It must be over the last 15+ years or so we have been inundated by SuperHero TV series and films from the US (post 911?). In it people are imbued with Superhuman powers that go well beyond that which seem physical possible and yet are given a pseudo scientific explanation of genetic mutation in such franchises as Marvels films based on the X-men, Mutant X and Marvel Agents of shield.
Of course super hero stories are really fantasy but can you still create a more plausible and internally consistent plot that refers to science without making a complete pigs ears of it? In the? TV series 'Marvels Agents of Shield' which is part of the same story arc as the Iron Man, Avengers and Thor film series (Hulk? Agent Carter?) emergence of powered people, specifically the inhuman (oddly pejorative title) were descendant of human modified by an extraterrestrial alien race called the Kree intended as weapons (an awful lot of super powers look like weapons). Their powers were dormant until activate by a diviner – a blue crystal, that killed normal humans.

The problem with this is that a single gene by itself does not seem enough to code for an elaborate and specific power. A whole chromosome? The human body, anything like the power effects, has not the energy, not the resilience to survive the forces, masses and power requirements. So, an alternative pseudo science is required. What if the mutant gene gives the user access to a separate power machine perhaps via wormhole or another dimension. Not so different from the ancient gene access the the ancients technology in US-Canadian TV series Star Gate: Atlantis. The machine reads the mind of the user to enable control of the power, verifies the 'access' Krell gene, selects the type of power, protects the user's body(mainly) from the power used e.g. temperature, high electrical current, force, physical transformation etc. This sounds very similar to the Krell machine in the 1956 US film 'The forbidden Planet'.