Muscular dystrophy classification and diagnosis has been transformed over the 13 or so years since the cloning of the dystrophin gene (involved in Duchenne and Becker muscular dystrophy). A child or adult presenting with a muscular dystrophy can now expect a precise diagnosis. Precision of diagnosis brings with it improved information for the patient and their family in terms of genetic counselling and prognostic advice. Unfortunately precision of diagnosis still fails to be matched by the availability of curative treatments, though a greater understanding of the various subtypes of muscular dystrophy does means that more specific management can be planned. The purpose of this annotation will be to address the various subtypes of muscular dystrophy encountered particularly in childhood within the context of diagnostic standards and related molecular information which enhance the investigation and management of individuals with muscular dystrophy.