Mutations in the gene for cytochrome P4501B1 (CYP1B1) were identified, and account for most cases of autosomal recessive congenital glaucoma, CYP1B1 could be the predominant cause of primary congenital glaucoma (PCG) in the Omani population (78%).[22, 23] Numerous cytogenetic reports indicate other chromosome regions that may harbor congenital glaucoma genes, and autosomal dominant forms of congenital glaucoma have been identified.[24] Mapping studies in eight families with congenital glaucoma have revealed a second locus, GLC3B, at 1p36.[25]. This evidence concerns the gene CYP1B1 and primary congenital glaucoma.