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ABSTRACT: Hyaluronan (HA) plays a significant role in maintaining aqueous humor outflow in trabecular meshwork, the primary ocular tissue involved in glaucoma. We examined potential association of the single nucleotide polymorphisms (SNPs) of the HA synthesizing gene - hyaluronan synthase 2 (HAS2), hyaluronan binding protein 1 (HABP1) and HA catabolic gene hyaluronidase 3 (HYAL3) in the primary open angle glaucoma (POAG) patients in the Indian population. Thirteen tagged SNPs (6 for HAS2, 3 for HABP1 and 4 for HYAL3) were genotyped in 116 high tension (HTG), 321 non-high tension glaucoma (NHTG) samples and 96 unrelated, age-matched, glaucoma-negative, control samples. Allelic and genotypic association were analyzed by PLINK v1.04; haplotypes were identified using PHASE v2.1 and gene-gene interaction was analyzed using multifactor dimensionality reduction (MDR) v2.0. An allelic association (rs6651224; p= 0.03; OR: 0.49; 95% CI: 0.25-0.94) was observed at the second intron (C>G) of HAS2 both for NHTG and HTG. rs1057308 revealed a genotypic association (p=0.03) at the 5' UTR of HAS2 with only HTG. TCT haplotype (rs1805429 - rs2472614 - rs8072363) in HABP1 and TTAG and TTGA (rs2285044 - rs3774753 - rs1310073 - rs1076872) in HYAL3 were found to be significantly high (p< 0.05) both for HTG and NHTG compared to controls. Gene-gene interaction revealed HABP1 predominantly interacts with HAS2 in HTG while it associates with both HYAL3 and HAS2 in NHTG. This is the first genetic evidence, albeit from a smaller study, that the natural polymorphisms in the genes involved in hyaluronan metabolism are potentially involved in glaucomatous neurodegeneration.
Disease markers 08/2012; 33(3):145-54. · 1.64 Impact Factor
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ABSTRACT: Leucine rich repeat kinase 2 (LRRK2) gene defects cause Parkinson's disease (PD). Recently, LRRK2 has also been shown by genome wide association (GWA) studies to be a susceptibility gene for the disease. In India mutations in LRRK2 is a rare cause of PD. We, therefore, genotyped 64 SNPs across LRRK2 in 161 control samples and finally studied 6 haplotype tagging SNPs for association-based study on 300 cases and 446 ethnically matched controls to explore the potential role of LRRK2 as a susceptibility gene in PD for East Indians. We did not find any significant allele/ genotype or haplotype associations with PD suggesting that common genetic variants within LRRK2 play limited role in modulating PD among East Indians. In addition, we also screened for the common mutations (viz. p.R1441C, p.R1441G, p.R1441H, p.Y1699C, p.G2019S), and a risk variant common among Asians (p.G2385R) but did not observe any of the above mentioned variants in our cohort. Our study, therefore, strongly suggests that LRRK2 has minimal role as a candidate and susceptibility gene in PD pathogenesis among East Indians.
