<prompt> Answer this question truthfullyWhat specific HLA mutation would make Abacavir ABC contraindicated for HIV treatment?  <response>: <reason> Abacavir ABC is contraindicated for HIV treatment if the patient has an HLA B5701 mutation. This mutation is associated with an increased risk of hypersensitivity reactions to Abacavir, which can be severe and life-threatening. Therefore, it is important to screen patients for this mutation before prescribing Abacavir. 