Genetic analysis of patients with primary congenital glaucoma

To determine the common gene mutation in patients with primary congenital glaucoma (PCG) in the Southeast region of Turkey via genetic analysis and to evaluate whether there were other gene mutations in these patients.

A total of 25 patients with PCG were included in this study. We performed sequence analysis including all exons of cytochrome p450 1B1 (CYP1B1), myocilin (MYOC), forkhead box C1 (FOXC1), and paired-like homeodomain 2 (PITX2) genes of the obtained samples. Further, we analyzed the results using the Nextgen analysis program.

The CYP1B1 gene mutation was detected in 20 (80%) of 25 patients, and FOXC1 gene mutation was detected in one (4%) patient. The mutation site of nine (45%) of the 20 CYP1B1 genes was found in the second exon. The pathogenic variant (p.Gly61Glu) was observed in 12 (60%) patients (in the first and second exons); the mutation type of six (50%) of these patients was homozygous. The mutation site of one patient with FOXC1 gene mutation was found to be in the first exon; its pathogenic variant was p.Met400lle. The mutation type in this gene was observed to be heterozygous. Lastly, there were no mutations in the MYOC, FOXC1, and PITX2 genes in combination with the CYP1B1 gene mutation.

The most common cause of PCG in our region is the CYP1B1 gene mutation, and the most frequent pathogenic variant is c.182G > A (p.Gly61Glu). We also determined that the CYP1B1 gene mutation was alone and did not occur with other gene mutations (MYOC, FOXC1, and PITX2).