Statement 1 is Correct: Genetic medicines (such as gene therapy and gene editing) treat or prevent diseases at their root cause. They work by introducing, removing, or changing genetic material to correct or compensate for faulty or missing genes responsible for a disease.

Statement 2 is Correct: Genetic material cannot simply be injected into the body; it requires a carrier, or "vector," to successfully penetrate target cells. Engineered viruses (like adeno-associated viruses or lentiviruses) are genetically modified to remove their disease-causing properties and are widely used to deliver therapeutic genes. Lipid nanoparticles (LNPs) are highly effective non-viral vectors that encapsulate the genetic payload (such as mRNA or CRISPR-Cas9 tools) in a protective fat layer to safely deliver it into cells.

Statement 3 is Incorrect: Genetic medicines do not alter the entire DNA sequence. The human genome contains approximately 3 billion base pairs and over 20,000 genes. Gene therapies are highly precise, targeting only specific localized sequences or single genes (e.g., replacing one defective gene or making a targeted cut) while leaving the vast majority of the patient's native DNA completely unchanged.

Therefore, the correct option is C.