of other genes. Here, Sousounis et al. – including some of the researchers from the 2011 work – used an approach called transcriptomics to examine the patterns of gene expression in this group of newts in more detail. Sousounis et al. collected cells from the lenses, irises and tails of both the old and young newts. The experiments show that the patterns of gene expression in the regenerated lenses closely resemble the patterns seen in the lenses of the young newts. In contrast, the tail cells of the old and young newts display different gene expression patterns, with those from the older newts displaying hallmarks of ageing that are absent in the younger newts. The iris cells from the old newts show a mixed gene expression profile with features characteristic of both young and aged tissue. Sousounis et al.’s findings highlight the value of using newts as models to study the links between regeneration and ageing DOI:http://dx.doi.org/10.7554/eLife.09594.002
Collapse
Affiliation(s)
| | - Feng Qi
- Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, United States
| | - Manisha C Yadav
- Sanford Children's Health Research Center, Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, United States
| | - José Luis Millán
- Sanford Children's Health Research Center, Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, United States
| | - Fubito Toyama
- Graduate School of Engineering, Utsunomiya University, Utsunomiya, Japan
| | - Chikafumi Chiba
- Faculty of Life and Environmental Sciences, Tsukuba University, Tsukuba, Japan
| | - Yukiko Eguchi
- National Institute for Basic Biology, National Institutes for Natural Sciences, Okazaki, Japan
| | - Goro Eguchi
- National Institute for Basic Biology, National Institutes for Natural Sciences, Okazaki, Japan
| | - Panagiotis A Tsonis
- Department of Biology, University of Dayton, Dayton, United States.,Sanford Children's Health Research Center, Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, United States
| |
Collapse
|
26
|
Jiaox X, Khan SY, Irum B, Khan AO, Wang Q, Kabir F, Khan AA, Husnain T, Akram J, Riazuddin S, Hejtmancik JF, Riazuddin SA. Missense Mutations in CRYAB Are Liable for Recessive Congenital Cataracts. PLoS One 2015; 10:e0137973. [PMID: 26402864 PMCID: PMC4581838 DOI: 10.1371/journal.pone.0137973] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 08/25/2015] [Indexed: 11/19/2022] Open
Abstract
PURPOSE This study was initiated to identify causal mutations responsible for autosomal recessive congenital cataracts in consanguineous familial cases. METHODS Affected individuals underwent a detailed ophthalmological and clinical examination, and slit-lamp photographs were ascertained for affected individuals who have not yet been operated for the removal of the cataractous lens. Blood samples were obtained, and genomic DNA was extracted from white blood cells. A genome-wide scan was completed with short tandem repeat (STR) markers, and the logarithm of odds (LOD) scores were calculated. Protein coding exons of CRYAB were sequenced, bi-directionally. Evolutionary conservation was investigated by aligning CRYAB orthologues, and the expression of Cryab in embryonic and postnatal mice lens was investigated with TaqMan probe. RESULTS The clinical and ophthalmological examinations suggested that all affected individuals had nuclear cataracts. Genome-wide linkage analysis suggested a potential region on chromosome 11q23 harboring CRYAB. DNA sequencing identified a missense variation: c.34C>T (p.R12C) in CRYAB that segregated with the disease phenotype in the family. Subsequent interrogation of our entire cohort of familial cases identified a second familial case localized to chromosome 11q23 harboring a c.31C>T (p.R11C) mutation. In silico analyses suggested that the mutations identified in familial cases, p.R11C and p.R12C will not be tolerated by the three-dimensional structure of CRYAB. Real-time PCR analysis identified the expression of Cryab in mouse lens as early as embryonic day 15 (E15) that increased significantly until postnatal day 6 (P6) with steady level of expression thereafter. CONCLUSION Here, we report two novel missense mutations, p.R11C and p.R12C, in CRYAB associated with autosomal recessive congenital nuclear cataracts.
Collapse
Affiliation(s)
- Xiaodong Jiaox
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, United States of America
| | - Shahid Y. Khan
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, United States of America
| | - Bushra Irum
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, United States of America
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, 53700, Pakistan
| | - Arif O. Khan
- King Khaled Eye Specialist Hospital, Riyadh, 12329, Saudi Arabia
| | - Qiwei Wang
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, United States of America
| | - Firoz Kabir
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, United States of America
| | - Asma A. Khan
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, 53700, Pakistan
| | - Tayyab Husnain
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, 53700, Pakistan
| | - Javed Akram
- Allama Iqbal Medical College, University of Health Sciences, Lahore, 54550, Pakistan
- National Centre for Genetic Diseases, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - Sheikh Riazuddin
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, 53700, Pakistan
- Allama Iqbal Medical College, University of Health Sciences, Lahore, 54550, Pakistan
- National Centre for Genetic Diseases, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - J. Fielding Hejtmancik
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, United States of America
| | - S. Amer Riazuddin
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, United States of America
- * E-mail:
| |
Collapse
|
27
|
SIPA1L3 identified by linkage analysis and whole-exome sequencing as a novel gene for autosomal recessive congenital cataract. Eur J Hum Genet 2015; 23:1627-33. [PMID: 25804400 DOI: 10.1038/ejhg.2015.46] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 02/10/2015] [Accepted: 02/11/2015] [Indexed: 12/25/2022] Open
Abstract
Congenital cataract (CC) is one of the most important causes for blindness or visual impairment in infancy. A substantial proportion of isolated CCs has monogenic causes. The disease is genetically heterogeneous, and all Mendelian modes of inheritance have been reported. We mapped a locus for isolated CC on 19p13.1-q13.2 in a distantly consanguineous German family with two sisters affected by dense white cataracts. Whole-exome sequencing identified a homozygous nonsense variant c.4489C>T (p.(R1497*)) in SIPA1L3 (signal-induced proliferation-associated 1 like 3) in both affected children. SIPA1L3 encodes a GTPase-activating protein (GAP), which interacts with small GTPases of the Rap family via its Rap-GAP-domain. The suggested role of Rap GTPases in cell growth, differentiation and organization of the cytoskeleton in the human lens, and lens-enriched expression of the murine ortholog gene Sipa1l3 in embryonic mice indicates that this gene is crucial for early lens development. Our results provide evidence that sequence variants in human SIPA1L3 cause autosomal recessive isolated CC and give new insight into the molecular pathogenesis underlying human cataracts.
