My son just turned 14 yrs old and was diagnosed with DMD at age 3. At the time of his diagnosis both his doctor and us agreed not to give him steroid because of his another diagnosis which is Autism. After all this years his current doctor suggested to put him on steroid even at this age. He said it may or may not help but may be good thing to consider. my son uses power chair since age 9. Anybody out there started steroid late and would like to share your experience please?