CRISPR-Cas gene editing enables precise, programmable DNA modifications for therapeutic applications. Derived from bacterial immune systems, this technology is being applied to treat genetic blood disorders, cancers, metabolic diseases, and viral infections. Variants like Cas9, Cas12, Cas13, and CasX offer flexibility in targeting DNA and RNA. Innovations such as base editing, prime editing, and epigenome modulation further expand its clinical utility. Multiple biotech companies are advancing CRISPR-based therapies, with several candidates in preclinical and clinical trials. Approved treatments like CASGEVY™ for sickle cell disease exemplify its real-world potential.