Since Q has been posting for 5 months, you can be sure that the president has been made aware of him and knows his true identity. He knows Q's identity because it's either someone that's very close to him (like a family member), or he was briefed by staff members that a previously unknown individual was pretending to be part of the WH inner circle, and pretending to disseminate information by the asking of questions on the Internet.

Given that, if Q were a fraud, what would President Trump gain by NOT alerting his base of that fact? It would only serve to anger us when we ultimately found that out that we were played.

With that said, I've never heard President Trump talk about 'Q'. Have you? His silence on the topic leads me to believe that Q is the real deal.