Orthostatic intolerance (ORSTI) is a rare genetic syndrome (<1/1000000) (Orphanet 2024) that affects the cardiovascular and respiratory systems and increases the risk of potentially life-threatening heart problems. The patients manifest with adrenergic symptoms such as lightheadedness, dizziness, blurred vision, palpitations, and tachycardia (increase by at least 30 beats per minute) following an assumed upright posture, in the absence of orthostatic hypotension (Jacob et al. 1997). Altered mentation, near-syncope, syncope with transient cognitive impairment, dyspnea, easy fatigability, and anxiety may also occur (Boudoulas et al. 1980). Most patients with ORSTI are women between the ages of 20 and 50 years (Low et al. 1995). The consistent presence of these traits across generations suggests a strong genetic basis. The missense of the solute carrier family 6, member-2 (SLC6A2) gene, has been discovered to play a key role in ORSTI (Shannon et al. 2000).