title: Sporadic amyotrophic lateral sclerosis as an infectious disease: a possible role of cyanobacteria?
abstract: The available epidemiological data for amyotrophic lateral sclerosis (ALS) support an infectious etiology and lead us to propose a new hypothesis. We examined older epidemiological data concerning categories of the population with increased incidence (aged people, people living in rural areas, farmers, breeders), more recent epidemiological reports regarding Italian soccer players, AIDS patients, people living in highly polluted areas, and reports of cases of conjugal and pregnancy-associated ALS. The toxic and infectious hypotheses lead us to suggest a role for cyanobacteria in the production of endogenous beta-N-methylamino-L-alanine. Infection from a cyanobacterium, or another ubiquitous bacterium having similar characteristics, may be the missing clue to the etiology of ALS. We speculate that ubiquitous bacteria secreting toxic amino acids and "colonizing" tissues and organs in the human body might be the common element linking motor neuron diseases in Guam to sporadic ALS in the rest of the world.
authors.affiliation: Dipartimento di Scienze Neurologiche e Psichiatriche, Università degli Studi di Firenze, and Neurofisiopatologia-Unità Spinale, Azienda Ospedaliero Universitaria Careggi, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Stipa
authors.forename: Rosanna
authors.initials: R
authors.lastname: Taiuti
authors.forename: Giuseppe
authors.initials: G
authors.lastname: de Scisciolo
authors.forename: Graziano
authors.initials: G
authors.lastname: Arnetoli
authors.forename: Mario R
authors.initials: MR
authors.lastname: Tredici
authors.forename: Natascia
authors.initials: N
authors.lastname: Biondi
authors.forename: Laura
authors.initials: L
authors.lastname: Barsanti
authors.forename: Francesco
authors.initials: F
authors.lastname: Lolli
mesh_terms: D000599:Amino Acids, Diamino / Q000378:metabolism; D000690:Amyotrophic Lateral Sclerosis / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology; D003141:Communicable Diseases / Q000382:microbiology* / Q000473:pathology; D000458:Cyanobacteria / Q000378:metabolism / Q000502:physiology*; D000087522:Cyanobacteria Toxins; D006801:Humans; D015994:Incidence; D008954:Models, Biological; D044382:Population Groups / Q000145:classification
chemical_list: D000599:Amino Acids, Diamino; D000087522:Cyanobacteria Toxins; C001824:beta-N-methylamino-L-alanine