Molecular Analysis of the Myocilin Gene in Chinese Subjects With Chronic Primary Angle Closure Glaucoma

Abstract

Abstract: : Purpose: Mutations in the myocilin (MYOC) gene have been implicated in juvenile as well as late–onset primary open angle glaucoma (POAG). Overall, MYOC mutations account for 3–5% of cases of POAG worldwide, making it the most significant gene identified so far in glaucoma. Although there are some similarities in the phenotype of POAG and in particular chronic primary angle closure glaucoma (PACG), little is known about the role of MYOC in the causation of PACG. To address this we screened the MYOC gene in a cohort of 106 chronic PACG patients Methods: Genomic DNA was extracted from leukocytes of the peripheral blood and exons 1 to 3 of MYOC gene were PCR amplified and then subjected to bi–directional sequencing and analysis. Results: One hundred and six chronic PACG patients of Chinese ethnicity were studied. Sequencing of the MYOC gene in these patients revealed eight sequence variants. Of these, one was a nonsense change, three were missense changes, two were synonymous codon changes and two were changes in non coding sequences. These included Arg46Stop and Thr353Ile mutations that have previously been reported in POAG individuals. However all the sequence alterations identified have been found previously in normal Chinese subjects. Conclusions: The results of this study do not support a role for MYOC mutations in the pathogenesis of chronic primary angle closure glaucoma in the Chinese.

Keywords: genetics • anterior chamber • optic disc