Genome Editing for Fertility: Unlocking the Promise of CRISPR/Cas9 in Addressing Male Infertility - A Narrative Review.

Male infertility remains a significant global reproductive health challenge, frequently attributed to genetic mutations impairing spermatogenesis and sperm function. This narrative review aims to explore the genetic and molecular underpinnings of male infertility and evaluate the emerging role of Clustered Regularly Interspaced Short Palindromic Repeats-CRISPR-associated protein 9 (CRISPR/Cas9) genome editing as a diagnostic and therapeutic tool, while addressing its associated ethical, technical, and safety considerations. A Comprehensive literature search was conducted across PubMed, Scopus, Web of Science databases, covering studies published between September 1992 and April 2025. Keywords included "male infertility," "genetic causes of male infertility," "genome editing," "CRISPR/Cas9 and male infertility," "genome editing in male reproduction," "ethical concerns of CRISPR," and "future fertility treatments." Eligible studies focused on genetic correction strategies, spermatogonial stem cell applications, off-target effects, mosaicism, and ethical implications of gene editing. The review synthesizes current knowledge on genetic and epigenetic etiologies of male infertility. It discusses the therapeutic potential of CRISPR/Cas9 in correcting these defects and restoring fertility in preclinical models. Critical challenges, including off-target gene editing, germline mosaicism, long-term safety, and ethical debates surrounding human germline modification, were examined. The review also considers future advancements in genome editing and artificial sperm development. CRISPR/Cas9 represents a transformative platform in reproductive medicine with promising implications for treatment of genetically linked male infertility. However, its clinical translation demands rigorous validation, transparent ethical deliberation, and robust regulatory frameworks. Future innovations combining genome editing, regenerative biology, and precision diagnostics may revolutionize fertility care, but must proceed with caution to ensure safety, efficacy, and ethical integrity.