Research (cont.)

Types of Disorder gene therapy can and cannot treat

can: Hemophilia,Cancer, Parkinson's disease (*), Huntington's disease*, Sickle cell anemia*
cannot: Multifactorial genetic disorders(**)

(*)Gene therapy has also been studied as a possible treatment for Parkinson's disease, a degenerative nervous system disease. Researchers have recently figured out a way to transfer genes into the brain. Viruses cannot be used as vectors because they are too big to make it across the protective membrane that separates circulating blood from brain cells (called the blood-brain barrier). So, instead of using viral vectors, researchers have used fat molecules (called liposomes) that are coated in a polymer, called polyethylene glycol (PEG), to deliver the new genes. This allows billions of copies of a gene to be inserted into the brain to calm overactive connections in the brain. Researchers are hopeful that this method may be an effective treatment for Parkinson's disease in the future

(**) Most disorders, including Alzheimer's disease and arthritis, occur when there are mutations or problems with multiple genes. These types of disorders are especially difficult to treat with gene therapy because doctors would have to correct all of the mutated genes.

http://www.naturalstandard.com/demo/demo-gp-genetherapy.asp

Explanation on what ADA-deficient SCID is

Refer to previous blog post

How gene therapy can be used to treat ADA-deficient SCID 

Gene therapy for ADA-deficient SCID could be performed by introducing a normal copy of the human ADA gene into the blood forming stem cells of the patient's bone marrow by using a new type of gene delivery system (in this trial called a lentiviral vector). The gene corrected cells are then transplanted back into the patient after small dose of chemotherapy. These gene corrected stem cells can survive into the body and make lymphocytes.