Introduction: Skeletal abnormalities are known to be a characteristic feature of the trisomy 8 syndrome, and radiological malformations are often more characteristic than the clinical features.
Case presentation: We report a mentally retarded male known to have mosaic trisomy 8 syndrome who presented with radial deviation of his right wrist. Radiographs showed an open ulna epiphysis with a closed radial epiphysis. Surgery was postponed until an older age as his ulna epiphysis had not yet closed, but clinical correction was achieved with a wrist brace.
Conclusion: This is the first report of radial deviation of the wrist in a patient with mosaic trisomy 8.