Gene therapy: Recent advances, future directions and concerns

There is now convincing experimental evidence which suggests that gene therapy, a procedure to correct inherited disorders by molecular techniques, may become a clinical reality in the near future. The modes of gene delivery to appropriate target cells and tissues are now more specific. Of the viral and nonviral methods of gene transfer, adenovirus based vectors have produced the best clinical results. Successful gene therapy trials which have recently taken place on some selected genetic disorders, indicate that the somatic gene manipulation as shown by the long-term stable expression of the transferred genes, will be more practical and a safer approach for the time being. This is compared to germ-line therapy which involves insertion of gene into gamete forming cells in such a way that the disorders in the offspring would also be corrected. Despite all this optimism there are still many difficulties to overcome, particularly the isolation of genes and their regulatory function. Ethical and religious considerations of gene therapy are also very important as both irrational and rational fears are associated with deliberate genetic manipulation. These will dissipate eventually, once reasonable success in gene manipulation is achieved.