Investigation on genetic heterogeneity in Duchenne muscular dystrophy.

The preliminary results of a study to investigate possible genetic heterogeneity in Duchenne muscular dystrophy (DMD) are reported. Ninety-eight patients have been analyzed: 47 were isolated cases; 51 were familial cases. The patients were divided into three groups (normal intelligence, borderline, and mentally retarded) according to mental capacity and a comparison of clinical evolution (onset of clinical signs and loss of ambulation) as well as serum enzyme activities (creatine-kinase and pyruvate-kinase). In addition intrafamilial correlation analysis was done for the same parameters. The preliminary results did not show a significant difference between DMD patients with normal intelligence and those with mental retardation.