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Berdahl JP, Fleischman D, Zaydlarova J, Stinnett S, Allingham RR, Fautsch MP. Body mass index has a linear relationship with cerebrospinal fluid pressure. Invest Ophthalmol Vis Sci 2012; 53:1422-7. [PMID: 22323469 DOI: 10.1167/iovs.11-8220] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To examine the relationship between body mass index (BMI) and cerebrospinal fluid pressure (CSFP), as low BMI and low CSFP have recently been described as risk factors for primary open-angle glaucoma (POAG). METHODS This was a retrospective review of the electronic medical records of patients who had CSFP measured by lumbar puncture and data to calculate BMI at the Mayo Clinic (Rochester, MN). Exclusion criteria included diagnoses, surgical procedures and medications known to affect CSFP. Mean CSFP for each unit BMI was calculated. The probabilities were two-tailed, and the α level was set at P < 0.05. Patients with documented BMI, CSFP, and intraocular pressure (IOP) were analyzed for the relationship between IOP and BMI. RESULTS A total of 4235 patients, primarily of Caucasian descent, met the entry criteria. Median BMI was 26 and the mean CSFP was 10.9 ± 2.6 mm Hg. The increase in CSFP with increasing BMI was linear with an r(2) = 0.20 (P < 0.001). CSFP increased by 37.7% from BMI 18 (8.6 ± 2.1 mm Hg) to BMI 39 (14.1 ± 2.5 mm Hg). The r(2) (0.21) of the model of BMI and sex was similar to the r(2) of a BMI-only model (0.20). There was no relation between IOP and BMI within a subgroup of the study population (r (2) = 0.005; P = 0.14). CONCLUSIONS CSFP has a positive, linear relationship with BMI. IOP is not influenced by BMI. If CSFP influences the risk for POAG, then individuals with a lower BMI may have an increased risk for developing POAG. Similarly, a higher BMI may be protective.
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Kawase K, Allingham RR, Meguro A, Mizuki N, Roos B, Solivan-Timpe FM, Robin AL, Ritch R, Fingert JH. Confirmation of TBK1 duplication in normal tension glaucoma. Exp Eye Res 2012; 96:178-80. [PMID: 22306015 DOI: 10.1016/j.exer.2011.12.021] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Revised: 12/21/2011] [Accepted: 12/27/2011] [Indexed: 11/15/2022]
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Abstract
Keratoconus is the most common ectatic disorder of the corneal. Genetic and environmental factors may contribute to its pathogenesis. The focus of this article is to summarize current research into the complex genetics of keratoconus. We discuss the evidence of genetic etiology including family-based linkage studies, twin studies, genetic mutations, and genome-wide association studies. The genes implicated potentially include VSX1, miR-184, DOCK9, SOD1, RAB3GAP1, and HGF. Besides the coding mutations, we also highlight the potential contribution of DNA copy number variants in the pathogenesis of keratoconus. Finally, we present future directions for genetic research in the understanding of the complex genetics of keratoconus and its clinical significance. As new functional, candidate genes for keratoconus are being discovered at a rapid pace, the molecular genetic mechanisms underlying keratoconus pathogenesis will advance our understanding of keratoconus and promote the development of a novel therapy.
