Six Month Study of Gentamicin in Duchenne Muscular Dystrophy With Stop Codons

Inclusion Criteria: * Age 5-20 years * Duchenne muscular dystrophy documented by written report of stop codon mutation analysis of the dystrophin gene. * Subject is capable of cooperating for efficacy and safety testing * Absent dystrophin on muscle biopsy * Subjects may be untreated, taking prednisone or comparable corticosteroids * Subjects taking corticosteroids must be on the same dose for at least 3 months (90 days) prior to the start of the study. Exclusion Criteria: * Known allergy to any aminoglycoside or sulfate compounds * Current use of potential nephrotoxic or ototoxic drug * Current use of corticosteroids has not been stable for 3 months (90) days * Known mutation at nucleotide 1555 in 12S rRNA gene of mitochondrial DNA (predisposes to aminoglycoside hearing loss and commercially available via Athena Diagnostics Lab). This DNA testing (Hearing susceptibility test) will be made available through funding from this grant. * Inability to hear within the range of 0 to 25 dB in any hearing frequency by pure tone audiometry * Cystatin C equal to or \> 1.4mg/L * Other medical condition that would impede the conduct of study (e.g., congestive heart failure)