Pheochromocytoma/paraganglioma Syndrome 1, also known as paragangliomas 1, is related to pheochromocytoma/paraganglioma syndrome 4 and persistent generalized lymphadenopathy, and has symptoms including aphonia An important gene associated with Pheochromocytoma/paraganglioma Syndrome 1 is SDHD (Succinate Dehydrogenase Complex Subunit D), and among its related pathways/superpathways are Metabolism and Respiratory electron transport, ATP synthesis by chemiosmotic coupling, and heat production by uncoupling proteins.. The drugs Phenoxybenzamine and Vasodilator Agents have been mentioned in the context of this disorder. Affiliated tissues include adrenal gland and thyroid, and related phenotypes are adrenal pheochromocytoma and extraadrenal pheochromocytoma