We performed a 1-year longitudinal study of Six Minute Walk Test (6MWT), North Star Ambulatory Assessment (NSAA), and timed function tests in Becker muscular dystrophy (BMD). Skeletal muscle dystrophin was quantified by immunoblot. We grouped deletions ending on exon 45 ("del 45-x", n = 28) or 51 ("del x-51", n = 10); isolated exon 48 deletion ("del 48", n = 10); and other mutations (n = 21). O...
