Duchenne and Becker muscular dystrophies: an Estonian experience.

The clinical and molecular features of 25 Duchenne (DMD), two intermediate (D/BMD) and three Becker (BMD) muscular dystrophy patients from 26 unrelated families were evaluated. Early psychomotor development was normal in patients with D/BMD and BMD. Learning to walk independently after 15 months of age was a risk sign of DMD in nine (36%) patients. Abnormality in crawling was seen in 13 (54%) patients with DMD. These boys demonstrated initial symptoms earlier than those who learned to crawl normally. Mental retardation was established in five (20%) patients with DMD. Deletions in the dystrophin gene were found in 11 families (48%). They were accumulated (9/11, 82%) in the distal region of the gene.