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Abu-Amero KK, Osman EA, Mousa A, Wheeler J, Whigham B, Allingham RR, Hauser MA, Al-Obeidan SA. Screening of CYP1B1 and LTBP2 genes in Saudi families with primary congenital glaucoma: genotype-phenotype correlation. Mol Vis 2011; 17:2911-9. [PMID: 22128238 PMCID: PMC3224840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Accepted: 11/07/2011] [Indexed: 10/26/2022] Open
Abstract
PURPOSE Primary congenital glaucoma (PCG) is a severe form of glaucoma that presents early in life. PCG is a clinical and genetic entity that is distinct from juvenile forms of glaucoma. Inheritance is usually autosomal recessive and therefore the disease might be more common in societies where consanguinity is high. We studied the prevalence of cytochrome P450, family 1, subfamily B, polypeptide 1 (CYP1B1) and latent-transforming growth factor beta-binding protein 2 (LTBP2) mutations in a group of Saudi PCG patients and attempted to correlate the mutation status with the disease severity. METHODS Genomic DNA was collected from 54 unrelated Saudi PCG families (74 patients) who were diagnosed as having PCG by standard ophthalmological examinations and screened for mutations in CYP1B1 and LTBP2 by sequencing. We also examined the effect of mutations on the phenotype of patients with PCG (phenotype-genotype correlation). RESULTS Mutations in CYP1B1 were identified in 41 (75.9%) of affected patients. No mutation in CYP1B1 was found in 13 (24.1%) affected persons. We detected a total of 13 mutations: 9 missense mutations (G61E, A119S, R390H, P437L, D441G, A443G, G466S, G466D, and R469W), 2 deletions (g.4238_4247del and g.7901_7913del), and 2 nonsense mutations (R355X and R444X). Two mutations, G466S and D441G, were novel. The G61E mutation was by far the most common mutation detected. PCG cases with CYP1B1 mutation(s) presented with a high degree of haze and greater cup/disc ratio than those with no mutation(s). Also, PCG cases with a mutation had higher post operative indices in terms of post operative haze and the need for anti-glaucoma medications. Additionally, the surgical success rate was higher 13/14 (92.9%) among cases without mutation than those with mutation 42/60 (70%). No mutation(s) were found in LTBP2 in any of the tested patients. CONCLUSIONS CYP1B1 mutations are the predominant cause of PCG in the Saudi Arabian population with G61E as the dominant disease-associated allele. PCG cases with a mutation had higher last postoperative visit indices in terms of postoperative haze and the need for anti-glaucoma medications. This will be a valuable parameter in predicting disease severity earlier on and might help in predicting the surgical outcome.
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Liu Y, Gibson J, Wheeler J, Kwee LC, Santiago-Turla CM, Akafo SK, Lichter PR, Gaasterland DE, Moroi SE, Challa P, Herndon LW, Girkin CA, Budenz DL, Richards JE, Allingham RR, Hauser MA. GALC deletions increase the risk of primary open-angle glaucoma: the role of Mendelian variants in complex disease. PLoS One 2011; 6:e27134. [PMID: 22073273 PMCID: PMC3208571 DOI: 10.1371/journal.pone.0027134] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Accepted: 10/11/2011] [Indexed: 11/19/2022] Open
Abstract
DNA copy number variants (CNVs) have been reported in many human diseases including autism and schizophrenia. Primary Open Angle Glaucoma (POAG) is a complex adult-onset disorder characterized by progressive optic neuropathy and vision loss. Previous studies have identified rare CNVs in POAG; however, their low frequencies prevented formal association testing. We present here the association between POAG risk and a heterozygous deletion in the galactosylceramidase gene (GALC). This CNV was initially identified in a dataset containing 71 Caucasian POAG cases and 478 ethnically matched controls obtained from dbGAP (study accession phs000126.v1.p1.) (p = 0.017, fisher's exact test). It was validated with array comparative genomic hybridization (arrayCGH) and realtime PCR, and replicated in an independent POAG dataset containing 959 cases and 1852 controls (p = 0.021, OR (odds ratio) = 3.5, 95% CI -1.1-12.0). Evidence for association was strengthened when the discovery and replication datasets were combined (p = 0.002; OR = 5.0, 95% CI 1.6-16.4). Several deletions with different endpoints were identified by array CGH of POAG patients. Homozygous deletions that eliminate GALC enzymatic activity cause Krabbe disease, a recessive Mendelian disorder of childhood displaying bilateral optic neuropathy and vision loss. Our findings suggest that heterozygous deletions that reduce GALC activity are a novel mechanism increasing risk of POAG. This is the first report of a statistically-significant association of a CNV with POAG risk, contributing to a growing body of evidence that CNVs play an important role in complex, inherited disorders. Our findings suggest an attractive biomarker and potential therapeutic target for patients with this form of POAG.
