The CRISPR-Cas9 Technology Used for the Treatment of Single-Gene Genetic Diseases

Genetic diseases pose a threat to global health. Diseases caused by single gene mutations, such as sickle cell anemia (SCA), cystic fibrosis, and hemophilia B, are particularly prominent. CRISPR-Cas9, as a revolutionary gene editing technology, provides a new path for the cure of genetic diseases by targeting and repairing pathogenic gene mutations. Current research has advanced from in vitro cell experiments to the clinical trial stage. The cure rate of hematopoietic stem cell editing for SCA has reached 85%; the lung function repair of cystic fibrosis is achieved through AAV vector delivery; the in vivo editing of hemophilia B restores the coagulation factor activity to over 30%. However, the technology still faces core challenges such as off-target effects, low delivery efficiency, and ethical controversies. This article systematically analyzes the application mechanism, clinical progress, and optimization strategies of CRISPR-Cas9 in the treatment of three single-gene genetic diseases, confirming that it can achieve disease cure through precise targeting repair, and proposes optimized schemes for high-fidelity enzymes and non-viral delivery systems. The significance of this research lies in providing theoretical basis for individualized treatment of genetic diseases, promoting clinical translation, and focusing on long-term safety verification, reversible editing technology development, and the construction of inclusive medical models in the future to break through technical bottlenecks and balance ethical conflicts.