Distal myopathies

Although muscle disease classically presents with proximal extremity weakness, some myopathic disorders, including several types of muscular dystrophy, result in predominantly, or exclusively, distal muscle involvement. Accurate diagnosis of these relatively uncommon conditions can be challenging for the clinician, because of both the unusual phenotype and the significant overlap in the clinical features of many of these entities. Advances in molecular genetics have permitted a tentative classification of these disorders and have led to the identification of the responsible gene lesion for several of these entities. This review summarizes current understanding of this interesting group of muscular dystrophies and briefly summarizes other myopathies that can present with distal weakness.