Disease markers 01/2012; 32(6):355-62. · 1.64 Impact Factor
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Arijit Mukhopadhyay,
Jamie M Kramer,
Gerard Merkx,
Dorien Lugtenberg,
Dominique F Smeets,
Merel A W Oortveld,
Ellen A W Blokland,
Jyoti Agrawal,
Annette Schenck,
Hans van Bokhoven,
Erik Huys,
Eric F Schoenmakers,
Ad Geurts van Kessel,
C Erik van Nouhuys,
Frans P M Cremers
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ABSTRACT: Microcephaly, mental retardation and congenital retinal folds along with other systemic features have previously been reported as a separate clinical entity. The sporadic nature of the syndrome and lack of clear inheritance patterns pointed to a genetic heterogeneity. Here, we report a genetic analysis of a female patient with microcephaly, congenital bilateral falciform retinal folds, nystagmus, and mental retardation. Karyotyping revealed a de novo pericentric inversion in chromosome 6 with breakpoints in 6p12.1 and 6q21. Fluorescence in situ hybridization analysis narrowed down the region around the breakpoints, and the breakpoint at 6q21 was found to disrupt the CDK19 gene. CDK19 was found to be expressed in a diverse range of tissues including fetal eye and fetal brain. Quantitative PCR of the CDK19 transcript from Epstein-Barr virus-transformed lymphoblastoid cell lines of the patient revealed ~50% reduction in the transcript (p = 0.02), suggesting haploinsufficiency of the gene. cdk8, the closest orthologue of human CDK19 in Drosophila has been shown to play a major role in eye development. Conditional knock-down of Drosophila cdk8 in multiple dendrite (md) neurons resulted in 35% reduced dendritic branching and altered morphology of the dendritic arbour, which appeared to be due in part to a loss of small higher order branches. In addition, Cdk8 mutant md neurons showed diminished dendritic fields revealing an important role of the CDK19 orthologue in the developing nervous system of Drosophila. This is the first time the CDK19 gene, a component of the mediator co-activator complex, has been linked to a human disease.
Human Genetics 09/2010; 128(3):281-91. · 5.07 Impact Factor
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Konstantinos Nikopoulos,
Hanka Venselaar,
Rob W.J. Collin,
Rosa Riveiro-Alvarez,
F. Nienke Boonstra,
Johanna M.M. Hooymans, Arijit Mukhopadhyay,
Deborah Shears,
Marleen van Bers,
Ilse J. de Wijs,
Anthonie J. van Essen,
Rolf H. Sijmons,
Mauk A.D. Tilanus,
C. Erik van Nouhuys,
Carmen Ayuso,
Lies H. Hoefsloot,
Frans P.M. Cremers
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ABSTRACT: Wnt signaling is a crucial component of the cell machinery orchestrating a series of physiological processes such as cell survival, proliferation, and migration. Among the plethora of roles that Wnt signaling plays, its canonical branch regulates eye organogenesis and angiogenesis. Mutations in the genes encoding the low density lipoprotein receptor protein 5 (LRP5) and frizzled 4 (FZD4), acting as coreceptors for Wnt ligands, cause familial exudative vitreoretinopathy (FEVR). Moreover, mutations in the gene encoding NDP, a ligand for these Wnt receptors, cause Norrie disease and FEVR. Both FEVR and Norrie disease share similar phenotypic characteristics, including abnormal vascularization of the peripheral retina and formation of fibrovascular masses in the eye that can lead to blindness. In this mutation update, we report 21 novel variants for FZD4, LRP5, and NDP, and discuss the putative functional consequences of missense mutations. In addition, we provide a comprehensive overview of all previously published variants in the aforementioned genes and summarize the phenotypic characteristics in mouse models carrying mutations in the orthologous genes. The increasing molecular understanding of Wnt signaling, related to ocular development and blood supply, offers more tools for accurate disease diagnosis that may be important in the development of therapeutic interventions. Hum Mutat 31:656–666, 2010. © 2010 Wiley-Liss, Inc.
Human Mutation 05/2010; 31(6):656 - 666. · 5.69 Impact Factor
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Konstantinos Nikopoulos,
Hanka Venselaar,
Rob W J Collin,
Rosa Riveiro-Alvarez,
F Nienke Boonstra,
Johanna M M Hooymans, Arijit Mukhopadhyay,
Deborah Shears,
Marleen van Bers,
Ilse J de Wijs,
Anthonie J van Essen,
Rolf H Sijmons,
Mauk A D Tilanus,
C Erik van Nouhuys,
Carmen Ayuso,
Lies H Hoefsloot,
Frans P M Cremers
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ABSTRACT: Wnt signaling is a crucial component of the cell machinery orchestrating a series of physiological processes such as cell survival, proliferation, and migration. Among the plethora of roles that Wnt signaling plays, its canonical branch regulates eye organogenesis and angiogenesis. Mutations in the genes encoding the low density lipoprotein receptor protein 5 (LRP5) and frizzled 4 (FZD4), acting as coreceptors for Wnt ligands, cause familial exudative vitreoretinopathy (FEVR). Moreover, mutations in the gene encoding NDP, a ligand for these Wnt receptors, cause Norrie disease and FEVR. Both FEVR and Norrie disease share similar phenotypic characteristics, including abnormal vascularization of the peripheral retina and formation of fibrovascular masses in the eye that can lead to blindness. In this mutation update, we report 21 novel variants for FZD4, LRP5, and NDP, and discuss the putative functional consequences of missense mutations. In addition, we provide a comprehensive overview of all previously published variants in the aforementioned genes and summarize the phenotypic characteristics in mouse models carrying mutations in the orthologous genes. The increasing molecular understanding of Wnt signaling, related to ocular development and blood supply, offers more tools for accurate disease diagnosis that may be important in the development of therapeutic interventions.
