Detection of cyanobacterial neurotoxin β-N-methylamino-l-alanine within shellfish in the diet of an ALS patient in Florida

• Published in: Toxicon (Oxford) Vol. 90; pp. 167 - 173
• Main Authors: Banack, Sandra Anne, Metcalf, James S., Bradley, Walter G., Cox, Paul Alan
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.11.2014
• Subjects: 2,4-Diaminobutyric acid; Adult; Amino Acids, Diamino - analysis; Amino Acids, Diamino - toxicity; Amyotrophic lateral sclerosis; Amyotrophic Lateral Sclerosis - chemically induced; Amyotrophic Lateral Sclerosis - physiopathology; BMAA; Cyanobacteria; Cyanobacteria - chemistry; Florida; Homarus americanus; Humans; Limit of Detection; Male; Middle Aged; Neurotoxins - analysis; Neurotoxins - toxicity; Neurotoxins in Florida Bay; Shellfish - analysis; South Florida; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry; Florida; ASW, USA, Florida; ASW, USA, Florida, Florida Bay; 2,4-Diaminobutyric acid; South Florida; Amyotrophic lateral sclerosis; BMAA; Cyanobacteria; Neurotoxins in Florida Bay
• ISSN: 0041-0101; 1879-3150
• DOI: 10.1016/j.toxicon.2014.07.018

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. •β-N-methylamino-l-alanine (BMAA) is present in lobsters from Florida Bay.•A patient caught and ate lobsters regularly for 30 years before being diagnosed with ALS.•Direct human exposure to neurotoxins is possible through shellfish collected in areas where cyanobacterial blooms are present.•Further studies are needed on chronic low-dose exposure to BMAA as prolonged exposure may play a role in ALS etiology.