Mutations are traits specific to Mutants selected on Character Creation. After you create your character, you can spend 4 Mutation points to gain a random new mutation. They are split up into 5 Categories as follows:
You start with 12 mutation points to spend at character creation. To gain a new mutation, you need to allocate points to learn one. The costs vary between mutation and the more expensive ones are generally stronger than ones that cost less.
After character creation, you can spend 4 mutation points to gain a new, but random mutation you do not have already.
As you level up you gain mutation points. With them, you can upgrade certain mutations to make them stronger or have a higher chance of activating an effect. Mutations cost 1 point to upgrade.