A new comprehensive natural history study about Amish nemaline myopathy (ANM) in the Old Order Amish population focuses on the promise of gene therapy for this lethal disorder. Amish nemaline myopathy (ANM) is an infantile-onset muscle disease linked to a mutation of the TNNT1 gene. The study summarizes genealogical records, clinical data, and molecular reports of one hundred and six ANM patients born between 1923 and 2017.