Mutation analysis of the genes associated with anterior segment dysgenesis, microcornea and microphthalmia in 257 patients with glaucoma

Genetic factors have an important role in the development of glaucoma; however, the exact genetic defects remain to be identified in the majority of patients. Glaucoma is frequently observed in patients with anterior segment dysgenesis (ASD), microcornea or microphthalmia. The present study aimed to detect the potential mutations in the genes associated with ASD, microcornea and microphthalmia in 257 patients with glaucoma. Variants in 43 of the 46 genes, which are associated with ASD, microcornea or microphthalmia, were available in whole-exome sequencing. Candidate variants in the 43 genes were selected following multi-step bioinformatic analysis and were subsequently confirmed by Sanger sequencing. Confirmed variants were further validated by segregation analysis and analysis of controls. Overall, 70 candidate variants were selected from whole-exome sequencing, of which 53 (75.7%) were confirmed by Sanger sequencing. In total, 27 of the 53 were considered potentially pathogenic based on bioinformatic analysis and analysis of controls. Of the 27, 6 were identified in BEST1, 4 in EYA1, 3 in GDF6, 2 in BMP4, 2 in CRYBA4, 2 in HCCS, and 1 in each of CRYAA, CRYGC, CRYGD, COL4A1, FOXC1, GJA8, PITX2 and SHH. The 27 variants were detected in 28 of 257 (10.9%) patients, including 11 of 125 patients with primary open-angle glaucoma and 17 of 132 patients with primary angle-closure glaucoma. Variants in these genes may be a potential risk factor for primary glaucoma. Careful clinical observation and analysis of additional patients in different populations are expected to further these findings.