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Asrani S, Rosdahl JA, Allingham RR. Novel software strategy for glaucoma diagnosis: asymmetry analysis of retinal thickness. ACTA ACUST UNITED AC 2011; 129:1205-11. [PMID: 21911669 DOI: 10.1001/archophthalmol.2011.242] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The benefits of high-speed, detailed retinal thickness measurement by spectral-domain optical coherence tomography in glaucoma diagnosis have not been fully realized. We have modified the software protocols for such measurement and applied it for diagnosis at different stages of glaucoma. Using the Spectralis SD-OCT (Heidelberg Engineering, Carlsbad, California), we have customized the retinal thickness protocol to acquire detailed retinal thickness measurements of the central 20° of the posterior pole. These custom maps are displayed in a compressed color scale that reveals small losses in retinal thickness. A novel asymmetry analysis protocol was created to highlight differences between the eyes and the 2 hemispheres within each eye. We present case examples illustrating the ability of this strategy to detect glaucomatous defects, showing the promise of the protocol in the diagnosis and management of glaucoma.
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Liu Y, Allingham RR. Molecular genetics in glaucoma. Exp Eye Res 2011; 93:331-9. [PMID: 21871452 DOI: 10.1016/j.exer.2011.08.007] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Revised: 08/09/2011] [Accepted: 08/11/2011] [Indexed: 01/07/2023]
Abstract
Glaucoma is a family of diseases whose pathology is defined by the progressive loss of retinal ganglion cells. Clinically, glaucoma presents as a distinctive optic neuropathy with associated visual field loss. Primary open-angle glaucoma (POAG), chronic angle-closure glaucoma (ACG), and exfoliation glaucoma (XFG) are the most prevalent forms of glaucoma globally and are the most common causes of glaucoma-related blindness worldwide. A host of genetic and environmental factors contribute to glaucoma phenotypes. This review examines the current status of genetic investigations of POAG, ACG, XFG, including the less common forms of glaucoma primary congenital glaucoma (PCG), the developmental glaucomas, and pigment dispersion glaucoma.
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Fleischman D, Allingham RR, Berdahl J, Fautsch M. Body mass, spinal fluid, and glaucoma. Ophthalmology 2011; 118:1225-6; author reply 1226. [PMID: 21640274 DOI: 10.1016/j.ophtha.2011.01.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2010] [Accepted: 01/07/2011] [Indexed: 11/28/2022] Open
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Whigham BT, Allingham RR. Review: The role of LOXL1 in exfoliation syndrome/glaucoma. Saudi J Ophthalmol 2011; 25:347-52. [PMID: 23960948 DOI: 10.1016/j.sjopt.2011.07.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Revised: 07/14/2011] [Accepted: 07/18/2011] [Indexed: 11/27/2022] Open
Abstract
Exfoliation syndrome is a common cause of open-angle glaucoma. It is characterized by microscopic flakes of protein-rich material being deposited in both ocular and non-ocular tissues. While its mechanism is poorly understood, family- and population-based studies have established that the disorder has a strong genetic component. A further understanding of the relevant gene variants might help reveal the molecular mechanism behind exfoliation. The most-strongly associated genetic variants are found in the lysyl oxidase-like 1 (LOXL1) gene. However, two major risk alleles in the LOXL1 coding region are reversed between ethnic groups. It now appears the strong association between LOXL1 and XFS is due to non-coding variants that have not yet been identified. Such variants might alter LOXL1 expression, which is decreased in the late stages of exfoliation syndrome/glaucoma. Here we discuss LOXL1 as a risk gene for exfoliation syndrome and glaucoma.
