The term "muscular dystrophy" (MD) describes a group of primary genetic
disorders of muscle that often have a distinctive and recognizable
clinical p- notype, accompanied by characteristic, but frequently not
pathognomonic, pathological features. Research into the molecular basis
of the MDs by a c- bination of positional cloning and candidate gene
analysis has provided the basis for a reclassification of these
disorders, with genetic and protein data augmenting traditional
clinically based nomenclature. These findings have brought insights into
the molecular pathogenesis of MD, with an increasing number of potential
pathways involved in arriving at a dystrophic phenotype. Some common
themes can be recognized, however, including the involvement of five
members of the dystrophin-associated complex (dystrophin and four
sarcoglycans) in different types of MD, and the involvement of two
nuclear envelope proteins in producing an Emery-Dreifuss MD phenotype.
Other d- ease-associated genes appear to cause MD in a completely
unrelated way, such as the involvement of calpain 3 in a form of
limb-girdle muscular dystrophy. Section 1 of Muscular Dystrophy: Methods
and Protocols reviews tra- tional strategies used to identify MDs.
Meantime, techniques developed as a result of the research strategies
described previously have become an integral part of the management of
many patients with MD and their families, and these techniques are
addressed in Sections 2 (DNA-based tests) and 3 (p- tein-based
analyses). The continued effort to translate this enhanced und- standing
into a molecular cure or treatment for MD is reviewed in Section 4.
