Forty unrelated Mexican patients with Duchenne/Becker muscular dystrophy were analyzed for intragenic DMD gene deletions, using the multiplex amplification of 15 deletion-prone exons described by Chamberlain et al. and Beggs et al. The percentage of deletions was 52.5%, and the majority of them (86.3%) were located at the hot spot deletion region which encompasses exons 44-55. This frequency is higher than that found in American and European populations. There were no correlations between deletion size, location and clinical severity.