A common founder for amyotrophic lateral sclerosis type 8 (ALS8) in the Brazilian population.
The P56S mutation in the VAPB gene causes ALS8. Eight families, comprising more than 1,500 individuals of whom about 200 are affected, are now known to carry this mutation. Seven are of Portuguese-Brazilian ancestry and one of African-Brazilian ancestry. Haplotype analysis shows a common founder for all families regardless of ancestry, with a founding event 23 generations ago (95% CI 13-39), consistent with the Portuguese colonization of Brazil.