Incidence of amyotrophic lateral sclerosis in the Faroe Islands

Objective – The establishment of variations in the incidence of
amyotrophic lateral sclerosis (ALS) in the Faroese population from
that found in other general populations may point to risk factors for
the development of this disease among the Faroese. The aim of this
study was to estimate the annual incidence of ALS during the period
1987–2009 and to compare the occurrence of ALS in the Faroe Islands
with data from three European countries. Method – All Faroese
patients diagnosed with ALS in this period are documented in the
current longitudinal prospective study. Result – The incidence of ALS
in the Faroe Islands during the period 1987–2009 is 2.6 (1.7–3.7) per
100,000 annually. The results yielded no strong evidence of a difference
(P = 0.09) in the incidence of ALS between Faroe Islands and Europe.
The sample population is small, and this, of course, impacts the
statistical precision of the findings. Conclusion – The data clearly
suggest, however, that the Faroese population is probably not subject
to an increased risk of ALS, even though certain risk factors are
present in the general population: (i) a fish-based diet contaminated
with mercury and polychlorinated biphenyl; (ii) the high occurrence of
the recessive carnitine transporter genetic defect; and (iii) the
anticipated high degree of inbreeding at the fifth generation.