My 13-year-old son, who was diagnosed with developmental coordination disorder and dysgraphia several years ago, taught himself to type a long time ago. He can type about 65 wpm. I think he is even faster at texting on his iPhone. He uses his iPhone for taking notes. He once used it to type out answers to essay questions and emailed them to his teacher at the end of class.
When he started piano lessons at age 5 his fingers were weak and that seemed to be his biggest problem. I think his teacher lets him change the fingering sometimes to make it easier for him. She also stopped having him do the workbook because writing in it and drawing notes without going over the lines was a problem for him.