Collapse
|
28
|
A novel MIP gene mutation analysis in a Chinese family affected with congenital progressive punctate cataract. PLoS One 2014; 9:e102733. [PMID: 25033405 PMCID: PMC4102541 DOI: 10.1371/journal.pone.0102733] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 06/23/2014] [Indexed: 02/01/2023] Open
Abstract
Congenital cataracts are one of the leading causes of visual impairment and blindness in children, and genetic factors play an important role in their development. This study aimed to identify the genetic defects associated with autosomal dominant congenital progressive punctate cataracts in a Chinese family and to explore the potential pathogenesis. Detailed family history and clinical data were recorded, and all the family members’ blood samples were collected for DNA extraction. Linkage analysis was performed by microsatellite markers that are associated with punctate cataracts, and logarithm (base 10) of odds (LOD) scores were calculated using the LINKAGE program. Positive two-point LOD scores were obtained at markers D12S1622 (Zmax = 2.71 at θ = 0.0), D12S1724 (Zmax = 2.71 at θ = 0.0), and D12S90 (Zmax = 2.71 at θ = 0.0), which flank the major intrinsic protein of lens fiber (MIP) gene on chromosomal region 12q13. Direct sequencing of the encoding region of the MIP gene revealed a novel mutation (G>D) in exon 4 at nucleotide 644, which caused a substitution of glycine to aspartic acid at codon 215 (p.G215D) for the MIP protein. The mutation cosegregated with all patients with congenital progressive punctate cataracts, but it was absent in the healthy members. Bioinformatics analysis predicted that the mutation affects the function of the MIP protein. The wild type (WT) and G215D mutant of MIP were transfected with green fluorescent protein (GFP) into Hela cells separately, and it was found that the G215D mutant was aberrantly located in the cytoplasm instead of in the plasma membrane. In summary, our study presented genetic and functional evidence linking the new MIP mutation of G215D to autosomal dominant congenital cataracts, which adds to the list of MIP mutations linked to congenital progressive punctate cataracts.
Collapse
|
29
|
Abstract
Amblyopia is a neurodevelopmental disorder of vision associated with decreased visual acuity, poor or absent stereopsis, and suppression of information from one eye.(1,2) Amblyopia may be caused by strabismus (strabismic amblyopia), refractive error (anisometropic amblyopia), or deprivation from obstructed vision (deprivation amblyopia). 1 In the developed world, amblyopia is the most common cause of childhood visual impairment, 3 which reduces quality of life 4 and also almost doubles the lifetime risk of legal blindness.(5, 6) Successful treatment of amblyopia greatly depends on early detection and treatment of predisposing disorders such as congenital cataract, which is the most common cause of deprivational amblyopia. Understanding the genetic causes of congenital cataract leads to more effective screening tests, early detection and treatment of infants and children who are at high risk for hereditary congenital cataract.
Collapse
Affiliation(s)
- Behzad Mansouri
- Mass Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston , Massachusetts , USA and
| | | | | | | |
Collapse
|
30
|
Liu Q, Wang KJ, Zhu SQ. A novel p.G112E mutation in BFSP2 associated with autosomal dominant pulverulent cataract with sutural opacities. Curr Eye Res 2014; 39:1013-9. [PMID: 24654948 DOI: 10.3109/02713683.2014.891749] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To identify the genetic defect in a Chinese family with bilateral pulverulent sutural cataract. MATERIALS AND METHODS A three-generation family with congenital cataract was recruited in the study. The study protocol followed the principles of the Declaration of Helsinki. Detailed family history and clinical data were recorded. Genomic DNA was extracted from peripheral blood leukocytes. Candidate gene sequencing was performed to identify the disease-causing mutation. The effects of amino acid changes on the structure and function of proteins were predicted by bioinformatics analysis. RESULTS All affected individuals presented pulverulent opacities in the embryonal nucleus and sutures. Direct candidate gene sequencing revealed a heterozygous c. 335 G>A variation in the beaded filament structural protein 2(BFSP2) gene, which resulted in the replacement of a highly conserved glycine by glutamic at codon 112 (p. G112E). Haplotype analysis indicated that the affected members shared a common haplotype with markers near BFSP2. This mutation co-segregated with all affected individuals and was not observed in unaffected members or in 120 ethnically matched controls. Bioinformatic analyses confirmed that the mutation altered the hydrophobic and secondary structure of the protein around the substitution site. CONCLUSIONS We report a novel mutation (p.G112E) in the BFSP2 gene, underscoring the physiological importance of the beaded filament protein and supporting its role in human cataract formation.
Collapse
Affiliation(s)
- Qing Liu
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Lab , Beijing , China
| | | | | |
Collapse
|
31
|
Gai D, Nicholl J, Waters W, Barnett CP, Yu S. Interstitial deletion at chromosome 16p13.2 involving TMEM114 (transmembrane protein 114) in a boy and his father without cataract. Am J Med Genet A 2013; 164A:834-6. [PMID: 24357539 DOI: 10.1002/ajmg.a.36336] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Accepted: 09/29/2013] [Indexed: 11/08/2022]
Affiliation(s)
- Dayu Gai
- University of Melbourne, Melbourne, Victoria, Australia
| | | | | | | | | |
Collapse
|
32
|
Bennett TM, Maraini G, Jin C, Sun W, Hejtmancik JF, Shiels A. Noncoding variation of the gene for ferritin light chain in hereditary and age-related cataract. Mol Vis 2013; 19:835-44. [PMID: 23592921 PMCID: PMC3626299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Accepted: 04/09/2013] [Indexed: 10/27/2022] Open
Abstract
PURPOSE Cataract is a clinically and genetically heterogeneous disorder of the ocular lens and an important cause of visual impairment. The aim of this study was to map and identify the gene underlying autosomal dominant cataract segregating in a four-generation family, determine the lens expression profile of the identified gene, and test for its association with age-related cataract in a case-control cohort. METHODS Genomic DNA was prepared from blood leukocytes, and genotyping was performed by means of single-nucleotide polymorphism markers and microsatellite markers. Linkage analyses were performed using the GeneHunter and MLINK programs, and mutation detection was achieved by dideoxy cycle sequencing. Lens expression studies were performed using reverse-transcription polymerase chain reaction (RT-PCR) and in situ hybridization. RESULTS Genome-wide linkage analysis with single nucleotide polymorphism markers in the family identified a likely disease-haplotype interval on chromosome 19q (rs888861-[~17Mb]-rs8111640) that encompassed the microsatellite marker D19S879 (logarithm of the odds score [Z]=2.03, recombination distance [θ]=0). Mutation profiling of positional-candidate genes detected a heterozygous, noncoding G-to-T transversion (c.-168G>T) located in the iron response element (IRE) of the gene coding for ferritin light chain (FTL) that cosegregated with cataract in the family. Serum ferritin levels were found to be abnormally elevated (~fourfold), without evidence of iron overload, in an affected family member; this was consistent with a diagnosis of hereditary hyperferritinemia-cataract syndrome. No sequence variations located within the IRE were detected in a cohort of 197 cases with age-related cataract and 102 controls with clear lenses. Expression studies of human FTL, and its mouse counterpart FTL1, in the lens detected RT-PCR amplicons containing full-length protein-coding regions, and strong in situ localization of FTL1 transcripts to the lens equatorial epithelium and peripheral cortex. CONCLUSIONS The data are consistent with robust transcription of FTL in the lens, and suggest that whereas variations clustered in the IRE of the FTL gene are directly associated with hereditary hyperferritinemia-cataract syndrome, such IRE variations are unlikely to play a significant role in the genetic etiology of age-related cataract.
