[Study on the gene mutation of TIGR in primary open angle glaucoma, their relatives and normal controls in Chongqing].

Objective: To study trabecular meshwork induced glucocorticoid response protein (TIGR) gene mutation in primary open angle glaucoma (POAG), their relatives and normal controls in Chongqing.

Methods: (1) The coding sequence of TIGR was screened for sequence alterations using polymerase chain reaction (PCR) followed by single-strand conformation polymorphism (SSCP). (2) Samples corresponding to bands of altered mobility were sequenced. (3) The sequence alterations were analyzed by bioinformatics.

Results: (1) In 15 POAG, TIGR gene mutation was found in 5 cases. In 10 POAG relatives, 2 TIGR gene mutations were found. No TIGR gene mutation was found in 20 normal persons in Chongqing. (2) The mutation sites Ser55Thr, Asp247Stop and in 49021 c-t alteration discovered in the present study have not been reported previously. The 63155 c-t alternation has been reported as a polymorphism site previously. (3) Bioinformatics analysis indicated that the mutations in structural domain could lead to the changes in the amino acid sequence coded, second structure of protein, isoelectric point and antigen binding site.

Conclusions: We found that the TIGR gene mutations is closely related to the occurrence of JOAG in Chongqing. The relatives of POAG patients may have a higher incidence of TIGR gene mutation as compared with the controls. Furthermore, after analyzed by bioinformatics, we found that the alteration of structure and biological activity of TIGR protein resulted from gene mutation may be one of the important changes that leading to the occurrence of POAG.