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Crooks KR, Allingham RR, Qin X, Liu Y, Gibson JR, Santiago-Turla C, Larocque-Abramson KR, Del Bono E, Challa P, Herndon LW, Akafo S, Wiggs JL, Schmidt S, Hauser MA. Genome-wide linkage scan for primary open angle glaucoma: influences of ancestry and age at diagnosis. PLoS One 2011; 6:e21967. [PMID: 21765929 PMCID: PMC3134467 DOI: 10.1371/journal.pone.0021967] [Citation(s) in RCA: 14] [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: 02/01/2011] [Accepted: 06/15/2011] [Indexed: 11/18/2022] Open
Abstract
Primary open-angle glaucoma (POAG) is the most common form of glaucoma and one of the leading causes of vision loss worldwide. The genetic etiology of POAG is complex and poorly understood. The purpose of this work is to identify genomic regions of interest linked to POAG. This study is the largest genetic linkage study of POAG performed to date: genomic DNA samples from 786 subjects (538 Caucasian ancestry, 248 African ancestry) were genotyped using either the Illumina GoldenGate Linkage 4 Panel or the Illumina Infinium Human Linkage-12 Panel. A total of 5233 SNPs was analyzed in 134 multiplex POAG families (89 Caucasian ancestry, 45 African ancestry). Parametric and non-parametric linkage analyses were performed on the overall dataset and within race-specific datasets (Caucasian ancestry and African ancestry). Ordered subset analysis was used to stratify the data on the basis of age of glaucoma diagnosis. Novel linkage regions were identified on chromosomes 1 and 20, and two previously described loci-GLC1D on chromosome 8 and GLC1I on chromosome 15--were replicated. These data will prove valuable in the context of interpreting results from genome-wide association studies for POAG.
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Whigham BT, Williams SE, Liu Y, Rautenbach RM, Carmichael TR, Wheeler J, Ziskind A, Qin X, Schmidt S, Ramsay M, Hauser MA, Allingham RR. Myocilin mutations in black South Africans with POAG. Mol Vis 2011; 17:1064-9. [PMID: 21552496 PMCID: PMC3086605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Accepted: 04/14/2011] [Indexed: 11/10/2022] Open
Abstract
PURPOSE Myocilin (MYOC) mutations are associated with primary open-angle glaucoma (POAG) in multiple populations. Here we examined the role of MYOC mutations in a black South African population with primary open-angle glaucoma (POAG). METHODS Unrelated black South African subjects with POAG and unaffected controls were recruited from the St. John Eye Hospital (Soweto, Johannesburg, South Africa) and East London Hospital Complex (Eastern Cape, South Africa). A complete eye examination including visual field assessment was performed in all subjects. Blood samples were obtained for DNA extraction. The complete coding region of MYOC was sequenced using the PCR-based Sanger method. Identified mutations were compared to known MYOC mutations. RESULTS One hundred-thirteen POAG cases and 131 controls were recruited for analysis. A total of 19 variants were observed. Probable glaucoma-causing mutations were observed in 4.4% of POAG cases. A previously reported glaucoma-causing mutation, Tyr453MetfsX11, was observed in three cases and one control. Two other sequence variants, Gly374Val and Lys500Arg, occurred only in cases. Other sequence variants, including 6 novel variants, occurred in at least one control. CONCLUSIONS A small minority of black South Africans with POAG carry MYOC mutations. The Gly374Val mutation might represent a novel glaucoma-causing mutation. The Tyr453MetFSX11 mutation appears to be a glaucoma-causing mutation with incomplete penetrance.