Collapse
Affiliation(s)
- Thomas M. Bennett
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO
| | | | - Chongfei Jin
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD
| | - Wenmin Sun
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD
| | - J. Fielding Hejtmancik
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD
| | - Alan Shiels
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO
| |
Collapse
|
33
|
Lachke SA, Ho JWK, Kryukov GV, O'Connell DJ, Aboukhalil A, Bulyk ML, Park PJ, Maas RL. iSyTE: integrated Systems Tool for Eye gene discovery. Invest Ophthalmol Vis Sci 2012; 53:1617-27. [PMID: 22323457 DOI: 10.1167/iovs.11-8839] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
PURPOSE To facilitate the identification of genes associated with cataract and other ocular defects, the authors developed and validated a computational tool termed iSyTE (integrated Systems Tool for Eye gene discovery; http://bioinformatics.udel.edu/Research/iSyTE). iSyTE uses a mouse embryonic lens gene expression data set as a bioinformatics filter to select candidate genes from human or mouse genomic regions implicated in disease and to prioritize them for further mutational and functional analyses. METHODS Microarray gene expression profiles were obtained for microdissected embryonic mouse lens at three key developmental time points in the transition from the embryonic day (E)10.5 stage of lens placode invagination to E12.5 lens primary fiber cell differentiation. Differentially regulated genes were identified by in silico comparison of lens gene expression profiles with those of whole embryo body (WB) lacking ocular tissue. RESULTS Gene set analysis demonstrated that this strategy effectively removes highly expressed but nonspecific housekeeping genes from lens tissue expression profiles, allowing identification of less highly expressed lens disease-associated genes. Among 24 previously mapped human genomic intervals containing genes associated with isolated congenital cataract, the mutant gene is ranked within the top two iSyTE-selected candidates in approximately 88% of cases. Finally, in situ hybridization confirmed lens expression of several novel iSyTE-identified genes. CONCLUSIONS iSyTE is a publicly available Web resource that can be used to prioritize candidate genes within mapped genomic intervals associated with congenital cataract for further investigation. Extension of this approach to other ocular tissue components will facilitate eye disease gene discovery.
Collapse
Affiliation(s)
- Salil A Lachke
- Division of Genetics, Department of Medicine, Brigham and Women’s Hospital, Harvard edical School, Boston, Massachusetts, USA
| | | | | | | | | | | | | | | |
Collapse
|
34
|
Lachke SA, Higgins AW, Inagaki M, Saadi I, Xi Q, Long M, Quade BJ, Talkowski ME, Gusella JF, Fujimoto A, Robinson ML, Yang Y, Duong QT, Shapira I, Motro B, Miyoshi J, Takai Y, Morton CC, Maas RL. The cell adhesion gene PVRL3 is associated with congenital ocular defects. Hum Genet 2012; 131:235-50. [PMID: 21769484 PMCID: PMC3279124 DOI: 10.1007/s00439-011-1064-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2011] [Accepted: 07/02/2011] [Indexed: 12/13/2022]
Abstract
We describe a male patient (patient DGAP113) with a balanced translocation, 46,XY,t(1;3)(q31.3;q13.13), severe bilateral congenital cataracts, CNS abnormalities and mild developmental delay. Fluorescence in situ hybridization (FISH) and suppression PCR demonstrated that the chromosome 3 breakpoint lies ~515 kb upstream of the PVRL3 gene, while the chromosome 1 breakpoint lies ~50 kb upstream of the NEK7 gene. Despite the fact that NEK7 is closer to a translocation breakpoint than PVRL3, NEK7 transcript levels are unaltered in patient DGAP113 lymphoblastoid cells and Nek7-deficient mice exhibit no detectable ocular phenotype. In contrast, the expression of PVRL3, which encodes the cell adhesion protein Nectin 3, is significantly reduced in patient DGAP113 lymphoblastoid cells, likely due to a position effect caused by the chromosomal translocation. Nectin 3 is expressed in the mouse embryonic ciliary body and lens. Moreover, Pvrl3 knockout mice as well as a spontaneous mouse mutant ari (anterior retinal inversion), that maps to the Pvrl3 locus, exhibit lens and other ocular defects involving the ciliary body. Collectively, these data identify PVRL3 as a critical gene involved in a Nectin-mediated cell-cell adhesion mechanism in human ocular development.
Collapse
Affiliation(s)
- Salil A. Lachke
- Division of Genetics, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115 USA
- Department of Biological Sciences, University of Delaware, Newark DE 19716 USA
| | - Anne W. Higgins
- Departments of Obstetrics, Gynecology and Reproductive Biology and of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115 USA
| | - Maiko Inagaki
- Radiation Research Center for Frontier Science Research, Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553 Japan
| | - Irfan Saadi
- Division of Genetics, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115 USA
| | - Qiongchao Xi
- Division of Genetics, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115 USA
| | - Michelle Long
- Departments of Obstetrics, Gynecology and Reproductive Biology and of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115 USA
| | - Bradley J. Quade
- Departments of Obstetrics, Gynecology and Reproductive Biology and of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115 USA
| | - Michael E. Talkowski
- Molecular Neurogenetics Unit, Center for Human Genetic Research, Massachusetts General Hospital and Department of Genetics, Harvard Medical School, Boston, MA 02114 USA
| | - James F. Gusella
- Molecular Neurogenetics Unit, Center for Human Genetic Research, Massachusetts General Hospital and Department of Genetics, Harvard Medical School, Boston, MA 02114 USA
| | - Atsuko Fujimoto
- Department of Pediatrics, Keck School of Medicine, University of Southern California Medical Center, Los Angeles, CA 90033 USA
| | | | - Ying Yang
- Center for Human and Molecular Genetics, Columbus Children’s Research Institute, Columbus, OH 43205 USA
| | - Quynh T. Duong
- The Ohio State University College of Optometry, Columbus, OH 43210 USA
| | - Irit Shapira
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900 Israel
| | - Benny Motro
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900 Israel
| | - Jun Miyoshi
- Department of Molecular Biology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka 537-8511 Japan
| | - Yoshimi Takai
- Division of Molecular and Cellular Biology, Kobe University Graduate School of Medicine, Kobe 650-0017 Japan
| | - Cynthia C. Morton
- Departments of Obstetrics, Gynecology and Reproductive Biology and of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115 USA
| | - Richard L. Maas
- Division of Genetics, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115 USA
| |
Collapse
|
35
|
Chograni M, Chaabouni M, Mâazoul F, Bouzid H, Kraiem A, Chaabouni HBB. Absence of mutations in four genes encoding for congenital cataract and expressed in the human brain in Tunisian families with cataract and mental retardation. BMC Ophthalmol 2011; 11:35. [PMID: 22103961 PMCID: PMC3258189 DOI: 10.1186/1471-2415-11-35] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Accepted: 11/21/2011] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND To identify the genetic defect associated with autosomal recessive congenital cataract (ARCC), mental retardation (MR) and ARCC, MR and microcephaly present in most patients in four Tunisian consanguineous families. METHODS We screened four genes implicated in congenital cataract by direct sequencing in two groups of patients; those affected by ARCC associated to MR and those who presented also microcephaly. Among its three genes PAX6, PITX3 and HSF4 are expressed in human brain and one gene LIM2 encodes for the protein MP20 that interact with the protein galectin-3 expressed in human brain and plays a crucial role in its development. All genes were screened by direct sequencing in two groups of patients; those affected by ARCC associated to MR and those who presented also microcephaly. RESULTS We report no mutation in the four genes of congenital cataract and its flanking regions. Only variations that did not segregate with the studied phenotypes (ARCC associated to MR, ARCC associated with MR and microcephaly) are reported. We detected three intronic variations in PAX6 gene: IVS4 -274insG (intron 4), IVS12 -174G>A (intron12) in the four studied families and IVS4 -195G>A (intron 4) in two families. Two substitutions polymorphisms in PITX3 gene: c.439 C>T (exon 3) and c.930 C>A (exon4) in one family. One intronic variation in HSF4 gene: IVS7 +93C>T (intron 7) identified in one family. And three intronic substitutions in LIM2 gene identified in all four studied families: IVS2 -24A>G (intron 2), IVS4 +32C>T (intron 4) and c.*15A>C (3'-downstream sequence). CONCLUSION Although the role of the four studied genes: PAX6, PITX3, HSF4 and LIM2 in both ocular and central nervous system development, we report the absence of mutations in all studied genes in four families with phenotypes associating cataract, MR and microcephaly.
