Primary congenital glaucoma: three case reports on novel mutations and combinations of mutations in the GLC3A (CYP1B1) gene.

PURPOSE: To describe three patients with congenital glaucoma homozygous and compound heterozygous for different mutations and benign sequence variants in the cytochrome P 450 1B1 (CYP1B1) gene. METHODS: All patients were examined by slit-lamp biomicroscopy, gonioscopy, measurement of the cornea and optic disc, ultrasound biometry, and automated static threshold perimetry when possible. Direct sequence analysis was performed on DNA extracted from peripheral blood from the patients and their parents. RESULTS: For patient 1, a newborn boy with buphthalmos and an opaque cornea, a novel homozygous C/T transition in codon 355 (CGA>TGA) led to a predicted nonsense codon Arg355X truncating the protein by 188 amino acids. For patient 2, a 24-year-old man, a compound heterozygous mutation 1410-1422del/1546-1555dup was found. For patient 3, a 34-year-old man, two novel heterozygous missense mutations resulting in an Ala443Gly and a Glu229Lys amino acid exchange and five benign sequence variants were found. CONCLUSION: Our results confirm the crucial role of CYP1B1 mutations for congenital glaucoma.

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 glucocorticoid response protein (MYOC/TIGR) gene. METHODS: Slit-lamp biomicroscopic and gonioscopic examination, morphometry of the optic disc, 24-hour intraocular pressure (IOP) profile, and perimetry were performed to determine the phenotype of the patient. Neurologic examination and a computed tomographic (CT) scan of the brain were performed to rule out a neurologic disorder. Single-strand confirmation polymorphism (SSCP) analysis and subsequent sequence analysis of blood was performed for genotyping of the GLC1A gene. RESULTS: A nonsense codon, namely a Gln368Stop mutation in the third exon of the GLC1A gene, was found in this patient with normal-tension glaucoma. CONCLUSION: In contrast to previous reports, a Gln368Stop mutation of the GLC1A gene need not be confined to patients with glaucomatous optic atrophy due to high IOP. The pathogenesis of glaucoma associated with GLC1A gene mutations might be more complex than expected, and (unknown) suppressor mechanisms have to be considered.

Juvenile open angle glaucoma: fine mapping of the TIGR gene to 1q24.3-q25.2 and mutation analysis.

Autosomal dominant juvenile open angle glaucoma (JOAG) is an early-onset form of primary open angle glaucoma (POAG), which has been linked to chromosome 1q21-q31. Recently, mutations in the trabecular meshwork inducible glucocorticoid response gene (TIGR), one of the candidate genes mapped in this region, were identified in glaucoma patients of several families. We screened for mutations of the TIGR gene in two German families with JOAG and in 100 unselected sporadic cases of POAG. In the first family we identified a Pro370Leu mutation and in the second family a Gly367Arg mutation cosegregating with the glaucoma phenotype. No pathogenic mutation was found in 100 sporadic cases but a Tyr347Tyr polymorphism was found in two patients. Furthermore, fluorescence in situ hybridization (FISH) analysis was used to map a TIGR-specific yeast artificial chromosome to 1q24.3-q25.2.