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Abu-Amero KK, Osman EA, Azad MT, Allingham RR, Hauser MA, Al-Obeidan SA. Lack of association between LOXL1 gene polymorphisms and primary open angle glaucoma in the Saudi Arabian population. Ophthalmic Genet 2011; 33:130-3. [PMID: 21510775 DOI: 10.3109/13816810.2011.575430] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To investigate whether major single nucleotide polymorphisms (SNPs) in the LOXL1 gene associated with pseudoexfoliation glaucoma are associated with primary open angle glaucoma (POAG) in the Saudi Arabian population. METHODS The regions of the LOXL1 gene associated with pseudoexfoliation glaucoma, encompassing the three common SNPs, (rs1048661, rs3825942 and rs2165241), were sequenced in a Saudi Arabian dataset consisting of 96 POAG cases and 101 healthy controls. RESULTS The allele frequency of the G exfoliation risk allele for SNP rs1048661 in POAG cases and controls was 0.75 and 0.76 (p = 0.886), respectively and the allele frequency difference was not statistically significant (p = 0.866). There was no statistically significant difference in the genotypes between patients and controls (p = 0.261 and 0.156 for genotypes G/G and G/T respectively). As for SNP rs3825942, the frequency of the "G" allele in the POAG patients was comparable to that in the controls (p = 0.477) and there was no statistically significant difference in genotype G/G and A/G frequency in the study groups. As for SNP rs2165241, the "T" allele frequency in the POAG patients (0.46) was slightly higher than the frequency in controls (0.39), but this difference was not statistically significant (p = 0.176). CONCLUSION The Saudi Arabian POAG population, similar to all other populations studied to date, demonstrates no association with SNPs associated with pseudoexfoliation glaucoma.
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Li YJ, Minear MA, Rimmler J, Zhao B, Balajonda E, Hauser MA, Allingham RR, Eghrari AO, Riazuddin SA, Katsanis N, Gottsch JD, Gregory SG, Klintworth GK, Afshari NA. Replication of TCF4 through association and linkage studies in late-onset Fuchs endothelial corneal dystrophy. PLoS One 2011; 6:e18044. [PMID: 21533127 PMCID: PMC3080358 DOI: 10.1371/journal.pone.0018044] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Accepted: 02/22/2011] [Indexed: 11/19/2022] Open
Abstract
Fuchs endothelial corneal dystrophy (FECD) is a common, late-onset disorder of the corneal endothelium. Although progress has been made in understanding the genetic basis of FECD by studying large families in which the phenotype is transmitted in an autosomal dominant fashion, a recently reported genome-wide association study identified common alleles at a locus on chromosome 18 near TCF4 which confer susceptibility to FECD. Here, we report the findings of our independent validation study for TCF4 using the largest FECD dataset to date (450 FECD cases and 340 normal controls). Logistic regression with sex as a covariate was performed for three genetic models: dominant (DOM), additive (ADD), and recessive (REC). We found significant association with rs613872, the target marker reported by Baratz et al.(2010), for all three genetic models (DOM: P = 9.33×10(-35); ADD: P = 7.48×10(-30); REC: P = 5.27×10(-6)). To strengthen the association study, we also conducted a genome-wide linkage scan on 64 multiplex families, composed primarily of affected sibling pairs (ASPs), using both parametric and non-parametric two-point and multipoint analyses. The most significant linkage region localizes to chromosome 18 from 69.94cM to 85.29cM, with a peak multipoint HLOD = 2.5 at rs1145315 (75.58cM) under the DOM model, mapping 1.5 Mb proximal to rs613872. In summary, our study presents evidence to support the role of the intronic TCF4 single nucleotide polymorphism rs613872 in late-onset FECD through both association and linkage studies.
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Liu Y, Munro D, Layfield D, Dellinger A, Walter J, Peterson K, Rickman CB, Allingham RR, Hauser MA. Serial analysis of gene expression (SAGE) in normal human trabecular meshwork. Mol Vis 2011; 17:885-93. [PMID: 21528004 PMCID: PMC3081805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Accepted: 03/29/2011] [Indexed: 11/05/2022] Open
Abstract
PURPOSE To identify the genes expressed in normal human trabecular meshwork tissue, a tissue critical to the pathogenesis of glaucoma. METHODS Total RNA was extracted from human trabecular meshwork (HTM) harvested from 3 different donors. Extracted RNA was used to synthesize individual SAGE (serial analysis of gene expression) libraries using the I-SAGE Long kit from Invitrogen. Libraries were analyzed using SAGE 2000 software to extract the 17 base pair sequence tags. The extracted sequence tags were mapped to the genome using SAGE Genie map. RESULTS A total of 298,834 SAGE tags were identified from all HTM libraries (96,842, 88,126, and 113,866 tags, respectively). Collectively, there were 107,325 unique tags. There were 10,329 unique tags with a minimum of 2 counts from a single library. These tags were mapped to known unique Unigene clusters. Approximately 29% of the tags (orphan tags) did not map to a known Unigene cluster. Thirteen percent of the tags mapped to at least 2 Unigene clusters. Sequence tags from many glaucoma-related genes, including myocilin, optineurin, and WD repeat domain 36, were identified. CONCLUSIONS This is the first time SAGE analysis has been used to characterize the gene expression profile in normal HTM. SAGE analysis provides an unbiased sampling of gene expression of the target tissue. These data will provide new and valuable information to improve understanding of the biology of human aqueous outflow.
