The glucocorticoid receptor N363S polymorphism and steroid response in Duchenne dystrophy

Background: Steroid administration is beneficial in Duchenne muscular dystrophy (DMD), but the response, incidence, and the severity of side effects are variable. Aims: To investigate whether glucocorticoid receptor (GRL) gene polymorphisms may be responsible for glucocorticoid sensitivity in DMD. Methods: Forty eight DMD patients treated either with prednisone or deflazacort were subjected to genetic analyses of the GRL gene. Results: Mutation studies revealed an heterozygous A to G mutation at GRL cDNA position 1220 in three DMD patients resulting in an asparagine to serine amino acid change at amino acid position 363 (N363S). The N363S carrier DMD patients showed a trend towards a later age at loss of ambulation in comparison with non-carrier patients. Conclusions: These data suggest that the N363S GRL polymorphism may be implicated in the long term response to glucocorticoids.