Beginning of Essay
In research facilities all around the world scientist are attempting to stop diseases at their very roots. Instead of trying to find drugs to cure illnesses they are trying to change the genes that cause the diseases. The process by which this is done is called ....

Middle of Essay
.... defective ADA gene. Possession of a normal gene leads to the continuous, regular production of ADA in cells throughout the body. Without at least one properly functioning gene, children have no way of converting deoxyadenosine (a waste product) into inosine. This leads to the rapid build-up of deoxyadenosine in the system, which becomes phosphorlyzed into a toxic triphosphate, which kills T-cells. The result is an almost complete failure of the immune system and early death. Previous treatment options included bone marrow transplants, which worked well with matched donors. A major breakthrough occurred with the development of polyethylene glycol coa ....