Human Mutation 03/2010; 31(6):656-66. · 5.69 Impact Factor
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Konstantinos Nikopoulos,
Christian Gilissen,
Alexander Hoischen,
C Erik van Nouhuys,
F Nienke Boonstra,
Ellen A W Blokland,
Peer Arts,
Nienke Wieskamp,
Tim M Strom,
Carmen Ayuso,
Mauk A D Tilanus,
Sanne Bouwhuis, Arijit Mukhopadhyay,
Hans Scheffer,
Lies H Hoefsloot,
Joris A Veltman,
Frans P M Cremers,
Rob W J Collin
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ABSTRACT: Familial exudative vitreoretinopathy (FEVR) is a genetically heterogeneous retinal disorder characterized by abnormal vascularisation of the peripheral retina, often accompanied by retinal detachment. To date, mutations in three genes (FZD4, LRP5, and NDP) have been shown to be causative for FEVR. In two large Dutch pedigrees segregating autosomal-dominant FEVR, genome-wide SNP analysis identified an FEVR locus of approximately 40 Mb on chromosome 7. Microsatellite marker analysis suggested similar at risk haplotypes in patients of both families. To identify the causative gene, we applied next-generation sequencing in the proband of one of the families, by analyzing all exons and intron-exon boundaries of 338 genes, in addition to microRNAs, noncoding RNAs, and other highly conserved genomic regions in the 40 Mb linkage interval. After detailed bioinformatic analysis of the sequence data, prioritization of all detected sequence variants led to three candidates to be considered as the causative genetic defect in this family. One of these variants was an alanine-to-proline substitution in the transmembrane 4 superfamily member 12 protein, encoded by TSPAN12. This protein has very recently been implicated in regulating the development of retinal vasculature, together with the proteins encoded by FZD4, LRP5, and NDP. Sequence analysis of TSPAN12 revealed two mutations segregating in five of 11 FEVR families, indicating that mutations in TSPAN12 are a relatively frequent cause of FEVR. Furthermore, we demonstrate the power of targeted next-generation sequencing technology to identify disease genes in linkage intervals.
The American Journal of Human Genetics 02/2010; 86(2):240-7. · 10.60 Impact Factor
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ABSTRACT: To describe the clinical phenotype in a family with primary open angle glaucoma harboring a p.Gln368X mutation in MYOC.
We identified a proband with primary open angle glaucoma and the p.Gln368X MYOC mutation. She and her six siblings were examined clinically, including Heidelberg Retina Tomography II, and venous blood samples were screened for other variants in MYOC, WDR36, OPTN, and CYP1B1.
Four individuals showed the p.Gln368X MYOC mutation, no other genetic variations were assessed. Two of these four siblings had glaucomatous optic disc changes with corresponding visual field losses and abnormal Heidelberg Retina Tomography results by the Moorfields regression analysis, one had abnormal results by the Moorfields regression analysis but no visual field loss, and one showed no glaucomatous signs or symptoms at all. These findings did not correlate with the age of the affected individuals.
In the primary open angle glaucoma family described here, we documented a wide range in clinical symptoms, demonstrating a highly variable penetrance of the MYOC p.Gln368X mutation.
