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Papadopoulou MK, Chatziralli I, Tzika K, Chiras D, Kitsos G, Kroupis C. Correlation of the intronic LOXL1 polymorphism rs11638944 with pseudoexfoliation syndrome and glaucoma in a Greek population. Ophthalmic Genet 2021; 42:405-411. [PMID: 33792495 DOI: 10.1080/13816810.2021.1904420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
BACKGROUND The purpose of this study is the development and validation of a novel and robust genotyping method for a new lysyl oxidase-like 1 (LOXL1) intronic polymorphism (rs11638944, C > G) and the investigation of its potential association with pseudoexfoliation syndrome (PXS) and pseudoexfoliation glaucoma (PXG) in a Greek population. MATERIAL AND METHODS 242 DNA samples from 49 PXS, 64 PXG, 50 primary open-angle glaucoma (POAG) patients and 79 healthy age-matched controls were analyzed. Novel methodologies were developed and optimized, in order to genotype the intronic LOXL1 polymorphism: a) a real-time qPCR and melting curve analysis in the Light Cycler platform for rapid and cost-effective analysis and, b) a conventional PCR-RFLP method for analysis of a small number of samples. In selected samples, validity was checked with the reference DNA Sequencing method. RESULTS The real-time qPCR methodology was reliable, demonstrating good efficiency, reproducibility, accuracy in genotyping (100% concordance with the PCR-RFLP method and DNA Sequencing), with good allele discrimination (Tm = 53.26°C for C allele, Tm = 61.83°C for G allele, ΔTm = 8.57°C). The results were characterized by Hardy-Weinberg equilibrium in all groups. An increase from 18% in healthy controls to 61% in PXS patients was detected for the G/G homozygote thus, the C allele is protective for PXS with OR = 0.22 (95%CI: 0.11-0.42, p < .0001). Moreover, an increase from 18% in healthy controls to 70% in PXG patients was detected for the G/G homozygote thus, the C allele is protective for PXG with OR = 0.13 (95%CI: 0.06-0.25, p < .0001). CONCLUSIONS A statistically significant association was verified for the intronic LOXL1 polymorphism rs11638944 and PXS/PXG in a Greek population.
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Affiliation(s)
- Maria-Kyriaki Papadopoulou
- Department of Clinical Biochemistry and Molecular Diagnostics, Attikon General University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Irini Chatziralli
- 2nd Department of Ophthalmology, Attikon General University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Konstantina Tzika
- Department of Clinical Biochemistry and Molecular Diagnostics, Attikon General University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Dimitrios Chiras
- Department of Ophthalmology, University Hospital of Ioannina, Ioannina, Greece
| | - George Kitsos
- Department of Ophthalmology, University Hospital of Ioannina, Ioannina, Greece
| | - Christos Kroupis
- Department of Clinical Biochemistry and Molecular Diagnostics, Attikon General University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
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Chiras D, Tzika K, Kokotas H, Oliveira SC, Grigoriadou M, Kastania A, Dima K, Stefaniotou M, Aspiotis M, Petersen MB, Kroupis C, Kitsos G. Development of novel LOXL1 genotyping method and evaluation of LOXL1, APOE and MTHFR polymorphisms in exfoliation syndrome/glaucoma in a Greek population. Mol Vis 2013; 19:1006-16. [PMID: 23687437 PMCID: PMC3654845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 05/04/2013] [Indexed: 11/30/2022] Open
Abstract
PURPOSE In the Greek population of Epirus, exfoliation syndrome (XFS) and exfoliation glaucoma (XFG) occur at a high prevalence. In this study, we validate a novel lysyl oxidase-like 1 (LOXL1) genotyping method, investigate the previously reported association of LOXL1 with XFS/XFG, and evaluate apolipoprotein E (APOE) and methylenetetrahydrofolate reductase (MTHFR) polymorphisms as genetic risk factors for both conditions in our population. METHODS Blood samples were collected from 82 patients with XFG, 69 patients with XFS, 52 patients with primary open-angle glaucoma (POAG), and 107 controls. APOE and MTHFR 677C>T genotyping was performed from extracted genomic DNA with established methods. A novel methodology of real-time PCR and melting curve analysis was developed and validated to accurately genotype the LOXL1 G153D and R141L polymorphisms by using two different fluorescent channels of the LightCycler instrument (Roche) examining each SNP separately. RESULTS No significant differences were observed for the APOE and MTHFR polymorphisms between the patients with XFS, the patients with XFG, and the control subjects. The APOE ε2 allele appears to be associated with elevated risk of POAG in our population. Our novel LOXL1 genotyping method was easy to perform, fast, and accurate. A statistically significant association was found for the LOXL1 gene with XFS/XFG in this Greek population. The association of XFS and XFG with G153D appeared to be less powerful in this population (XFS: odds ratio [OR]=2.162, p=0.039, XFG: OR=2.794, p=0.002) compared to other populations, and for R141L, the association was proven only with XFG (OR=3.592, p<0.001). Neither of the two LOXL1 SNPs was significantly associated with POAG. CONCLUSIONS We confirmed the association between LOXL1 and XFS/XFG, but the APOE and MTHFR polymorphisms are not significant risk factors for the development of XFS/XFG in our population of patients from Epirus (Greece).
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Affiliation(s)
- Dimitrios Chiras
- Department of Ophthalmology, University Hospital of Ioannina, Ioannina, Greece,Department of Ophthalmology, «Aghios Savvas» Hospital, Athens, Greece
| | - Konstantina Tzika
- Department of Clinical Biochemistry, Attikon University General Hospital, Athens, Greece
| | - Haris Kokotas
- Department of Genetics, Institute of Child Health, Athens, Greece
| | - Samantha C. Oliveira
- Department of Clinical Biochemistry, Attikon University General Hospital, Athens, Greece
| | | | - Anastasia Kastania
- Department of Informatics, Athens University of Economics and Business, Athens, Greece
| | - Kleanthi Dima
- Department of Clinical Biochemistry, Attikon University General Hospital, Athens, Greece
| | - Maria Stefaniotou
- Department of Ophthalmology, University Hospital of Ioannina, Ioannina, Greece
| | - Miltiadis Aspiotis
- Department of Ophthalmology, University Hospital of Ioannina, Ioannina, Greece
| | - Michael B. Petersen
- Department of Genetics, Institute of Child Health, Athens, Greece,Department of Clinical Genetics, Aalborg University Hospital, Aalborg, Denmark
| | - Christos Kroupis
- Department of Clinical Biochemistry, Attikon University General Hospital, Athens, Greece
| | - George Kitsos
- Department of Ophthalmology, University Hospital of Ioannina, Ioannina, Greece
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