Purchase this article with an account.
J.L. Wiggs, D. Figueiredo, J. Auguste, D. Elizabeth, J. Haines; Evaluation of MTHFR Polymorphisms in Patients With Pseudoexfoliation Syndrome . Invest. Ophthalmol. Vis. Sci. 2005;46(13):37.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: Recent studies have indicated that plasma and aqueous humor levels of homocysteine are elevated in patients with pseudoexfoliation syndrome. These results suggest that moderate hyperhomocysteinemia may be associated with pseudoexfoliation and may contribute to the vascular abnormalities seen in this syndrome. To determine if the elevation of homocysteine in pseudoexfoliation has a genetic etiology, we evaluated the distribution of alleles at two polymorphic sites in the gene for the enzyme methylenetetrahydrofolate reductase (MTHFR), which is a critical component of homocysteine metabolism. Methods: 84 patients with pseudoexfoliation syndrome (PXF), 201 patients affected with adult onset primary open angle glaucoma (POAG), 65 patients affected with low tension glaucoma (LTG), and 107 control patients without either glaucoma or PXF were used for this study. POAG was defined as age of diagnosis greater than 35, intraocular pressure greater than 22 mm Hg in both eyes, glaucomatous optic nerve damage in both eyes, and visual field loss in at least one eye. Low tension glaucoma patients had evidence of optic nerve disease and visual field defects with intraocular pressure less than 22 mm Hg. PXF patients had evidence of characteristic pseudoexfoliative material on the lens capsule or pupillary margin. Two well–studied polymorphisms of the MTHFR gene, C677T, and A1298C were selected for this study. Alleles were identified by sequencing after PCR amplification of genomic DNA. Results: The distribution of genotypes for the C677T polymorphism (0.10 TT, 0.33 CT, 0.57 CC) and the A1298C polymorphism (0.25 CC, 0.26 AC, 0.49 AA) in the PXF patients in this study did not differ significantly from those of the POAG or LTG patients or the control patients. The allele frequencies were also similar to those previously published for other control populations. Conclusions: These results suggest that the MTHFR polymorphisms C677T and A1298C do not contribute to an elevation of homocysteine in the pseudoexfoliation patients evaluated in this study. A number of other enzymes are also involved in homocysteine metabolism and may contribute to this syndrome including methionine synthase, methionine synthase reductase and cystathionine beta–synthase. Evaluation of polymorphic forms of these enzymes in pseudoexfoliation patients is currently underway.
This PDF is available to Subscribers Only