G71.1Non-Billable (Header)Myotonic disordersChild CodesG71.11Myotonic muscular dystrophyHCC 197G71.12Myotonia congenitaG71.13Myotonic chondrodystrophyG71.14Drug induced myotoniaG71.19Other specified myotonic disordersCode Hierarchy└G71Primary disorders of muscles└G71.1Myotonic disorders└G71.1Myotonic disorders