Primary open angle glaucoma may be inherited as a Mendelian trait, as in the case of causative mutations in genes such as the myocilin (MYOC), optineurin (OPTN), and TANK-binding kinase 1 (TBK1) (26, 27), where other genes or environmental factors play little role (See below). The gene discussed is MYOC; the disease is open-angle glaucoma.