Dr. William Leo Nyhan, MD PhD (born March 13, 1926) currently holds the position of Professor of Pediatrics at UC San Diego School of Medicine in La Jolla, CA. Previous work has been done at Johns Hopkins University School of Medicine, University of Miami School of Medicine, and in addition he has served on a number of advisory committees, pediatric advisory boards, and research foundations. Over 56 years of experience and interests in areas of research span a wide variety of disorders of amino acid metabolism, including 4-Hydroxybutyric aciduria, 3-methylglutaconyl-Co A hydratase deficiency, multiple carboxylase deficiency, methylmalonic acidemia, propionic acidemia, and also the identification of Lesch-Nyhan syndrome. He is currently involved in the ongoing development of tandem mass spectrometry for use in newborn screening and research, and is involved in identifying the cause(s) of progressive neurologic disability in MMA after liver transplantation. Dr. Nyhan has studied the neuropathology of propionic acidemia including the manifestation of basal ganglia infarction and the neurologic non-metabolic presentation of PA. Current research includes evaluating the use of dichloroacetate (DCA) in treating a broad range of patients with mitochondrial disease leading to lactic acidemia.