Analysis of MYOC gene mutation in a Chinese glaucoma family with primary open-angle glaucoma and primary congenital glaucoma

BACKGROUND: Glaucoma is one of the leading causes of blindness in the world. Primary open-angle glaucoma (POAG) and primary congenital glaucoma (PCG) are subtypes of glaucoma. Myocillin is the first gene identified to be involved in POAG. Recently, myocillin mutation has been found in PCG. In this context, we reported a special glaucoma pedigree, which was composed of both PCG and POAG patients, and analyzed the mutation of myocillin in this pedigree. METHODS: The family was composed of the parents, a son and a daughter. All members of the family underwent the complete ophthalmologic examinations. All coding exons 1 - 3 and flanking introns of myocilin gene were screened for sequence alterations by polymerase chain reaction and direct DNA sequencing. RESULTS: The son was the proband, who was diagnosed as PCG in both eyes. The father was diagnosed as POAG in the right eye, the left eye was still normal. Both the sister and the mother of the proband had normal intraocular pressure without glaucomatous optic disc changes. The mutations in intron 2 of myocilin gene were detected in the family. While the proband and the father were homozygous, the mother and the sister were heterozygous for the mutation. CONCLUSIONS: Homozygous mutation in intron 2 of myocilin gene is involved in both POAG and PCG. It is suggested that the pathogenesis might be overlapping in POAG and PCG.