A sequence change (Arg158Gln) in the leucine zipper-like motif region of the MYOC/TIGR protein

The myocilin/trabecular meshwork-inducible glucocorticoid response (MYOC/TI GR) gene was identified as a gene that caused open angle glaucoma (OAG). Si ngle strand conformation polymorphism analysis and subsequent sequence anal ysis were performed for the MYOC/ TIGR gene in 120 unrelated Japanese OAG p atients with increased intraocular pressure (IOP), 116 unrelated OAG patien ts without increased IOP, and 106 unrelated control subjects without glauco ma. An Arg158Gln sequence change in the leucine zipper-like motif (LZM) reg ion in the myosin-homology domain was found in 2 OAG patients with or witho ut increased IOP, and in a 56-year-old control subject without glaucoma. Th is is the first report of missense sequence change in the LZM region of the MYOC/TIGR protein in subjects showing various phenotypes, including a cont rol subject. These findings suggest that Arg158Gln in the LZM region is pro bably a rare nondisease-causing polymorphism, despite its important role in this region, because it was found in a control subject, although Arg158Gln was previously reported as a probable disease-causing mutation.