MYOC mutation frequency in primary open-angle glaucoma patients from Western Switzerland.

PURPOSE: To determine MYOC gene mutation frequency in patients with primary open-angle glaucoma (POAG) from Western Switzerland.

METHODS

A total of 117 unselected index patients with primary open-angle glaucoma were submitted to a full eye examination. DNA was extracted from blood and PCR amplicons of MYOC exon 3 were screened for mutations by single-strand conformation polymorphism (SSCP) analysis. Abnormal conformers were analyzed both by direct bidirectional sequencing and by enzymatic mutation detection (EMD) assay.

RESULTS

Ten occurrences of four different sequence changes were detected, including: 1) five times the same disease-causing mutation (Q368X) in five unrelated POAG patients and 2) three distinct polymorphisms in five patients. The patients carrying an MYOC mutant allele were characterized by a broad clinical variability in terms of age of onset (34-77 years) and highest intraocular pressure (IOP) values (23-47 mmHg).

CONCLUSIONS

A pathogenic MYOC mutation (Q368X) was identified in 4.27% (5/117) of the studied population from Western Switzerland, which corresponds to the highest frequency yet reported for this mutation.