Biotechnology and Bioinformatics (1+1)

4.2.6. Gene therapy

A recent development in gene tic technology known as gene therapy focuses on curing inherited disorders. Researchers have replaced defective genes with normal alleles , inactivated a mutated gene, or inserted a normal form of a gene into a chromosome.

The earliest success in human gene therapy involved the treatment of infants who cannot produce adenosine deaminase (ADA), an enzyme important to normal function of the immune system. Scientists have successfully inserted the normal allele for the gene that codes for the enzyme into cells in ADA-deficient children. Preliminary evidence indicates that this gene therapy leads to better immune function in recipients. Researchers are also exploring gene therapy’s potential to help treat people with many other conditions, including certain cancers, hemophilia, heart disease, and cystic fibrosis.

Although the United States Food and Drug Administration (FDA) has approved more than 400 clinical trials in gene therapy, this method of treating disease remains far from an unqualified medical success. Treatments usually produce some improvement in the underlying condition, but not enough to consider the therapy suitable for large-scale use. The death of a patient involved in a gene therapy experiment in 1999 caused the National Institutes of Health (NIH), a federal agency that monitors gene therapy studies, to reevaluate the safety and effectiveness of gene therapy clinical trials.