Gene therapy for inborn errors of immunity: current clinical progress.

Hematopoietic stem cell transplant has been the single curative treatment for inborn errors of immunity (IEI) and is recommended for the most severe IEI conditions, such as severe combined immunodeficiency (SCID). However, adverse outcomes primarily due to histocompatibility differences between the donor and the patient are still of concern. Progress in genetic and molecular mechanisms, as well as new technology to insert DNA sequences in cell genomes has allowed the development of strategies to treat genetic diseases by correcting the gene defect in patients' cells.