According to WHO handbook on severe malaria, severe falciparum malaria is defined as a patient with parasitological confirmed malaria who has one or more of the following clinical features: impaired consciousness; prostration; more than two convulsive episodes within 24 h; metabolic acidosis; acute pulmonary oedema and acute respiratory distress syndrome; circulatory collapse or shock (systolic blood pressure <80 mm Hg in adults & < 50 mmHg in children); severe anaemia (Hb <5gm/dl or haematocrit <15), renal impairment; jaundice and abnormal bleeding. Here, GSTM1 is linked to malaria.