Effects of genetic counseling on Duchenne muscular dystrophy families in Brazil.

We report the preliminary results of a follow-up study of 574 females at-risk for Duchenne dystrophy, recontacted 3 to 13 yr after genetic counseling (GC). Among them, 290 are younger than 18 yr or still unmarried. The effectiveness of GC (reproductive performance) in the remaining group is analyzed in terms of procreation, rate of sterilization, and mean number of children. The observed data suggest that females at-risk involved in GC had about 169 children less than their normal, nonaffected brothers. In terms of prevention this would correspond roughly to 42 Duchenne affected boys and 42 carrier girls.