Disease name: Werner syndrome, sometimes called "adult progeria"
Affected populations: Werner syndrome is estimated to affect 1 in 100,000 live births worldwide, though its prevalence varies among countries. In Japan, the syndrome affects an estimated 1 in 40,000 to 1 in 20,000 people, whereas the prevalence in the United States is around 1 in 200,000. This difference between locations is partly attributed to "founder effects" — instances where genetic variation declines after a small group of individuals gets separated from a larger population. This limits the gene pool and can cause disease-causing mutations to become more widespread within a population.
