The Diagnostic Value of Utrophin in Mild Dystrophinopathy (Becker Muscular Dystrophy)

Becker Muscular Dystrophy (BMD) is a subtype of dystrophinopathies and designated as “mild form of dystrophinopathy”. The frequency rate of the disease is 1:18000 to 1:30000 in different populations and the symptoms are presented at about 5-6 years of age. The diagnostic panel composed of Serum Ceratin Kinase (SCK) measurement, Electromyography (EMG), and as a major component, muscle biopsy and immunohistochemistry for dystrophines; finally the results should be confirmed by Western blot (WB) analysis, which is a sensitive method for protein detection. The aim of this study was using utrophin, an autosomal homologue for dystrophin, which is upregulated in dystrophinopathies, parallel to WB in order to evaluate its diagnostic value. In this case-control study, fifteen clinically suspected cases of BMD were examined from 2006 to 2008. After muscle biopsy and dystrophin IHC, the muscle samples were immunostained for utrophin and the tissue extract were analyzed for protein components. In all of the cases, the results revealed partial staining for utrophin in the sarcolemma and pale or distorted band of dystrophin in WBA. Utrophin immunostain could be considered as an important component of BMD diagnostic panel and may be substituted for WBA, which is an expensive and time-consuming method.