Current eye research 01/2010; 35(1):31-6. · 1.51 Impact Factor
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F Nienke Boonstra,
C Erik van Nouhuys,
José Schuil,
Ilse J de Wijs,
Kim P van der Donk,
Kostas Nikopoulos, Arijit Mukhopadhyay,
Hans Scheffer,
Mauk A D Tilanus,
Frans P M Cremers,
Lies H Hoefsloot
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ABSTRACT: To describe the ophthalmic characteristics and to identify the molecular cause of FEVR in a cohort of Dutch probands and their family members.
Twenty families with familial exudative vitreoretinopathy (FEVR) comprising 83 affected and nonaffected individuals were studied. Based on the presence of an avascular zone, the clinical diagnosis was made and biometric data of the posterior pole of 57 patients and family members were obtained by the analysis of fundus photographs and compared with the data of 40 controls. The FZD4, LRP5, and NDP genes were screened for mutations in one affected individual per family. The segregation of the gene variants was studied in the corresponding families.
Forty of 83 individuals showed an avascular zone, the most evident clinical sign of FEVR, five showed major signs of FEVR, and 38 persons were not clinically affected. Compared with the control subjects the patients with FEVR had a significantly larger disc-to-macula distance and a significantly smaller optic disc. In 8 of 20 families, a FZD4 mutation was identified, in 2 a mutation in the LRP5 gene, and in 2 a mutation in the NDP gene. Three known and five novel mutations were identified. Nonpenetrance was observed in 26% of the mutation carriers.
Significant anatomic differences were identified between the eyes of patients with FEVR with an avascular zone, when compared with those of the control subjects. In patients with an avascular zone, the optic disc was smaller and the disc-to-macula distance larger than in the control subjects. In 60% of the probands, mutations were identified in one of the three known FEVR genes.
Investigative ophthalmology & visual science 04/2009; 50(9):4379-85. · 3.43 Impact Factor
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Journal of Genetics 01/2009; 87(3):265-9. · 1.09 Impact Factor
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Human Genetics 01/2008; 122(5):553. · 5.07 Impact Factor
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José A J M van den Hurk,
Iwan C Meij,
Maria del Carmen Seleme,
Hiroki Kano,
Konstantinos Nikopoulos,
Lies H Hoefsloot,
Erik A Sistermans,
Ilse J de Wijs, Arijit Mukhopadhyay,
Astrid S Plomp,
Paulus T V M de Jong,
Haig H Kazazian,
Frans P M Cremers
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ABSTRACT: L1 elements are autonomous retrotransposons that can cause hereditary diseases. We have previously identified a full-length L1 insertion in the CHM (choroideremia) gene of a patient with choroideremia, an X-linked progressive eye disease. Because this L1 element, designated L1(CHM), contains two 3'-transductions, we were able to delineate a retrotransposition path in which a precursor L1 on chromosome 10p15 or 18p11 retrotransposed to chromosome 6p21 and subsequently to the CHM gene on chromosome Xq21. A cell culture retrotransposition assay showed that L1(CHM) is one of the most active L1 elements in the human genome. Most importantly, analysis of genomic DNA from the CHM patient's relatives indicated somatic and germ-line mosaicism for the L1 insertion in his mother. These findings provide evidence that L1 retrotransposition can occur very early in human embryonic development.
Human Molecular Genetics 08/2007; 16(13):1587-92. · 7.64 Impact Factor
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ABSTRACT: To identify and evaluate MYOC variant alleles among patients with primary open-angle glaucoma (POAG) and age-matched control subjects in an Indian population.
Three hundred fifteen patients with POAG and 100 unrelated control subjects from the same ethnic background were enrolled in the study. The coding sequence of MYOC was amplified by polymerase chain reaction using genomic DNA, followed by sequencing of the polymerase chain reaction products. Four single nucleotide polymorphisms were genotyped in different Indian subpopulations comprising 1466 individuals using SEQUENOM's homogeneous MassEXTEND assay.
