My 10 year old son was diagnosed five years ago with congenital adrenal hyperplasia.  At this time his bones have advanced to the point where he is beginning puberty.  Our options were a shot to stop it or letrozole which will inhibit estrogen production which, at the end of puberty, fuses the bone plates.  Has anyone else tried this?  I have searched the web and the only articles I find about this drug pertain to the treatment of breast cancer.  Our doctor mentioned arguments about fertility.  Does anybody have more information about this drug such as side effects, long term effects, etc?