At high altitude, neuro-hormonal (Nitric oxide, vascular endothelial growth factor (VEGF), free radicals and cytokines) and hemodynamic responses result in cerebral vasodilatation causing intracranial hypertension leading to capillary leakage causing vasogenic brain edema due to movement of fluid and protein out of vascular compartment. The gene discussed is VEGFA; the disease is intracranial hypertension.