The aetiology of neurological complications of organic acidaemias--a role for the blood-brain barrier

J Inherit Metab Dis. 2006 Dec;29(6):701-4; discussion 705-6. doi: 10.1007/s10545-006-0415-8. Epub 2006 Oct 14.


The blood-brain barrier (BBB) metabolically isolates the central nervous system (CNS) from the circulation and protects it against fluctuations of hydrophilic nutrients in plasma and from intoxication. Recent studies have shown that dicarboxylic acids (DCAs) are transported across the blood-brain barrier at very low rates. In organic acidaemias, neurological complications are common. We hypothesize that, as a result of the very limited efflux, in certain organic acidaemias there is pathological accumulation of DCAs (e.g. glutarate, 3-hydroxyglutarate, D-2- and L-2-hydroxyglutarate, methylmalonate) in the brain secondary to the metabolic block. At high concentrations some of these compounds may become neurotoxic. Treatment should be aimed at preventing the accumulation of these compounds using our understanding of the properties of the BBB.

MeSH terms

  • Animals
  • Biological Transport
  • Blood-Brain Barrier*
  • Brain / pathology
  • Central Nervous System / pathology
  • Humans
  • Metabolism, Inborn Errors / complications*
  • Metabolism, Inborn Errors / diagnosis*
  • Nervous System Diseases / complications*
  • Organic Anion Transporters / metabolism*


  • Organic Anion Transporters