Dr. William Nyhan is currently Professor of Pediatrics at UCSD School of Medicine in La Jolla, Ca.  He has held appointments at University of Miami School of Medicine, Johns Hopkins University School of Medicine and has served on numerous pediatric advisory boards, advisory committees and research foundations.  A lifetime of interests and 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 the identification of Lesch-Nyhan syndrome.  Dr. Nyhan has studied the neuropathology of propionic acidemia including the manifestation of basal ganglia infarction and the neurologic non-metabolic presentation of PA.  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.  Current research includes evaluating the use of dichloroacetate (DCA) in treating a broad range of patients with mitochondrial disease leading to lactic acidemia.