Collapse
Affiliation(s)
- Manèl Chograni
- University Tunis Elmanar, Laboratoire Génétique Humaine, Tunis, Tunisia
| | | | | | | | | | | |
Collapse
|
36
|
Shi Y, De Maria AB, Wang H, Mathias RT, FitzGerald PG, Bassnett S. Further analysis of the lens phenotype in Lim2-deficient mice. Invest Ophthalmol Vis Sci 2011; 52:7332-9. [PMID: 21775657 DOI: 10.1167/iovs.11-7724] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Lim2 (MP20) is the second most abundant integral protein of lens fiber cell membranes. A comparative analysis was performed of wild-type and Lim2-deficient (Lim2(Gt/Gt)) mouse lenses, to better define the anatomic and physiologic roles of Lim2. METHODS Scanning electron microscopy (SEM) and confocal microscopy were used to assess the contribution of Lim2 to lens tissue architecture. Differentiation-dependent changes in cytoskeletal composition were identified by mass spectrometry and immunoblot analysis. The effects on cell-cell communication were quantified using impedance analysis. RESULTS Lim2-null lenses were grossly normal. At the cellular level, however, subtle structural alterations were evident. Confocal microscopy and SEM analysis revealed that cortical Lim2(Gt/Gt) fiber cells lacked the undulating morphology that characterized wild-type fiber cells. On SDS-PAGE analysis the composition of cortical fiber cells from wild-type and Lim2-null lenses appeared similar. However, marked disparities were evident in samples prepared from the lens core of the two genotypes. Several cytoskeletal proteins that were abundant in wild-type core fiber cells were diminished in the cores of Lim2(Gt/Gt) lenses. Electrophysiological measurements indicated a small decrease in the membrane potential of Lim2(Gt/Gt) lenses and a two-fold increase in the effective intracellular resistivity. In the lens core, this may have reflected decreased expression levels of the gap junction protein connexin 46 (Cx46). In contrast, increased resistivity in the outer cell layers of Lim2(Gt/Gt) lenses could not be attributed to decreased connexin expression and may reflect the absence of cell fusions in Lim2(Gt/Gt) lenses. CONCLUSIONS Comparative analysis of wild-type and Lim2-deficient lenses has implicated Lim2 in maintenance of cytoskeletal integrity, cell morphology, and intercellular communication.
Collapse
Affiliation(s)
- Yanrong Shi
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | | | | | | | | | | |
Collapse
|
37
|
Bennett TM, Shiels A. A recurrent missense mutation in GJA3 associated with autosomal dominant cataract linked to chromosome 13q. Mol Vis 2011; 17:2255-62. [PMID: 21897748 PMCID: PMC3164684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Accepted: 08/16/2011] [Indexed: 11/03/2022] Open
Abstract
PURPOSE To map and identify the genetic defect underlying autosomal dominant cataract segregating in a 5-generation Caucasian American family. METHODS Genomic DNA was prepared from blood leukocytes, genotyping was performed using microsatellite markers, and logarithm of the odds (LOD) scores were calculated using the LINKAGE programs. Mutation profiling was performed using direct exon cycle-sequencing and restriction fragment analysis. Protein function effects were evaluated using in silico prediction algorithms. RESULTS Significant evidence of linkage was obtained at marker D13S175 (maximum LOD score [Z(max)]=3.67; maximum recombination fraction [θ(max)]=0.04) and D13S1316 (Z(max)=2.80, θ(max)=0.0). Haplotyping indicated that the disease lay in the ~170 Kb physical interval between D13S1316 and D13S175, which contained the gene for gap-junction protein alpha-3 (GJA3) or connexin-46. Sequencing of GJA3 detected a heterozygous transition (c.130G>A) in exon-2 that resulted in gain of an Hsp92 II restriction site. Allele-specific PCR amplification and restriction analysis confirmed that the novel Hsp92 II site co-segregated with cataract in the family but was not detected in 192 normal unrelated individuals. The c.130G>A transition was predicted to result in a non-conservative substitution of valine-to-methionine at codon 44 (p.V44M) with damaging effects on protein function. CONCLUSIONS These data confirm GJA3 as one of the most frequently mutated genes that underlie autosomal dominant cataract in humans, and further emphasize the importance of connexin function in maintaining lens transparency.
Collapse
Affiliation(s)
- Thomas M. Bennett
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St Louis, MO
| | - Alan Shiels
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St Louis, MO
- Department of Genetics, Washington University School of Medicine, St Louis, MO
| |
Collapse
|
38
|
Churchill A, Graw J. Clinical and experimental advances in congenital and paediatric cataracts. Philos Trans R Soc Lond B Biol Sci 2011; 366:1234-49. [PMID: 21402583 DOI: 10.1098/rstb.2010.0227] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Cataracts (opacities of the lens) are frequent in the elderly, but rare in paediatric practice. Congenital cataracts (in industrialized countries) are mainly caused by mutations affecting lens development. Much of our knowledge about the underlying mechanisms of cataractogenesis has come from the genetic analysis of affected families: there are contributions from genes coding for transcription factors (such as FoxE3, Maf, Pitx3) and structural proteins such as crystallins or connexins. In addition, there are contributions from enzymes affecting sugar pathways (particularly the galactose pathway) and from a quite unexpected area: axon guidance molecules like ephrins and their receptors. Cataractous mouse lenses can be identified easily by visual inspection, and a remarkable number of mutant lines have now been characterized. Generally, most of the mouse mutants show a similar phenotype to their human counterparts; however, there are some remarkable differences. It should be noted that many mutations affect genes that are expressed not only in the lens, but also in tissues and organs outside the eye. There is increasing evidence for pleiotropic effects of these genes, and increasing consideration that cataracts may act as early and readily detectable biomarkers for a number of systemic syndromes.