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DeCroos FC, Kondo Y, Mordes D, Lee MR, Ahmad S, Asrani S, Allingham RR, Olbrich KC, Klitzman B. In VitroFluid Dynamics of the Ahmed Glaucoma Valve Modified with Expanded Polytetrafluoroethylene. Curr Eye Res 2011; 36:112-7. [DOI: 10.3109/02713683.2010.512115] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Abu-Amero KK, Osman EA, Dewedar AS, Schmidt S, Allingham RR, Al-Obeidan SA. Analysis of LOXL1 polymorphisms in a Saudi Arabian population with pseudoexfoliation glaucoma. Mol Vis 2010; 16:2805-10. [PMID: 21197115 PMCID: PMC3008719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Accepted: 12/12/2010] [Indexed: 11/04/2022] Open
Abstract
PURPOSE To investigate whether single nucleotide polymorphisms (SNPs) in the lysyl oxidase-like 1 (LOXL1) gene are associated with pseudoexfoliation glaucoma (PEG) in the Saudi Arabian population. METHODS The coding regions of LOXL1 were fully sequenced in 93 clinically diagnosed PEG patients and 101 healthy controls. Both groups were Saudi Arabs. Previously reported and newly identified SNPs were evaluated for possible association with PEG and their pathological consequences on the gene were assessed. RESULTS The "G" allele frequencies of both rs1048661 and rs3825942 SNPs differed between PEG patients and control subjects from Saudi Arabia (p=0.0056 and p=0.000005, respectively). This significance remained after applying the Bonferroni correction. Two non-synonymous novel SNPs in LOXL1 were detected in the PEG patients and not in the controls. One of these SNPs was in exon 4 (g.25722 C>G; codon change D484E) of LOXL1 and was predicted to be non-pathological; the other was in exon 6 of LOXL1 (g.28084 T>G; codon change Y559D) and was predicted to be probably damaging. All alleles of SNPs (rs28706550, rs35203737, rs41429348, rs12906373, rs41435250, and rs13329473) were monoallelic in this population. No allele frequency difference for rs8818 and rs3522 SNP between patients and controls (p values were 0.126 and 0.994 respectively). CONCLUSIONS Similar to almost all non-African populations tested thus far, the "G" allele of both rs1048661 and rs3825942 SNPs were associated with the risk of PEG in the Saudi Arab population.
