i think you’re being a bit dramatic lol. To the extent that it is a grammatical error, it’s incredibly minor and doesn’t affect the meaning of the question. If it was asking for a specific mutation, it would ask something like “what mutation is associated with MODY?” (see nID 1474340669130)
But anyways, I wouldn’t mind changing it to either of those suggestions (i.e., y/n as a hint, or changing stem to “ARE GK gene mutations associated…”)
I definitely don’t think a comma is needed nor do I think it’s a run-on sentence. Just to make sure I’m not crazy I checked ChatGPT 
ChatGPT is not always accurate and if you have used it couple of times you would know that, sometimes you can give it the same questions and it gives you two different answers, not to mention that it sometimes gets mixed up in the wording of medical terms. But do as you wish, I guess I will just suspend the card.