Becker muscular dystrophy (BMD) is a rare X-linked recessive inherited disorder, due to an in-frame mutation in dystrophin gene and results in a progressive decline in muscle functions when left untreated.

Deflazacort is a synthetic corticosteroid characterized by insertion of a fused methyloxazolidine ring in the structure of prednisone. Deflazacort has been used in DMD but not so far in BMD. MicroRNAs (miRNAs) are small non-coding RNA molecules approximately 22 nucleotides in length. A group of miRNAs is highly expressed in skeletal and cardiac muscle and they are called myomiRs. The myomiR family includes miR-1, miR-133a, miR-133b, miR-206 which are used as non-invasive serum biomarkers in neuromuscular diseases.

In a preliminary trial we have used deflazacort (60 mg/ alternate day) in BMD patients and have monitored their weight, MRC, spirometry, and echocardiography and as biomarkers, serum microRNA versus untreated BMD and control. We have compared results of myomiRNAs in 2 deflazacort treated BMD cases versus 3 untreated BMD patients.

Deflazacort was beneficial in treating the two patients by modulating the inflammatory response in muscle stabilizing their clinical condition and functional outcomes and a spirometric data. Cardiac ejection fraction was 55-60 %. There was no effect on their weight and only a slight decrease the bone densitometry. These data highlight the potential use of miRNA as biomarkers of BMD that seem to correlate with both clinical and MRI imaging changes.