Yes, you can deduct medical expenses for you son.
In general you can deduct medical expenses for yourself, your spouse, your dependent or for an individual who would have been your dependent except that:
- He or she received gross income of $4,050 or more in
2016,
- He or she filed a joint return for 2016, or
- You, or your spouse if filing jointly, could be claimed
as a dependent on someone else's 2016 return.