ABSTRACT
A ‘‘dystrophic’’ pattern of findings on muscle biopsy (characterized by variation in fiber size, the presence of degenerating and regenerating muscle fibers, and an increase in fibrous connective tissue) is common to all forms of muscular dystrophy. While the clinical presentation or family history may suggest or confirm the diagnosis of Duchenne muscular dystrophy (DMD) or Becker muscular dystrophy (BMD), in some patients it is not possible to differentiate these conditions from other forms of limb girdle muscular dystrophy (LGMD) solely on the basis of clinical findings. This is particularly true for sporadic or isolated cases within a family, in whom the differential diagnosis of DMD from sarcoglycanopathy, or BMD from other classes of LGMD, may be impossible based on clinical examination alone. There are currently at least 19 identified disease candidates for the LGMD, and several more yet unidentified disease loci (1-3).
