A GLC1A gene Gln368Stop mutation in a patient with normal-tension open-angle glaucoma

Purpose: To present a case involving a patient with normal-tension glaucoma with a Gln368Stop mutation of the myocilin/trabecular meshwork inducible g lucocorticoid response protein (MYOC/TIGR) gene. Methods: Slit-lamp biomicroscopic and gonioscopic examination, morphometry of the optic disc, 24-hour intraocular pressure (IOP) profile, and perimetr y were performed to determine the phenotype of the patient. Neurologic exam ination and a computed tomographic (CT) scan of the brain were performed to rule out a neurologic disorder, Single-strand confirmation polymorphism (S SCP) analysis and subsequent sequence analysis of blood was performed for g enotyping of the GLC1A gene. Results: A nonsense codon, namely a Gln368Stop mutation in the third exon o f the GLC1A gene, was found in this patient with normal-tension glaucoma. Conclusion: In contrast to previous reports, a Gln368Stop mutation of the G LC1A gene need not be confined to patients with glaucomatous optic atrophy due to high IOP. The pathogenesis of glaucoma associated with GLC1A gene mu tations might be more complex than expected, and (unknown) suppressor mecha nisms have to be considered.