A synonym nucleotide substitution (c.4299G > T, p.Gly1433Gly), likely disrupting an ESE in exon 3127, caused mild dystrophinopathy (NSAA 34/34) in two brothers aged 35 and 47, with 10~30% dystrophin with slightly reduced molecular weight at immunoblot. This evidence concerns the gene DMD and neuromuscular disease caused by qualitative or quantitative defects of dystrophin.