Objective To investigate the genetic basis of the pathogenesis of a Guangzhou (GZ 1) pedigree with primary open angle glaucoma (POAG) Methods DNA fragments of the trabecular meshwork inducible glucocorticoid response protein (TIGR) gene from 4 typical POAG patients and 2 normal subjects were amplified by polymerase chain reaction (PCR) The amplified PCR fragment was cloned into a pT Adv vector, and direct sequencing was carried out on an ABI 373 automated DNA sequencer using dye terminator chemistry to detect the mutation Results The TIGR gene mutation was identified in the selected subjects of this pedigree This mutation is a “C to T” transition at position 370, different from that of western countries and equivalent to the position change found in Japanese patients with familial POAG No mutation was found in the TIGR gene fragment in 2 normal subjects of the pedigree Conclusions These preliminary results provide insights into the pathogenesis of POAG by the TIGR gene mutation, and into the underlying action of the different mutations in oriental and western peoples Objective To investigate the genetic basis of the pathogenesis of a Guangzhou (GZ 1) pedigree with primary open angle glaucoma (POAG) Methods DNA fragments of the trabecular meshwork inducible glucocorticoid response protein (TIGR) gene from 4 typical POAG patients and 2 normal subjects were amplified by polymerase chain reaction (PCR) The amplified PCR fragment was cloned into a pT Adv vector, and direct sequencing was carried out on an ABI 373 automated DNA sequencer using dye terminator chemistry to detect the mutation Results The TIGR gene mutation was identified in the selected subjects of this pedigree This mutation is a “C to T” transition at position 370, different from that of western countries and equivalent to the position change found in Japanese patients with familial POAG No mutation was found in the TIGR gene fragment in 2 normal subjects of the pedigree Conclusions These preliminary results provide insights into the pathogenesis of POA G by the TIGR gene mutation, and into the underlying action of the different mutations in oriental and western peoples