Collapse
|
39
|
Chen J, Ma Z, Jiao X, Fariss R, Kantorow WL, Kantorow M, Pras E, Frydman M, Pras E, Riazuddin S, Riazuddin SA, Hejtmancik JF. Mutations in FYCO1 cause autosomal-recessive congenital cataracts. Am J Hum Genet 2011; 88:827-838. [PMID: 21636066 DOI: 10.1016/j.ajhg.2011.05.008] [Citation(s) in RCA: 125] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 04/29/2011] [Accepted: 05/09/2011] [Indexed: 12/20/2022] Open
Abstract
Congenital cataracts (CCs), responsible for about one-third of blindness in infants, are a major cause of vision loss in children worldwide. Autosomal-recessive congenital cataracts (arCC) form a clinically diverse and genetically heterogeneous group of disorders of the crystalline lens. To identify the genetic cause of arCC in consanguineous Pakistani families, we performed genome-wide linkage analysis and fine mapping and identified linkage to 3p21-p22 with a summed LOD score of 33.42. Mutations in the gene encoding FYVE and coiled-coil domain containing 1 (FYCO1), a PI(3)P-binding protein family member that is associated with the exterior of autophagosomes and mediates microtubule plus-end-directed vesicle transport, were identified in 12 Pakistani families and one Arab Israeli family in which arCC had previously been mapped to the overlapping CATC2 region. Nine different mutations were identified, including c.3755 delC (p.Ala1252AspfsX71), c.3858_3862dupGGAAT (p.Leu1288TrpfsX37), c.1045 C>T (p.Gln349X), c.2206C>T (p.Gln736X), c.2761C>T (p.Arg921X), c.2830C>T (p.Arg944X), c.3150+1 G>T, c.4127T>C (p.Leu1376Pro), and c.1546C>T (p.Gln516X). Fyco1 is expressed in the mouse embryonic and adult lens and peaks at P12d. Expressed mutant proteins p.Leu1288TrpfsX37 and p.Gln736X are truncated on immunoblots. Wild-type and p.L1376P FYCO1, the only missense mutant identified, migrate at the expected molecular mass. Both wild-type and p. Leu1376Pro FYCO1 proteins expressed in human lens epithelial cells partially colocalize to microtubules and are found adjacent to Golgi, but they primarily colocalize to autophagosomes. Thus, FYCO1 is involved in lens development and transparency in humans, and mutations in this gene are one of the most common causes of arCC in the Pakistani population.
Collapse
Affiliation(s)
- Jianjun Chen
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Zhiwei Ma
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Xiaodong Jiao
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Robert Fariss
- Imaging Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Wanda Lee Kantorow
- Department of Biomedical Science, Florida Atlantic University, room 207, Biomedical building, 777 Glades Rd. Boca Raton, FL, USA
| | - Marc Kantorow
- Department of Biomedical Science, Florida Atlantic University, room 207, Biomedical building, 777 Glades Rd. Boca Raton, FL, USA
| | - Eran Pras
- Department of Ophthalmology, Assaf Harofeh Medical Center, Zerifin, Israel; affiliated with the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Moshe Frydman
- The Danek Gertner Institute of Human Genetics, Sheba Medical Center, Ramat Gan, Israel; affiliated with the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Elon Pras
- The Danek Gertner Institute of Human Genetics, Sheba Medical Center, Ramat Gan, Israel; affiliated with the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Sheikh Riazuddin
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore 53700, Pakistan; Allama Iqbal Medical College, Lahore 54550, Pakistan
| | - S Amer Riazuddin
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore 53700, Pakistan; The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - J Fielding Hejtmancik
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| |
Collapse
|
40
|
Ding X, Wang B, Luo Y, Hu S, Zhou G, Zhou Z, Wang J, Ma X, Qi Y. A novel mutation in the connexin 46 (GJA3) gene associated with congenital cataract in a Chinese pedigree. Mol Vis 2011; 17:1343-9. [PMID: 21647269 PMCID: PMC3107996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Accepted: 05/13/2011] [Indexed: 10/26/2022] Open
Abstract
PURPOSE To identify the potential pathogenic mutation in a three-generation Chinese family with congenital nuclear pulverulent cataracts. METHODS A three-generation pedigree was recruited for our study. Three patients and four healthy members of the family underwent a comprehensive clinical examination. Genomic DNA extracted from peripheral blood was amplified using the polymerase chain reaction (PCR) method and the exons of all candidate genes were sequenced. RESULTS When sequencing the encoding regions of the candidate genes, a novel mutation (c.559C>T) was identified in the gap junction protein alpha 3 (GJA3) gene, which resulted in the substitution of highly conserved proline by serine at codon 187 (P187S). There was no noticeable nucleotide polymorphism in other candidate genes. The mutation co-segregated with all patients, but was absent in the healthy members and 100 normal individuals. CONCLUSIONS The present study identified a novel mutation (c.559C>T) in the GJA3 gene associated with autosomal dominant pulverulent cataracts in a Chinese family. As the first report to relate p.P187S mutation in GJA3, it expands the mutation spectrum of GJA3 in association with congenital cataracts.
Collapse
Affiliation(s)
- Xuchen Ding
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Binbin Wang
- Department of Genetics, National Research Institute for Family Planning, Beijing, China
| | - Yongfeng Luo
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Shanshan Hu
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Guangkai Zhou
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Zhou Zhou
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Jing Wang
- Department of Genetics, National Research Institute for Family Planning, Beijing, China
| | - Xu Ma
- Department of Genetics, National Research Institute for Family Planning, Beijing, China
| | - Yanhua Qi
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| |
Collapse
|
41
|
Puk O, Ahmad N, Wagner S, Hrabé de Angelis M, Graw J. Microphakia and congenital cataract formation in a novel Lim2(C51R) mutant mouse. Mol Vis 2011; 17:1164-71. [PMID: 21617753 PMCID: PMC3102026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Accepted: 04/28/2011] [Indexed: 10/31/2022] Open
Abstract
PURPOSE Within a mutagenesis screen, we identified the new mouse mutant Aca47 with small lenses and reduced axial eye lengths. The aim of the actual study was the molecular and morphological characterization of the mouse mutant Aca47. METHODS We analyzed the offspring of paternally N-ethyl-N-nitrosourea (ENU) treated C57BL/6J mice for eye-size parameters by non-invasive in vivo laser interference biometry. Linkage analysis of the eye size mutant Aca47 was performed using single nucleotide polymorphisms and microsatellite markers. The Aca47 mutation was identified by sequence analysis of positional candidate genes. A general polymorphism at the mutated site was excluded by restriction analysis. Eyes of the Aca47 mouse mutant were characterized by histology. Visual properties were examined in the virtual drum. RESULTS We identified a new mutant characterized by a significantly smaller lens and reduced axial eye length without any changes for cornea thickness, anterior chamber depth or aqueous humor size. The smaller size of lens was more pronounced in the homozygous mutants, which further developed congenital cataracts in the lens nucleus. The mutation was mapped to chromosome 7 between the markers D7Mit247 and D7Mit81. Using a positional candidate approach, the lens intrinsic integral membrane protein MP19 encoding gene Lim2 was sequenced; a T → C exchange at cDNA position 151 leads to a cysteine-to-arginine substitution at position 51 of the Lim2 protein. Eye histology of adult heterozygous mutants did not show alterations on the cellular level. However, homozygous lenses revealed irregularly arranged lens fiber layers in the cortex. Virtual vision tests indicated that visual properties are not affected by reduced eye size of heterozygous individuals. CONCLUSIONS These findings demonstrate a novel missense mutation in the Lim2 gene that affects lens development in a semidominant manner. Since homozygous mutants develop congenital lens opacities, this line can be used as a model for inherited cataract formation in humans.
