Gene therapy has been successful in curing Codes genetic diseases in laboratory animals through

• exposure to X-ray to rectify the defective gene

• replacing the defective gene with a functional gene

• oral delivery of genes

• use of therapeutic medicines to rectify the defective gene

B.

replacing the defective gene with a functional gene

Gene therapy is a collection of methods that allows correction of a gene defect that has been diagnosed in a child or embryo. Here, genes are inserted into a person's cells and tissues to treat a disease. Correction of a genetic defect involves delivery of a normal (functional) gene into the individual or embryo to take over the function of and compensate for the non-functional gene.