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Williams SE, Whigham BT, Liu Y, Carmichael TR, Qin X, Schmidt S, Ramsay M, Hauser MA, Allingham RR. Major LOXL1 risk allele is reversed in exfoliation glaucoma in a black South African population. Mol Vis 2010; 16:705-12. [PMID: 20431720 PMCID: PMC2861124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Accepted: 04/14/2010] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To investigate whether variants in the lysyl oxidase-like 1 (LOXL1) gene are associated with exfoliation glaucoma (XFG) and primary open-angle glaucoma (POAG) in an ancestral population from South Africa. METHODS Black South African subjects with XFG, POAG, and age matched unaffected controls were recruited from the St. John Eye Hospital in Soweto, Johannesburg, South Africa, using standard clinical examination techniques. Fifty individuals were collected for each of the three groups: XFG, POAG, and normal controls. The complete coding region of LOXL1 was sequenced using the PCR-based Sanger method. The allele frequencies of the identified sequence variants were compared between XFG or POAG and controls using Fisher's exact test. RESULTS A large number of coding variants were identified, including rs1048661 (R141L), rs3825942 (G153D), S159A, S161L, rs41435250 (A320A), rs13329473 (F489F), and T567A. The allele frequencies of both rs3825942 and rs1048661 differed significantly between the XFG and control subjects from South Africa (p=5.2 x 10(-13) and 1.7 x 10(-5), respectively). The G allele for rs1048661 (encoding arginine) was the risk allele which is similar to other populations. The A allele of rs3825942 (encoding aspartic acid) was the risk allele, in sharp contrast to the G allele (encoding glycine) reported in multiple other populations. There was no significant difference in the allele frequencies of coding variants in LOXL1 between POAG and control subjects. CONCLUSIONS This represents the first genetic association study of LOXL1 in an ancestral African population with XFG. We have confirmed the association between variants of LOXL1 and XFG. To date, the G allele of the major susceptibility variant rs3825942 has consistently been shown in multiple populations to increase the risk of XFG. Surprisingly, we have found a strong association with the opposite allele in the South African population. This suggests that other as yet unknown causal variants of LOXL1 contribute to the genetic risk of XFG.
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Liu Y, Liu W, Crooks K, Schmidt S, Allingham RR, Hauser MA. No evidence of association of heterozygous NTF4 mutations in patients with primary open-angle glaucoma. Am J Hum Genet 2010; 86:498-9; author reply 500. [PMID: 20215012 DOI: 10.1016/j.ajhg.2009.11.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2009] [Revised: 11/16/2009] [Accepted: 11/16/2009] [Indexed: 11/19/2022] Open
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Hunter TG, Chong GT, Asrani S, Allingham RR, Blumberg DM. Simultaneous Bilateral Angle Closure Glaucoma in a Patient With Giant Cell Arteritis. J Glaucoma 2010; 19:149-50. [DOI: 10.1097/ijg.0b013e3181a98f03] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Liu W, Liu Y, Qin XJ, Schmidt S, Hauser MA, Allingham RR. AQP1 and SLC4A10 as candidate genes for primary open-angle glaucoma. Mol Vis 2010; 16:93-7. [PMID: 20101282 PMCID: PMC2810210] [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: 12/01/2009] [Accepted: 01/15/2010] [Indexed: 12/05/2022] Open
Abstract
PURPOSE Recent evidence supports the role of reduced cerebrospinal fluid (CSF) pressure in the pathogenesis of primary open-angle glaucoma (POAG). We investigated the association of variants in two candidate genes that are important in CSF production, aquaporin 1 (AQP1) and solute carrier family 4, sodium bicarbonate transporter, member 10 (SLC4A10), with POAG in the Caucasian population. METHODS POAG subjects (n=382) met the criteria of glaucomatous optic neuropathy with consistent visual field loss. Intraocular pressure was not used as an inclusion criterion. Control subjects (n=363) did not meet any of the inclusion criteria and had no family history of glaucoma. Eleven tagging single nucleotide polymorphisms (SNPs) for AQP1 and SLC4A10 were genotyped in the POAG and control subjects, using allelic discrimination assays. Genotype frequencies were compared between the POAG and control subjects, using logistic regression adjusted for gender. RESULTS There was no statistically significant difference in genotype frequencies between POAG and control subjects for any of the tested SNPs in AQP1 and SLC4A10 (p>0.05). CONCLUSIONS There was no association between common sequence variants in the AQP1 or SLC4A10 genes and POAG in the Caucasian population. This is the first study to investigate the association between these two candidate genes and increased risk for POAG.