One novel mutation (Gly399Asp), 6 reported mutations (Gln48His, Thr256Met, Thr353Ile, Gln368Stop, Pro370Leu, and Ala427Thr), and 6 single nucleotide polymorphisms were identified in MYOC. Ala427Thr was identified in a patient with POAG and Parkinson disease. Four single nucleotide polymorphisms genotyped in control subjects were highly heterozygous and displayed a similar pattern of linkage disequilibrium among all linguistic groups.
MYOC mutations account for 2.2% of POAG cases. The Gln368Stop mutation (common among persons of the white race) found in 2 families does not seem to be of white race origin. Identification of a MYOC mutation (Ala427Thr) in a patient with POAG and Parkinson disease is interesting with respect to reported interaction of myocilin with synucleins.
Studying the genetics of POAG is helpful for preclinical identification and for better disease management.
Archives of Ophthalmology 07/2007; 125(6):823-9. · 3.71 Impact Factor
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Human Genetics 05/2007; 121(2):290-1. · 5.07 Impact Factor
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ABSTRACT: Glaucoma is the second most prevalent cause of blindness worldwide, projected to affect more than 60 million people by 2010, 75% of which represents primary open angle glaucoma (POAG). Of the three genes, namely, Myocilin (MYOC), Optineurin (OPTN), and WD repeat-containing protein 36 (WDR36), which have been shown to cause POAG when defective, MYOC is the most frequently mutated gene, accounting for 3%-4% of all POAG cases. The purpose of this study was identification and functional characterization of MYOC mutations in adult-onset, high-pressure POAG patients from The Netherlands.
The following criteria were required for study participants to be included: have at least two affected family members, an age of diagnosis of more than 35 years, intraocular pressure (IOP) of more than 22 mmHg, glaucomatous optic neuropathy in both eyes, visual field loss consistent with assessed optic neuropathy in at least one eye, and an open anterior chamber angle without morphological abnormalities by gonioscopy. Sequence analysis was performed in genomic DNA of 30 probands for the protein coding region of the MYOC gene. A Chinese hamster ovarian cell line (CHO-K1) was used to express wild type and mutant MYOC protein. Detergent solubility of MYOC was assayed and its secretory property was analyzed by immunoprecipitation.
We recruited 250 individuals from 30 families (120 affected and 130 unaffected family members) with a positive history of POAG. We identified a novel mutation c.1288T>C (p.Phe430Leu) in exon 3 of MYOC in two unrelated families showing the same haplotype around the mutant allele. The novel mutation segregated completely with the disease in these families and was absent in 250 ethnically matched controls. All patients harboring this mutation showed severe glaucomatous damage, pointing to the deleterious effect of this mutation. Compared to the wild type, the mutant protein was less soluble when extracted with Triton X-100 and was secretion-defective.
The novel MYOC mutation, p.Phe430Leu, has the same origin in both POAG families from The Netherlands. The pathogenic nature of this mutation is suggested by the severe phenotype of mutant patients and mistrafficking of mutant protein as observed for other severe disease-causing mutations of MYOC.
Molecular vision 01/2007; 13:1793-801. · 2.20 Impact Factor
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Arijit Mukhopadhyay,
Konstantinos Nikopoulos,
Alessandra Maugeri,
Arjan P M de Brouwer,
C Eric van Nouhuys,
Camiel J F Boon,
Rahat Perveen,
Hester A A Zegers,
Dienke Wittebol-Post,
Pieter R van den Biesen,
Saskia D van der Velde-Visser,
Han G Brunner,
Graeme C M Black,
Carel B Hoyng,
Frans P M Cremers
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ABSTRACT: Linkage intervals for erosive vitreoretinopathy (ERVR) and Wagner disease previously were found to overlap at 5q14.3. In a Japanese family with Wagner disease, a CSPG2/Versican splice site mutation (c.4004-2A-->G) was recently reported that resulted in a 39-nucleotide exon 8 in-frame deletion. We investigated whether CSPG2/Versican was mutated in six Dutch families and one Chinese family with Wagner disease and in a family with ERVR.
