scheuemann's disease AND weight lifting

My son suffers from Scheuermann's disease He is 15 years old and he was very active in various sports, so I don’t understand how it happened. He was diagnosed only three days ago, and I don’t understand his condition yet. He wants to continue going into a gym for weight lifts, but I forbidden him. Now he is mad on me.

Scheuermann's disease is a disorder which primarily affects the adolescent thoracic spine. It produces pain and cosmetic deformity. The cause of this condition is unknown, so I doubt that some sport caused it. However, recent studies have implicated spinal end-plate fractures during the adolescent growth period as a likely causative factor. The average age at onset is between 13-17 years of age. I am not sure if weight lifting is safe for him or not, you should ask his doctor that, but I think that is best for him not to do anything for now.