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DeCroos FC, Ahmad S, Kondo Y, Chow J, Mordes D, Lee MR, Asrani S, Allingham RR, Olbrich KC, Klitzman B. Expanded polytetrafluoroethylene membrane alters tissue response to implanted Ahmed glaucoma valve. Curr Eye Res 2009; 34:562-7. [PMID: 19899969 DOI: 10.1080/02713680902963167] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
PURPOSE Long-term intraocular pressure control by glaucoma drainage implants is compromised by the formation of an avascular fibrous capsule that surrounds the glaucoma implant and increases aqueous outflow resistance. It is possible to alter this fibrotic tissue reaction and produce a more vascularized and potentially more permeable capsule around implanted devices by enclosing them in a porous membrane. METHODS Ahmed glaucoma implants modified with an outer 5-microm pore size membrane (termed porous retrofitted implant with modified enclosure or PRIME-Ahmed) and unmodified glaucoma implants were implanted into paired rabbit eyes. After 6 weeks, the devices were explanted and subject to histological analysis. RESULTS A tissue response containing minimal vascularization, negligible immune response, and a thick fibrous capsule surrounded the unmodified Ahmed glaucoma implant. In comparison, the tissue response around the PRIME-Ahmed demonstrated a thinner fibrous capsule (46.4 +/- 10.8 microm for PRIME-Ahmed versus 94.9 +/- 21.2 microm for control, p < 0.001) and was highly vascularized near the tissue-material interface. A prominent chronic inflammatory response was noted as well. CONCLUSIONS Encapsulating the aqueous outflow pathway with a porous membrane produces a more vascular tissue response and thinner fibrous capsule compared with a standard glaucoma implant plate. Enhanced vascularity and a thinner fibrous capsule may reduce aqueous outflow resistance and improve long-term glaucoma implant performance.
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Berdahl JP, Allingham RR. Cerebrospinal fluid pressure may play a role in reversal of cupping after glaucoma surgery. Am J Ophthalmol 2009; 148:623-4; author reply 624-5. [PMID: 19782798 DOI: 10.1016/j.ajo.2009.06.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2009] [Accepted: 06/01/2009] [Indexed: 11/25/2022]
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Berdahl JP, Ethier CR, Allingham RR. Cerebrospinal fluid pressure and glaucomatous optic disc cupping. Graefes Arch Clin Exp Ophthalmol 2009; 247:1289-90; author reply 1291-4. [PMID: 19444463 DOI: 10.1007/s00417-009-1110-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2009] [Accepted: 04/28/2009] [Indexed: 12/31/2022] Open
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Liu Y, Akafo S, Santiago-Turla C, Cohen CS, LaRocque-Abramson KR, Qin X, Herndon LW, Challa P, Schmidt S, Hauser MA, Allingham RR. Optineurin coding variants in Ghanaian patients with primary open-angle glaucoma. Mol Vis 2008; 14:2367-72. [PMID: 19096531 PMCID: PMC2605106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2008] [Accepted: 12/08/2008] [Indexed: 12/03/2022] Open
Abstract
PURPOSE Coding variants in the optineurin gene (OPTN, GLC1E) have been reported to play a role in primary open-angle glaucoma (POAG) in various populations. This study investigated the role of OPTN sequence variants in patients with POAG in Ghana (West Africa). METHODS This is a case-control study of unrelated Ghanaian POAG cases and non-glaucomatous controls. Ascertainment criteria for POAG included the presence of glaucomatous optic nerve neuropathy, associated visual field loss, and elevated intraocular pressure (IOP) in both eyes, all in the absence of secondary causes of glaucoma. Controls had normal optic nerves, visual fields, and IOP. All the coding exons of OPTN were polymerase chain reaction (PCR) amplified and sequenced in all 140 cases and 130 controls using an ABI 3730 DNA analyzer. RESULTS All the coding exons of OPTN were sequenced in 140 POAG patients and 130 controls. Several coding variants were identified including M98K, A134A, V147L, P292P, A301G, S321S, and E322K. Three coding variants (V147L, P292P, and A301G) have not been reported previously. There were no significant differences on the frequencies of all the identified variants between POAG cases and controls in this population. CONCLUSIONS This is the first comprehensive study of OPTN in a single West African population. Our results suggest that coding variants in OPTN may not contribute to the risk for POAG in persons of West African descent.
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Berdahl JP, Allingham RR. Author reply. Ophthalmology 2008. [DOI: 10.1016/j.ophtha.2008.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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