"While there are a lot of people who get unusual abilities from an x-gene, there are plenty of people who have unusual abilities who get them from somewhere else. The obvious historical example being Steven Rogers, whose enhanced strength and endurance came from an injection."
"Well… Yes, I understand that unusual abilities can come from a variety of sources. But I'm afraid that my specialty is genetics and, specifically, the x-gene."
"I understand that. But really, what's the difference? How would you help a mutant with control issues?"
"I would.. study how their ability functioned…" I hear a quiet but amused exhalation. "Yes, I understand your point. I would have to at least start in the same place with anyone who manifested unusual abilities, and identifying for certain whether a person with special abilities had the x-gene or not would take months. But I do want you to understand that some issues experienced by mutants aren't comparable to people whose abilities come from other sources."