Collapse
Affiliation(s)
- Oliver Puk
- Helmholtz Center Munich, German Research Center for Environmental Health, Institutes of Developmental Genetics, Neuherberg, Germany
| | - Nafees Ahmad
- Helmholtz Center Munich, German Research Center for Environmental Health, Institutes of Developmental Genetics, Neuherberg, Germany
| | - Sibylle Wagner
- Helmholtz Center Munich, German Research Center for Environmental Health, Institutes of Experimental Genetics, Neuherberg, Germany
| | - Martin Hrabé de Angelis
- Helmholtz Center Munich, German Research Center for Environmental Health, Institutes of Experimental Genetics, Neuherberg, Germany,Chair of Experimental Genetics, Technical University Munich, Center of Life and Food Sciences, Freising-Weihenstephan, Germany
| | - Jochen Graw
- Helmholtz Center Munich, German Research Center for Environmental Health, Institutes of Developmental Genetics, Neuherberg, Germany
| |
Collapse
|
42
|
Kumar M, Agarwal T, Khokhar S, Kumar M, Kaur P, Roy TS, Dada R. Mutation screening and genotype phenotype correlation of α-crystallin, γ-crystallin and GJA8 gene in congenital cataract. Mol Vis 2011; 17:693-707. [PMID: 21423869 PMCID: PMC3060158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2010] [Accepted: 03/07/2011] [Indexed: 11/29/2022] Open
Abstract
PURPOSE To screen α-crystallin (CRYAB), γ-crystallin (CRYGC and CRYGD), and Connexin 50 (Cx-50 or GJA8) genes in congenital cataract patients and controls. METHODS Thirty clinically diagnosed congenital cataract cases below 3 years of age from northern India, presenting at Dr. R. P. Centre for Ophthalmic Sciences (AIIMS, New Delhi, India) were enrolled in this study. Genomic DNA was extracted from peripheral blood, all coding and exon/intron regions were amplified using PCR and direct sequencing was performed to detect any nucleotide variation. ProtScale and Discovery Studio programs were used for insilico and structural analysis of non-synonymous mutations. RESULTS DNA sequencing analysis of CRYAB, CRYGC, CRYGD, and GJA8 showed a total of six variations of which two were novel (CRYGC:p.R48H and GJA8:p.L281C) and four have been previously reported (CRYAB: rs11603779T>G, GJA8: p.L268L, CRYGD: p.R95R, and c.T564C). Both the novel changes, in CRYGC and GJA8 were found in 16.6% of the patients. Previously reported nucleotide alterations (CRYGD:p.R95R and c.T564C) were found in 90% of the patients. Insilico and structural analysis data suggested that two novel non-synonymous mutations altered the stability and solvent accessibility of γC-crystallin and Cx-50 proteins which may lead to lens opacification. CONCLUSIONS We observed two novel nonsynonymous variations and four reported variations in CRYAB, CRYGC, CRYGD, and GJA8. The p.R48H variation in γC-crystallin may disrupt the normal structure of lens and can cause cataract. Cx50 is responsible for joining the lens cells into a functional syncytium and a mutation (p.L281C) in GJA8 may lead to lens opacification resulting in cataract formation. This study further expands the mutation spectrum of congenital cataract and help understanding how mutant proteins lead to opacification of lens.
Collapse
Affiliation(s)
- Manoj Kumar
- Laboratory for Molecular Reproduction and Genetics, Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India
| | - Tushar Agarwal
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Sudarshan Khokhar
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Manoj Kumar
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India
| | - Punit Kaur
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India
| | - Tara Sankar Roy
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India
| | - Rima Dada
- Laboratory for Molecular Reproduction and Genetics, Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India
| |
Collapse
|
43
|
Zhao R, Yang Y, He X, Liu Z, Wang P, Zhou L, Tang J, Xu W, Li L, Zhu Y. An autosomal dominant cataract locus mapped to 19q13-qter in a Chinese family. Mol Vis 2011; 17:265-9. [PMID: 21283564 PMCID: PMC3030603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2010] [Accepted: 01/19/2011] [Indexed: 10/24/2022] Open
Abstract
PURPOSE The aim of this study was to map the disease locus of autosomal dominant cataracts (ADC) in a Chinese family. METHODS A four-generation family with multiple individuals affected by ADC was investigated. Genomic DNA was collected from 22 family members. A gene-scan at known candidate ADC loci was performed. To achieve fine-mapping we genotyped fourteen STR markers at the critical region of 19q. The two-point logarithm of odds (LOD) score was calculated using Linkage Software Package Version 5.1 for linkage analysis. The haplotype was constructed using Cyrillic software. RESULTS Ten members of this Chinese family were affected by nuclear cataracts. Initially, linkage analysis revealed a significant LOD score of 3.82 at the STR marker D19S418. Subsequently, after refine-marker analysis, a maximum LOD score (Z(max)=4.25) was obtained at the D19S877 (θ=0). Haplotype analysis also confirmed the locus and further narrowed it down to a critical interval from the marker D19S924 to the 19qter. CONCLUSIONS We have successfully mapped an ADC locus to 19q13-qter. Previous studies have identified three cataract loci on 19q; however, we found no overlap between the locus of this study and any of the previously identified loci. We therefore suggest that the 19q13-qter locus in this family is a new locus for ADC.
