Study on MYOC/TIGR gene mutations in primary open-angle glaucoma

Abstract

To study the mutations in the trabecular meshwork induced-glucocorticoid response protein gene (TIGR/MYOC) in Chinese POAG patients. It was a case-control study. One hundred and eighteen Chinese patients with POAG and 150 control subjects without POAG were screened for coding sequence of the MYOC gene by polymerase chain reaction, single-strand conformation polymorphism (SSCP) and DNA sequence. Restriction endonuclease analysis was used to detect the SSCP in 150 gender- and aged-matched controls. Statistical significance of the difference in frequencies of MYOC mutations between POAG patients and the controls was determined by the chi-squared test. Three coding sequence variants that lead to amino acid changes were identified in MYOC gene. One mutation of MYOC gene was novel, I288M, which was present in one patient with POAG and 3 control subjects. G12R and Y353I have been reported previously. I288M and Y353I were found in both the subjects with and without POAG, the difference of the frequency of these two mutations between POAG and the controls was χ(2) = 0.07, P = 0.791 and χ(2) = 0.56, P = 0.453, respectively. Coding sequence mutations of MYOC were found in 4.23% POAG patients. Frequency of G12R mutation in POAG patients was significantly greater than that in the controls (χ(2) = 4.37, P = 0.037). One novel variant locus in the MYOC/TIGR (I288M) was found in the present study, but this mutation is not associated with POAG. G12R is the most common mutation in MYOC locus in Chinese subjects with POAG. Approximately 4.23% sporadic POAG patients have mutation in the exon 1 in MYOC/TIGR.