Occurrence of beta-methylamino-l-alanine (BMAA) in ALS/PDC patients from Guam

Acta Neurol Scand. 2004 Oct;110(4):267-9. doi: 10.1111/j.1600-0404.2004.00320.x.


We tested the brain tissues of the Chamorro people of Guam who died of amyotrophic lateral sclerosis/Parkinsonism dimentia complex (ALS/PDC) for the neurotoxin beta-methylamino-l-alanine (BMAA). We used validated high-pressure liquid chromatography and liquid chromatography-mass spectrometry analyses to test well-characterized archival tissues of the superior frontal gyrus from eight Chamorros from Guam and a comparison group of 15 Canadians. BMAA was found as a free amino acid in 83% of Chamorro ALS/PDC patients (3-10 microg/g) as a protein-associated amino acid in 100% of the Chamorro individuals (149-1190 microg/g). Both forms of BMAA were also found at comparable levels in two Canadians who died of progressive neurodegenerative disease. BMAA, which is produced by cyanobacteria, may be associated with some cases of neurodegenerative disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Amino Acids, Diamino / analysis*
  • Amyotrophic Lateral Sclerosis / etiology
  • Amyotrophic Lateral Sclerosis / metabolism*
  • Bacterial Toxins / analysis*
  • Case-Control Studies
  • Dementia / etiology
  • Dementia / metabolism*
  • Female
  • Frontal Lobe / chemistry
  • Guam
  • Humans
  • Male
  • Marine Toxins / analysis*
  • Microcystins
  • Middle Aged
  • Neurotoxins / analysis*
  • Parkinsonian Disorders / etiology
  • Parkinsonian Disorders / metabolism*


  • Amino Acids, Diamino
  • Bacterial Toxins
  • Marine Toxins
  • Microcystins
  • Neurotoxins
  • cyanobacterial toxin
  • beta-N-methylamino-L-alanine