Collapse
Affiliation(s)
- Rui Zhao
- The Laboratory of Genetics And Metabolism, Hunan Children’s Research Institute, Hunan Children’s Hospital, University of South China, Changsha, China
| | - Yonjia Yang
- The Laboratory of Genetics And Metabolism, Hunan Children’s Research Institute, Hunan Children’s Hospital, University of South China, Changsha, China
| | - Xinyu He
- The Laboratory of Genetics And Metabolism, Hunan Children’s Research Institute, Hunan Children’s Hospital, University of South China, Changsha, China
| | - Zheng Liu
- School of Biology, Georgia Institute of Technology, Atlanta, GA
| | - Pin Wang
- Department Of Ophtalmology, Hunan Children’s Hospital, University of South China, Changsha, China
| | - Lijun Zhou
- Department Of Ophtalmology, Hunan Children’s Hospital, University of South China, Changsha, China
| | - Jinsong Tang
- Institute of Mental Health,The Second Xiangya Hospital, Central South University, Changsha, China
| | - Wei Xu
- The First Hospital of Hunan Province, Changsha, China
| | - Liping Li
- The Laboratory of Basic Medicine, Hunan Children’s Research Institute, Hunan Children’s Hospital, University of South China, Changsha, China
| | - Yimin Zhu
- The Laboratory of Genetics And Metabolism, Hunan Children’s Research Institute, Hunan Children’s Hospital, University of South China, Changsha, China,Department of Emergency, Hunan Children’s Hospital, University of South China,Changsha, China
| |
Collapse
|
44
|
Mapping of a novel locus associated with autosomal recessive congenital cataract to chromosome 8p. Mol Vis 2010; 16:2911-5. [PMID: 21203409 PMCID: PMC3013063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2010] [Accepted: 12/17/2010] [Indexed: 11/15/2022] Open
Abstract
PURPOSE To identify the disease locus for autosomal recessive congenital cataracts in a consanguineous Pakistani family. METHODS All affected individuals underwent a detailed ophthalmologic examination. Blood samples were collected and genomic DNA was extracted. A genome-wide scan was completed with fluorescently-labeled microsatellite markers on genomic DNA from affected and unaffected family members. Logarithms of odds (LOD) scores were calculated under a fully penetrant autosomal recessive model of inheritance. RESULTS Ophthalmic examination suggested that affected individuals have bilateral cataracts. Linkage analysis localized the critical interval to chromosome 8p with LOD scores of 3.19, and 3.08 at θ=0, obtained with markers D8S549 and D8S550, respectively. Haplotype analyses refined the critical interval to 37.92 cM (16.28 Mb) region, flanked by markers, D8S277 proximally and D8S1734 distally. CONCLUSIONS Here, we report a new locus for autosomal recessive congenital cataract mapped to chromosome 8p in a consanguineous Pakistani family.
Collapse
|
45
|
Molecular genetic analysis of autosomal dominant late-onset cataract in a Chinese Family. ACTA ACUST UNITED AC 2010; 30:792-7. [PMID: 21181374 DOI: 10.1007/s11596-010-0660-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Indexed: 10/18/2022]
Abstract
Congenital cataract is a highly heterogeneous disorder at both the genetic and the clinical-phenotypic levels. A unique cataract was observed in a 4-generation Chinese family, which was characterized by autosomal dominant inheritance and late-onset. Mutations in the 13 known genes (CRYAA, CRYAB, CRYBB1, CRYBB2, CRYGC, CRYBA1/A3, CRYGD, Connexin50, Connexin46, intrinsic membrane protein LIM2, cytoskeletal protein BFSP2, the major intrinsic protein-MIP and the heat shock factor HSF4) have previously been demonstrated to be the frequent reason for isolated congenital cataracts, but the exact molecular basis and underlying mechanisms of congenital cataract still remain unclear. This study was designed to find whether these 13 genes developed any mutation in the family members and to identify the disease-causing gene. Polymerase chain reaction (PCR) and direct DNA sequence analysis were carried out to detect the 13 genes. The results showed that no mutation causing amino acid alternations was found in these potential candidate genes among all patients in the family, and only several single-nucleotide polymorphisms (SNPs) were identified. A transitional mutation in the fourth intron of CRYBB2 and some silent mutations in the first exon of BFSP2 and CRYGD were found in the cataract family, but further study showed that these mutations could also be found in normal controls. It was concluded that some unidentified genes may underlie the occurrence of late-onset cataract in this family. A genome-wide screening will be carried out in the next study.
Collapse
|
46
|
Sabir N, Riazuddin SA, Butt T, Iqbal F, Nasir IA, Zafar AU, Qazi ZA, Butt NH, Khan SN, Husnain T, Hejtmancik JF, Riazuddin S. Mapping of a new locus associated with autosomal recessive congenital cataract to chromosome 3q. Mol Vis 2010; 16:2634-8. [PMID: 21179239 PMCID: PMC3002966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2010] [Accepted: 12/03/2010] [Indexed: 12/03/2022] Open
Abstract
PURPOSE To localize the disease interval for autosomal recessive congenital cataracts in a consanguineous Pakistani family. METHODS All affected individuals underwent detailed ophthalmologic examination. Blood samples were collected and genomic DNA was extracted. A genome-wide scan was performed with fluorescently-labeled microsatellite markers on genomic DNA from affected and unaffected family members and logarithm of odds (LOD) scores were calculated. RESULTS Clinical records and ophthalmological examinations suggested that affected individuals have bilateral congenital cataracts. Genome-wide linkage analysis localized the critical interval to chromosome 3q with a maximum LOD score of 3.87 at θ=0; with marker D3S3609. Haplotype analyses refined the critical interval to a 23.39 cM (18.01 Mb) interval on chromosome 3q, flanked by D3S1614 proximally and D3S1262, distally. CONCLUSIONS Here, we report a new locus for autosomal recessive congenital cataract localized to chromosome 3q in a consanguineous Pakistani family.
Collapse
Affiliation(s)
- Namerah Sabir
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - S. Amer Riazuddin
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan,The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Tariq Butt
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Farheena Iqbal
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Idrees A. Nasir
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Ahmad U. Zafar
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | | | - Nadeem H. Butt
- Allama Iqbal Medical College, University of Health Sciences, Lahore, Pakistan
| | - Shaheen N. Khan
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Tayyab Husnain
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - J. Fielding Hejtmancik
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD
| | - Sheikh Riazuddin
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan,Allama Iqbal Medical College, University of Health Sciences, Lahore, Pakistan
| |
Collapse
|
47
|
Zhou G, Zhou N, Hu S, Zhao L, Zhang C, Qi Y. A missense mutation in CRYBA4 associated with congenital cataract and microcornea. Mol Vis 2010; 16:1019-24. [PMID: 20577656 PMCID: PMC2890555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2010] [Accepted: 06/01/2010] [Indexed: 11/12/2022] Open
Abstract
PURPOSE To identify mutations in a Chinese family with congenital cataract and microcornea. METHODS Detailed family history and clinical data were recorded. Genomic DNA was extracted from leukocytes of venous blood of the patients and noncarriers in this family along with 100 normal individuals. All six exons of crystallin, beta A4 gene (CRYBA4) were amplified by PCR methods and direct sequencing. RESULTS We identified a c.225G>T sequence change that led to an amino acid substitution G64W in the CRYBA4-induced protein in two patients of this family; this nucleotide substitution was not detected in the other individuals. CONCLUSIONS A novel missense mutation in CRYBA4 was identified in our study. It expands the mutation spectrum of CRYBA4 and provides useful information to the study of molecular pathogenesis of cataract and microcornea.