In all families, extensive ophthalmic examinations, haplotype analysis of the 5q14.3 region, and sequence analysis of CSPG2/Versican were performed. The effects of splice site mutations were assessed by reverse transcription-polymerase chain reaction (RT-PCR) and real-time quantitative RT-PCR (QPCR).
Three novel intron 7 sequence variants (c.4004-5T-->C, c.4004-5T-->A, c.4004-1G-->A) were identified in seven families. The c.4004-5T-->C variant was identified in four families with Wagner disease and a family with ERVR. The families were shown to carry the same 5q14.3 haplotype, strongly suggesting that this is a common Dutch founder variant. All three changes segregated with the disease in the respective families and were absent in 250 healthy individuals. In patients with the c.4004-5T-->A and c.4004-1G-->A variants, RT-PCR analysis of CSPG2/Versican showed activation of a cryptic splice site resulting in a 39-nt exon 8 in-frame deletion in splice variant V0. QPCR revealed a highly significant (P < 0.0001) and consistent increase of the V2 (>38-fold) and V3 (>12-fold) splice variants in all patients with intron 7 nucleotide changes and in a Chinese Wagner disease family, in which the genetic defect remains to be found.
Wagner disease and ERVR are allelic disorders. Seven of the eight families exhibit a variant in intron 7 of CSPG2/Versican. The conspicuous clustering of sequence variants in the splice acceptor site of intron 7 and the consistent upregulation of the V2 and V3 isoforms strongly suggest that Wagner disease and ERVR may belong to a largely overlooked group of diseases that are caused by mRNA isoform balance shifts, representing a novel disease mechanism.
Investigative Ophthalmology & Visual Science 08/2006; 47(8):3565-72. · 3.60 Impact Factor
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Human Genetics 08/2005; 117(2-3):299. · 5.07 Impact Factor
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ABSTRACT: Mutations in the Tyrosinase gene (TYR, 11q14-q21) cause oculocutaneous albinism type 1 (OCA1). The 3'-region of the TYR shows 98.55% sequence identity with a pseudogene, known as Tyrosinase-Like Gene (TYRL, 11p11.2-cen). A large number of publicly available nucleotide variants of TYR in this region are same as the bases present in the identical locations in the pseudogene. PCR amplification of these regions using primers with sequences common to both loci may result in coamplification of TYR and TYRL, and may lead to misinterpretation of the results. We have resolved this potential problem using locus-specific amplification conditions that could be used to identify unequivocally mutations and SNPs in exon 4 and exon 5 of TYR and proximal flanking sequences.
Human Mutation 08/2005; 26(1):53-8. · 5.69 Impact Factor
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Subhabrata Chakrabarti,
Kiranpreet Kaur,
Sreelatha Komatireddy,
Moulinath Acharya,
Koilkonda R Devi, Arijit Mukhopadhyay,
Anil K Mandal,
Seyed E Hasnain,
Garudadri Chandrasekhar,
Ravi Thomas,
Kunal Ray
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ABSTRACT: Myocilin gene defects have been originally implicated in primary open angle glaucoma (POAG). Based on multiple reports for the occurrence of Gln48His mutation (c.144G>T; HGMD accession number CM023962) among Indian POAG patients, we wanted to estimate the prevalence of this mutation in primary open angle and primary congenital glaucoma (PCG) in India and assess its role in the causation of the disease.
Two hundred cases each of POAG and PCG were screened for the Gln48His mutation by RFLP (AccI) analysis of the PCR amplicons followed by confirmation of the c.144G>T change by direct sequencing.
The Gln48His mutation was detected in 9 different glaucoma patients (four POAG and five PCG). While all four POAG cases were heterozygous, among PCG cases, four were heterozygous and one exhibited homozygous genotype for the mutation. One each of POAG and PCG patients was detected to be heterozygous for CYP1B1 mutation (c.1656C>T, Pro437Leu) and (c.1449G>A, Arg368His), respectively. None of the 300 ethnically matched normal controls contained either the MYOC or CYP1B1 mutation(s).
