Furthermore, homocysteine levels during the acute event appear to be similar in patients with NA-AION who are positive or negative for the C677T MTHFR mutation, which leads to elevated homocysteine levels (12), and a similar frequency of the MTHFR mutation was reported in patients with NA-AION and the general population (12). The gene discussed is MTHFR; the disease is anterior ischemic optic neuropathy.