Mutation Detection in - and -Sarcoglycan (LGMD2E and LGMD2C)

Direct mutation analysis in the genes for β- and γ- sarcoglycan (SG) is performed in a patient in whom a type of autosomal recessive limb-girdle muscular dystrophy (LGMD) affecting the SG complex is suspected. Ideally, this suspicion should have been substantiated by analysis of the SG complex using immunohistochemical (IHC) methods and/or Westernblot analysis of a muscle biopsy specimen from the patient before proceeding to the actual mutation analysis (see Chapter 15 ). In addition, the IHC results may directly suggest the primary SG gene involved (see subheading), thus potentially streamlining the search for the underlying mutation, which otherwise may have to cover all four currently known SG genes.