Phenotype and Genotype Correlation in Iranian Primary Congenital Glaucoma Patients

To explore the correlation between clinical manifestations of primary congenital glaucoma (PCG) and CYP1B1 mutations.

A clinical and molecular genetic study was performed on a cohort of 17 patients with PCG and known CYP1B1 mutation profile including 10 subjects with and 7 cases without mutations. Ophthalmolgical records were reviewed and phenotype which was defined by age at onset, presenting intraocular pressure (IOP), corneal diameter, and vertical cup to disc ratio, and the number of procedures was correlated with the presence or absence of CYP1B1 mutations.

Overall, 8 mutations were identified in 10 patients. The disease became manifest earlier than 1 month of age in 9 of 10 (90%) cases with, as compared with 2 of 7 (28.6%) patients without mutations (P=0.035). Baseline IOP was 29.3±6.5 mm Hg in the mutation-positive group versus 17.6±3.7 mm Hg in subjects without mutations (P<0.001). Patients with mutations also had significantly higher IOP throughout follow-up (P<0.002). The number of operations was significantly higher in subjects with mutations (3.3±1.8 vs. 1.8±1.5 procedures, P=0.025). Six patients (60%) with mutations were female as compared with 1 subject (14.3%) in the nonmutation group (P=0.134). There was no significant difference between the study groups in terms of corneal diameter (P=0.475) and vertical cup to disc ratio (P=0.794).

PCG patients with CYP1B1 mutations seem to have earlier onset disease, display more severe manifestations, and require more operations as compared with subjects without such mutations. These findings may have implications in prognosticating the disease and genetic counseling.