Hematological abnormalities were common among patients with leptospirosis, including thrombocytopenia (85%; platelets <100,000 cells/mm3), hematuria (71%), and anemia (62%; male: Hb<13.8 g/dL, female: Hb<12.1 g/dL). The gene discussed is GSTM1; the disease is leptospirosis.