Correlation between electroretinogram findings and molecular analysis in the Duchenne muscular dystrophy phenotype

Fifteen consecutive patients with the Duchenne muscular dystrophy (DMD) phenotype were studied. Each patient was asked to undergo an ophthalmic examination, an electroretinogram (ERG), and to donate a blood sample for molecular diagnosis. All 15 patients had a normal ophthalmic examination. Electroretinography was successful in 14/15 patients. The ERG tracings were normal in seven patients, abnormal in seven, and unreliable in one. Blood for molecular analysis was obtained in 12/15 patients. In the seven patients with a normal ERG, five underwent molecular analysis, and in these five no deletion was detected in the dystrophin gene. In the seven patients with an abnormal ERG, six had molecular analysis available, and all six were found to have a deletion. These results suggest that patients with a classic DMD phenotype are genetically heterogeneous, and that this heterogeneity is reflected in the ERG.