My DD is 3.5 and has always walked on her tippy toes. We see a physio and podiatrist and she has special exercises to do each day to stretch her calf muscles as walking on tippy toes can shorten them. She also wears an insert in her shoes which is stiff so it's harder for her to get up on her toes. She's much better now than she used to be - it's seems to be a habit for DD rather than a spectrum indicator, although she has speech delay so we are part of the early intervention program and see a speech pathologist as well. We were referred to the early intervention program by our child health nurse but you could go through your gp as well. Good luck!