Overview of Amino Acid and Organic Acid Metabolism Disorders By Matt Demczko, MD, Mitochondrial Medicine, Children's Hospital of Philadelphia Reviewed / Revised Oct 2021 | Modified Sep 2022 View Patient Education More Information Topic Resources Beta-Amino Acid and Gamma-Amino... Gamma-Glutamyl Cycle Disorders Glycine Metabolism Disorders Histidine Metabolism Disorders Lysine Metabolism Disorders Proline and Hydroxyproline... Miscellaneous Amino Acid... The kidneys actively reabsorb significant amounts of amino acids.