The Genetic Characteristics in South Korean Patients With Primary Congenital Glaucoma

Study of Gene, Inheritance Pattern and Genotype - Phenotype Correlations in South Korean Patients With Primary Congenital Glaucoma

Primary congenital glaucoma, which presents at birth or in infancy, if left untreated, may threaten vision. The incidence of congenital glaucoma varies among different geographic locations and ethnic groups.

Three genetic loci for primary congenital glaucoma (GLC3A in 2p21, GLC3B in 1p36, GLC3C in 14q24.3) were identified. CYP1B1 (cytochrome P450 1B1 ) gene, in the GLC3A locus is the main known gene and different CYP1B1 mutations has been described.

The genetic characteristics in south Korean patients with primary congenital glaucoma have not been reported yet and the genotype-phenotype correlations, the prognosis and the genetic counseling have not also been established. This study represents the first repot about the rate of CYP1B1 mutations, the genotype-phenotype correlations in south Korean patients with primary congenital glaucoma.

Patients with primary congenital glaucoma and their family will be analyzed for CYP1B1 mutations by direct sequencing of polymerase chain reaction fragments. Primary congenital glaucoma will be diagnosed according to the clinical parameters by glaucoma specialists. Patients were classified to several groups according to the pattern of mutations. Clinical parameters and genotype correlation will be compared between groups

The incidence of congenital glaucoma varies among different geographic locations and ethnic group. The incidence of primary congenital glaucoma is supposed to be 0.01-0.03% in Western countries but it is reported higher in the Middle East. The inheritance pattern for congenital glaucoma is most commonly autosomal recessive. But the fact that sex distribution is unequal and the reduced penetration is seen in patients with family history implies that it's inheritance pattern is unclear. Approximately 10-40% patients have family background and the rate of penetration is known to about 10-40%.

Linkage studies have been genetic heterogeneity and have mapped three loci for primary congenital glaucoma (GLC3A in 2p21, GLC3B in 1p36, GLC3C in 14q24.3). Molecular screening of the gene or primary congenital glaucoma families liked to the 2p21 locus has determined that mutations in the cytochrome P450 1B1 (CYP1B1)are responsible for phenotype.

The genetic characteristics in south Korean patients with primary congenital glaucoma have not been not reported yet and the genotype-phenotype correlations, prognosis, genetic counseling have not established. So In this study, we evaluate the rate of CYP1B1 mutations in south Korean patients with primary congenital glaucoma and establish genotype-phenotype correlations.

Patients with primary congenital glaucoma and their family will be analyzed for CYP1B1 mutations by direct sequencing of polymerase chain reaction fragments. 100 ethnically matched normal individuals served as control subjects. Primary congenital glaucoma will be determined by examinations with slit lamp biomicroscopy, gonioscopy, measurement of intraocular pressure, corneal diameter and axial length, optic disc evaluation by glaucoma specialists. Patients were classified to several groups according to the pattern of mutations. Clinical parameters and genotype correlation will be compared between groups.

Inclusion Criteria:

• Clinical diagnosis of primary congenital glaucoma
• Candidate for peripheral blood sampling

Exclusion Criteria:

• Congenital glaucoma which relates with other systemic disease