More than 80% of rare diseases are single-gene genetic disorders and lack of effective treatments. Gene therapy can alter the biology of living cells by modifying or manipulating gene expression, offering the possibility of correcting underlying genetic defects to address the underlying cause of rare diseases. With the development of genetic diagnostics for rare diseases, advances in vector delivery technologies and biotechnologies such as CRISPR-Cas9, gene therapy has become one of the key research directions for therapeutic drugs for rare diseases.