title: Methylmalonic and malonic aciduria in a dog with progressive encephalomyelopathy.
abstract: A 12 week old female Labrador retriever dog with signs of progressive diffuse degeneration of the brain and spinal cord was found to have methylmalonic and malonic aciduria. Over a 5 month period, the dog developed neurologic signs compatible with disease of the central nervous system with predominant diffuse cerebral and right lateralizing brainstem deficits. Gross pathological examination of the brain showed that the lateral, third, and fourth ventricles of the brain were markedly enlarged and associated with white and grey matter atrophy. Syringomyelia and hydromyelia of the central canal into the dorsal funiculus of the spinal cord beginning at the level of the cervical intumescence and extending to the lumbar intumescence was also present. Significant biochemical abnormalities include methylmalonic and malonic aciduria, mild lactic and pyruvic aciduria. There was also accumulation of citric acid cycle intermediates including succinic, aconitic, and fumaric acids. Disordered fatty acid oxidation was suggested by increased excretion of adipic, ethylmalonic, suberic and sebacic acids. Neither ketoacidosis nor hyperammonemia were present, and serum cobalamin levels were normal. Overall, this dog demonstrates an inborn error of metabolism resulting in abnormal organic acid accumulation associated with a neurodegenerative disease.
authors.affiliation: Department of Veterinary Clinical Sciences, Ohio State University, Columbus 43210, USA.
authors.forename: M
authors.initials: M
authors.lastname: Podell
authors.forename: G D
authors.initials: GD
authors.lastname: Shelton
authors.forename: W L
authors.initials: WL
authors.lastname: Nyhan
authors.forename: S O
authors.initials: SO
authors.lastname: Wagner
authors.forename: A
authors.initials: A
authors.lastname: Genders
authors.forename: M
authors.initials: M
authors.lastname: Oglesbee
authors.forename: W R
authors.initials: WR
authors.lastname: Fenner
mesh_terms: D000818:Animals; D001921:Brain / Q000473:pathology / Q000648:ultrastructure; D004283:Dog Diseases / Q000473:pathology* / Q000652:urine*; D004285:Dogs; D004576:Electromyography; D004679:Encephalomyelitis / Q000473:pathology / Q000652:urine* / Q000662:veterinary*; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006849:Hydrocephalus / Q000378:metabolism / Q000473:pathology; D008314:Malonates / Q000652:urine*; D008661:Metabolism, Inborn Errors / Q000473:pathology / Q000652:urine* / Q000662:veterinary*; D008764:Methylmalonic Acid / Q000652:urine*; D009132:Muscles / Q000294:innervation / Q000473:pathology / Q000648:ultrastructure; D009412:Nerve Fibers / Q000648:ultrastructure
chemical_list: D008314:Malonates; D008764:Methylmalonic Acid; C030290:malonic acid