Sample: Urine 24 hrs (Specimen colletion)
Schedule: Once a week
Units: nmol/mmol Creatinine
Range: See Table
HVA is the major final metabolite of the dopamine pathway whereas VMA is the major final metabolite of the norepinephrine pathway (See Catecholamines and Metanephrines). Both HVA and VMA are often excreted in excess amounts by neuroblastomas, ganglioneuroblastomas, pheochromocytomas, and in Riley-Day syndrome. Excretion may be intermittent. Plasma HVA is increased in schizotypal personality disorders. Approximately 20% of subjects with neuroblastoma do not have increased VMA.