Prevalence of congenital myopathies in a representative pediatric united states population.

The prevalence of congenital myopathies in the United States has not been examined. To address this, we determined the point prevalence of congenital myopathies in a well-defined pediatric population from Southeastern Michigan. The overall point prevalence was 1:26,000. Mutations in RYR1 were the most common cause of congenital myopathies at 1:90,000. Our data broadly agrees with estimates from previous European studies and provides the first estimate of the prevalence of congenital myopathies in the United States. Ann Neurol 2011;70:662-665.