Although our control population did not include patients with other severe febrile illnesses, the levels of SDC1 in patients with severe plasma leakage in our study were several fold higher than in most other published studies of shock (20); this may provide a plausible explanation for why patients with dengue shock appear to experience a more marked plasma leakage than those with haemorrhagic and septic shock. The gene discussed is SDC1; the disease is dengue disease.