AGC1 deficiency associated with global cerebral hypomyelination

N Engl J Med. 2009 Jul 30;361(5):489-95. doi: 10.1056/NEJMoa0900591.


The mitochondrial aspartate-glutamate carrier isoform 1 (AGC1), specific to neurons and muscle, supplies aspartate to the cytosol and, as a component of the malate-aspartate shuttle, enables mitochondrial oxidation of cytosolic NADH, thought to be important in providing energy for neurons in the central nervous system. We describe AGC1 deficiency, a novel syndrome characterized by arrested psychomotor development, hypotonia, and seizures in a child with a homozygous missense mutation in the solute carrier family 25, member 12, gene SLC25A12, which encodes the AGC1 protein. Functional analysis of the mutant AGC1 protein showed abolished activity. The child had global hypomyelination in the cerebral hemispheres, suggesting that impaired efflux of aspartate from neuronal mitochondria prevents normal myelin formation.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Transport Systems, Acidic / deficiency*
  • Antiporters / deficiency*
  • Aspartic Acid / metabolism
  • Cerebrum / pathology*
  • Child, Preschool
  • Epilepsy / genetics*
  • Female
  • Hereditary Central Nervous System Demyelinating Diseases / genetics*
  • Homozygote
  • Humans
  • Magnetic Resonance Imaging
  • Mitochondria / metabolism
  • Mitochondrial Membrane Transport Proteins / genetics*
  • Muscle Hypotonia / genetics
  • Mutation, Missense*
  • Protein Isoforms
  • Psychomotor Disorders / genetics*
  • Sequence Analysis, DNA
  • Syndrome


  • Amino Acid Transport Systems, Acidic
  • Antiporters
  • Mitochondrial Membrane Transport Proteins
  • Protein Isoforms
  • SLC25A12 protein, human
  • aspartate-glutamate carrier
  • Aspartic Acid