title: Detection of cyanobacterial neurotoxin β-N-methylamino-l-alanine within shellfish in the diet of an ALS patient in Florida.
abstract: Cyanobacteria produce the neurotoxic amino acid β-N-methylamino-l-alanine (BMAA), which in contaminated marine waters has been found to accumulate in shellfish. Exposure to BMAA has been associated with an increased risk of neurodegenerative disease. Analysis of blinded samples found BMAA to be present in neuroproteins of individuals who died from ALS and ALS/PDC, but generally not in the brains of patients who died of causes unrelated to neurodegeneration or Huntington's disease, an autosomal dominant neurodegenerative disease. We here report support for a link between a patient with ALS and chronic exposure to the cyanobacterial neurotoxin BMAA via shellfish consumption. The patient had frequently eaten lobsters collected in Florida Bay for approximately 30 years. LC-MS/MS analysis of two lobsters which this ALS patient had placed in his freezer revealed BMAA at concentrations of 27 and 4 μg/g, respectively, as well as the presence of 2,4-diaminobutyric acid (DAB), a BMAA isomer. Two additional lobsters recently collected from Florida Bay also contained the neurotoxins BMAA and DAB. These data suggest that invertebrates collected in water where cyanobacterial blooms are present, if consumed, may result in direct human exposure to these neurotoxic amino acids. The data support the assertion that prolonged exposure to BMAA may have played a role in the etiology of ALS in this patient.
authors.affiliation: Institute for Ethnomedicine, Box 3464, Jackson Hole, WY 83001, USA. Electronic address: sandra@ethnomedicine.org.
authors.forename: Sandra Anne
authors.initials: SA
authors.lastname: Banack
authors.affiliation: Institute for Ethnomedicine, Box 3464, Jackson Hole, WY 83001, USA. Electronic address: james@ethnomedicine.org.
authors.forename: James S
authors.initials: JS
authors.lastname: Metcalf
authors.affiliation: Department of Neurology, Miller School of Medicine, University of Miami, Miami, FL, USA. Electronic address: WBradley@med.miami.edu.
authors.forename: Walter G
authors.initials: WG
authors.lastname: Bradley
authors.affiliation: Institute for Ethnomedicine, Box 3464, Jackson Hole, WY 83001, USA. Electronic address: paul@ethnomedicine.org.
authors.forename: Paul Alan
authors.initials: PA
authors.lastname: Cox
mesh_terms: D000328:Adult; D000599:Amino Acids, Diamino / Q000032:analysis* / Q000633:toxicity; D000690:Amyotrophic Lateral Sclerosis / Q000139:chemically induced / Q000503:physiopathology*; D000458:Cyanobacteria / Q000737:chemistry*; D000087522:Cyanobacteria Toxins; D005431:Florida; D006801:Humans; D057230:Limit of Detection; D008297:Male; D008875:Middle Aged; D009498:Neurotoxins / Q000032:analysis* / Q000633:toxicity; D012758:Shellfish / Q000032:analysis*; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry
chemical_list: D000599:Amino Acids, Diamino; D000087522:Cyanobacteria Toxins; D009498:Neurotoxins; C001824:beta-N-methylamino-L-alanine
keywords: 2,4-Diaminobutyric acid; Amyotrophic lateral sclerosis; BMAA; Cyanobacteria; Neurotoxins in Florida Bay; South Florida