High incidence of amyotrophic lateral sclerosis in the Faroe Islands 2010-2020.

The Faroese population isolate harbors epidemiological and genetic characteristics that likely differ from outbred populations. This population-based register study found that the Faroese 2010-2020 crude incidence of amyotrophic lateral sclerosis (ALS) was 4.9/100,000 person-years (95% confidence interval [CI], 3.3-7.0) and the age- and sex-standardized incidence (US 2010 Census Population) was 4.1/100,000 person-years (95% CI, 2.7-6.0), which is a 68% increase from the 1987-2009 estimate. The 2020 crude prevalence was 9.5/100,000 (95% CI, 3.0-19.6) in a population of 52,912 inhabitants. Incidence and prevalence estimates of ALS in the Faroes are high and further research is warranted to uncover the genetic or environmental determinants of ALS in this population.

Amyotrophic lateral sclerosis in the Faroe Islands - a genealogical study.

In the Faroe Islands, a clustering of amyotrophic lateral sclerosis (ALS) was observed on the geographically isolated island, Suðuroy. This study aims to estimate the frequency of familial ALS (fALS) in the Faroes including 43 patients diagnosed with ALS. Patients with fALS were identified through medical records and the Faroese Multi Generation Register. Firstly, fALS was recognized when occurring between first- or second-degree relatives. Secondly, families and individuals with fALS were recognized through pedigrees (≥3 cases within 3 generations). The prevalence of ALS was 3 times higher in Suðuroy compared to the nationwide prevalence. The frequency of fALS was at least 14% (n = 6) and mean survival time was 1.7 years shorter for fALS compared to sporatic ALS (p = 0.01. SD = 0.5, range 1.0-2.2). This study is suggestive of familial clustering in excess of expected for ALS and supports a genetic contribution to ALS in the Faroe Islands albeit environmental exposure within families cannot be excluded.

Multiple sclerosis: variation of incidence of onset over time in the Faroe Islands.

Epidemiological studies of multiple sclerosis (MS) conducted in the Faroe Islands identified 10 annual incidences per 100,000 in 1945 and 4.5 in the period 1986-2007. The aim of this study was to estimate the annual incidence of onset of MS in the Faroe Islands in the six decades from 1943 to 2002 and during the period 2003-7.All patients diagnosed with MS between 1943 and 2007 were documented. The incidence of MS before 1943 was around 0.2 per 100,000 annually. During the period 1943-62, an annual incidence rate of 4.4 [confidence interval (CI) 2.9-6.1] per 100,000 was observed. During the 20-year period 1963-82, the level declined significantly (p < 0.001) to around 0.6 (0.3-1.5). Thereafter, an increase was seen during the period 1983-2002, evidencing a significant (p < 0.001) sevenfold increase in the annual incidence to 4.6 (3.2-6.2) per 100,000. Subsequently, for the period 2003-7, there was again a decline to 2.4 (2.1-3.3) (p = 0.003). This study confirms that significant variation in the incidence of MS has occurred in the Faroes over time. Because the rate of genetic change within the Faroese population is relatively slow, the study suggests environmental factors as a contributing cause of MS. If only genetic factors for susceptibility were important, the incidence rate should not wax and wane over time, as is observed.

Multiple sclerosis incidence in the Faroe Islands 1986-2007.

OBJECTIVE: Epidemiological studies of the isolated Faroese population in 1945 identified a high annual incidence of multiple sclerosis (MS) of 10/100,000. At the time, there was speculation that the disease was brought to the country by British occupation forces resident in the islands from 1940 to 1945. The objective of the current study is to determine the incidence of diagnosis of MS in the Faroe Islands during the period 1986-2007. METHODS: All patients in the Faroe Islands diagnosed with MS from July 1, 1986 to July 1, 2007 are documented in the current longitudinal, prospective study. The diagnosis is based on clinical observation, magnetic resonance imaging scanning, cerebrospinal fluid tests, and visual evoked potential response testing. RESULTS: The incidence of MS during the period 1986-2007 is 4.5/100,000 annually. This is generally of the same order of magnitude as other research findings in Scandinavia and Iceland. The incidence of MS from 1986 to 2007 is about double the incidence in the Faroe Islands for the period from 1940 to 1986, calculated to be 2.7/100,000 annually. CONCLUSION: The observed incidence of MS in the Faroe Islands, where the population is genetically homogeneous and where the diet exposes the population to neuro-toxic contamination, is at the same level as found in other high-risk regions. The former detected epidemics of MS in Faroe Islands seems apparently to have leveled out and could not be recognized in the recent period covered by the present survey.