Collapse
|
48
|
Zhou Z, Hu S, Wang B, Zhou N, Zhou S, Ma X, Qi Y. Mutation analysis of congenital cataract in a Chinese family identified a novel missense mutation in the connexin 46 gene (GJA3). Mol Vis 2010; 16:713-9. [PMID: 20431721 PMCID: PMC2861125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Accepted: 04/15/2010] [Indexed: 11/03/2022] Open
Abstract
PURPOSE To identify the genetic defects in a three-generation Chinese family with congenital nuclear cataract. METHODS Four patients and three healthy members from the family underwent complete physical and ophthalmic examinations. Genomic DNA was extracted from peripheral blood leukocytes of the family members as well as from 100 healthy normal controls. Polymerase chain reaction (PCR) amplification and direct sequencing of all coding exons of candidate genes were performed. The functional consequences of the mutation were analyzed with biology softwares. RESULTS A novel mutation (c.130G>A) was identified in the connexin 46 gene (GJA3), which resulted in the substitution of valine by methionine at the highly conserved codon 44 of connexin 46. This mutation co-segregated among the affected members of the family and was not observed in either unaffected members or the 100 normal controls. CONCLUSIONS This is a novel missense mutation identified in the first extracellular loop of connexin 46; this expands the mutation spectrum of GJA3 in association with congenital cataract.
Collapse
Affiliation(s)
- Zhou Zhou
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Shanshan Hu
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Binbin Wang
- Department of Genetics, National Research Institute for Family Planning, Beijing, China
| | - Nan Zhou
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Shiyi Zhou
- Department of Genetics, National Research Institute for Family Planning, Beijing, China
| | - Xu Ma
- Department of Genetics, National Research Institute for Family Planning, Beijing, China
| | - Yanhua Qi
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| |
Collapse
|
49
|
Bchetnia M, Merdassi A, Charfeddine C, Mgaieth F, Kassar S, Ouechtati F, Chouchene I, Boussen H, Mokni M, Osman ADB, Boubaker MS, Abdelhak S, Elmatri L. Coexistence of mal de Meleda and congenital cataract in a consanguineous Tunisian family: two case reports. J Med Case Rep 2010; 4:108. [PMID: 20406438 PMCID: PMC2874570 DOI: 10.1186/1752-1947-4-108] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2009] [Accepted: 04/20/2010] [Indexed: 11/10/2022] Open
Abstract
Introduction Mal de Meleda is a rare form of palmoplantar keratoderma, with autosomal recessive transmission. It is characterized by diffuse erythema and hyperkeratosis of the palms and soles. Recently, mutations in the ARS (component B) gene (ARS, MIM: 606119) on chromosome 8q24.3 have been identified in families with this disorder. Congenital cataract is a visual disease that may interfere with sharp imaging of the retina. Mutations in the heat-shock transcription factor 4 gene (HSF4; MIM: 602438) may result in both autosomal dominant and autosomal recessive congenital cataracts. Case presentation A Tunisian family with two female siblings aged 45 and 30 years, presented with a clinical association of mal de Meleda and congenital cataract. The two patients exhibited diffuse palmoplantar keratodermas. One of them presented with a total posterior subcapsular cataract and had a best corrected visual acuity at 1/20 in the left eye and with the right eye was only able to count fingers at a distance of one foot. The other woman had a slight posterior subcapsular lenticular opacity and her best corrected visual acuity was 8/10 in the right eye and with her left eye she was only able to count fingers at a distance of one foot. A mutational analysis of their ARS gene revealed the presence of the homozygous missense mutation C99Y and two single nucleotide polymorphisms (-55G>C and -60G>C). The splice mutation (c.1327+4A-G) within intron 12 of the HSF4 gene, which has been previously described in Tunisian families with congenital cataract, was not found in the two probands within this family. Conclusion To the best of our knowledge, such original clinical association has not been reported previously. The association of these two autosomal recessive diseases might have occurred in this family due to a high degree of inbreeding. The C99Y mutation may be specific to the Tunisian population as it has been exclusively reported so far in only three Tunisian families with mal de Meleda.
Collapse
Affiliation(s)
- Mbarka Bchetnia
- Molecular Investigation of Genetic Orphan Diseases Research Unit, Institut Pasteur de Tunis, Tunis, Tunisia.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Yasmeen A, Riazuddin SA, Kaul H, Mohsin S, Khan M, Qazi ZA, Nasir IA, Zafar AU, Khan SN, Husnain T, Akram J, Hejtmancik JF, Riazuddin S. Autosomal recessive congenital cataract in consanguineous Pakistani families is associated with mutations in GALK1. Mol Vis 2010; 16:682-8. [PMID: 20405025 PMCID: PMC2855732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2009] [Accepted: 04/09/2010] [Indexed: 11/21/2022] Open
Abstract
PURPOSE To identify the pathogenic mutations responsible for autosomal recessive congenital cataracts in consanguineous Pakistani families. METHODS All affected individuals underwent detailed ophthalmologic and medical examination. Blood samples were collected and genomic DNA was extracted. A genome-wide scan was performed with polymorphic microsatellite markers on genomic DNA from affected and unaffected family members and logarithm of odds (LOD) scores were calculated. All coding exons of galactokinase (GALK1) were sequenced to identify pathogenic lesions. RESULTS Clinical records and ophthalmological examinations suggested that affected individuals have nuclear cataracts. Linkage analysis localized the critical interval to chromosome 17q with a maximum LOD score of 5.54 at theta=0, with D17S785 in family PKCC030. Sequencing of GALK1, a gene present in the critical interval, identified a single base pair deletion: c.410delG, which results in a frame shift leading to a premature termination of GALK1: p.G137fsX27. Additionally, we identified a missense mutation: c.416T>C, in family PKCC055 that results in substitution of a leucine residue at position 139 with a proline residue: p.L139P, and is predicted to be deleterious to the native GALK1 structure. CONCLUSIONS Here, we report pathogenic mutations in GALK1 that are responsible for autosomal recessive congenital cataracts in consanguineous Pakistani families.
Collapse
Affiliation(s)
- Afshan Yasmeen
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - S. Amer Riazuddin
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Haiba Kaul
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Sadia Mohsin
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Mohsin Khan
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | | | - Idrees A. Nasir
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Ahmad U. Zafar
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Shaheen N. Khan
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Tayyab Husnain
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Javed Akram
- Allama Iqbal Medical College, University of Health Sciences, Lahore, Pakistan
| | - J. Fielding Hejtmancik
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD
| | - Sheikh Riazuddin
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan,Allama Iqbal Medical College, University of Health Sciences, Lahore, Pakistan
| |
Collapse
|