No sex difference in mutations rates of Duchenne muscular dystrophy.

Segregation analysis was performed to evaluate possible differences in mutation rates in man. It was based on 514 males with Duchenne type muscular dystrophy (DMD) from five of nineteen hospitals for muscular disease in Japan. The estimated proportion of sporadic cases (new mutations) was 0.29 +/- 0.046, which is in excellent agreement with the expected 0.333 if there is no sex difference in mutation rates. The rate of mutation was estimated to be 6.3 X 10(-5) per generation. The incidence and prevalence rates among males were estimated to be 217 X 10(-6) and 49.9 X 10(-6), respectively.