Laboratory tests showed homocysteinemia (HCY) of 22.43 μmol/L, Hb of 98 g/L, mean corpuscular volume (MCV) of 108.1 fL, HCT of 30.50%, albumin of 37.1 g/L, total protein 52.1 g/L, and high neuron-specific enolase (NSE) level of 32.64 ng/mL, indicating hyperhomocysteinemia and macrocytic anemia. The gene discussed is GSTM1; the disease is macrocytic anemia.