Here the hypothesis that abnormal norepinephrine transporter (NET) function might contribute to the pathophysiology in some patients with OI was tested.
In a patient with orthostatic intolerance and her relatives, we measured postural blood pressure, heart rate, plasma catecholamines, and systemic norepinephrine spillover and clearance, and we sequenced the norepinephrine-transporter gene and evaluated its function.
In a patient with orthostatic intolerance and her relatives, we measured postural blood pressure, heart rate, plasma catecholamines, and systemic norepinephrine spillover and clearance, and we sequenced the norepinephrine-transporter gene and evaluated its function.
It has been proposed that a mutation in exon 9 of the norepinephrine transporter gene (Ala457Pro), resulting in more than 98% loss of function compared with the wild type, might provide a pathogenetic mechanism to explain the clinical symptoms of patients with OI.