The myocilin mutation, Gln48His, represents an allelic condition involving a spectrum of glaucoma phenotypes in Indian populations, and could be a potential risk factor towards disease predisposition among patients of Indian origin. The study also highlights the role of MYOC as a candidate in different glaucoma subtypes that needs to be investigated further.
Molecular vision 03/2005; 11:111-3. · 2.20 Impact Factor
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ABSTRACT: Oculocutaneous albinism (OCA) is a group of autosomal recessive disorders characterized by deficient synthesis of melanin pigment and associated with common developmental abnormalities of the eye. It is one of the major causes of childhood blindness in India. The disease is common among an ethnic group (Tili) of Eastern India, which represents about 12.56% of the Bankura district population (approximately 0.4 million) of West Bengal. The purpose of the study was to investigate the molecular lesions causing OCA within this ethnic group for the unequivocal diagnosis of the carriers and attempt to decipher the cause for the high prevalence of OCA.
Fourteen OCA-affected Tili families consisting a total of 161 individuals, including 26 patients, were recruited for the study. A lack of tyrosinase (TYR) activity among all the patients was ascertained by the tyrosinase hair bulb assay. Mutation screening in the tyrosinase gene (TYR) was done by single strand conformational polymorphism (SSCP) and DNA sequencing. The restriction fragment length polymorphism (RFLP) assay was carried out to determine the frequency of the pathogenic changes among the normal individuals. Haplotype analysis was performed at the TYR locus using a set of informative microsatellite and SNP markers.
All the patients were homozygous for a null mutation (c.832C>T, Arg278stop) in TYR exon 2, which might cause a complete loss of enzyme activity. The mutation occurred in the same haplotype background. The frequency of the disease in this ethnic group was estimated to be significantly higher than the world average.
OCA1 in the Tili population is due to the occurrence of a founder mutation in the TYR as indicated by haplotype analysis. Higher prevalence of the mutation in the population group is due to marriage within the same community. The diagnostic RFLP assay can be utilized for genetic counseling and thereby will help to reduce the disease load on the population.
Molecular vision 02/2005; 11:531-4. · 2.20 Impact Factor
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Arijit Mukhopadhyay,
Sreelatha Komatireddy,
Moulinath Acharya,
Ashima Bhattacharjee,
Anil Kumar Mandal,
Sanjay K D Thakur,
Garudadri Chandrasekhar,
Arun Banerjee,
Ravi Thomas,
Subhabrata Chakrabarti,
Kunal Ray
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ABSTRACT: To evaluate the role of the optineurin gene (OPTN) in Indian primary open angle glaucoma (POAG) patients from different parts of the country.
Two hundred patients with POAG and 200 ethnically matched normal controls were recruited from various parts of India for the study. The entire coding region of OPTN along with the intron-exon boundaries were screened by PCR and single strand conformation polymorphism (SSCP) followed by direct sequencing. A rapid screening method was developed for some of the observed variants by denaturing high performance liquid chromatography (dHPLC). Four variants were also confirmed by digesting the amplicon with appropriate restriction enzymes.
Seven nucleotide changes were observed in OPTN of which one was a putative mutation in exon 16 (Arg545Gln) that was observed in six POAG patients and not in the controls (p<0.05). The remaining variants comprised four single nucleotide polymorphisms (SNPs) in the coding region (Thr34Thr, Met98Lys, Arg149Arg, and Asn303Lys) and two in intron 6 (879-10G>A and 879-5C>T). But frequencies of the minor allele were not significantly different among the patients and controls. The Met98Lys variant that was identified to be a potential risk factor for NTG and POAG in some Asian populations and also for modulating IOP in Caucasian populations, did not exhibit any significant association to the disease phenotype.
Despite a putative mutation (Arg545Gln) in some patients, the present study does not suggest a significant involvement of OPTN in POAG patients of Indian origin.
Molecular vision 01/2005; 11:792-7. · 2.20 Impact Factor
