Frequently Asked QuestionsWhatis gene therapy?

Some diseases are caused by errors (mutations) inspecific genes. Gene therapy delivers DNA into cells to replacemutated (bad) or missing genes or to add new, good genes.

Scientists are investigating a number of differentways to do this. Right now, gene therapy is only done through research studiescalled clinical trials. Unlike medicine, gene therapy directly addresses the underlyinggenetic problem, not just the symptoms.

Genes are in the nucleus of every living cell. A gene is an instruction manual for the body. Itgives the direction to make the proteins that make the body work.

A gene cannot be inserted directly into a cell.Instead, a carrier called a vector is genetically engineered to deliver thegene. Viruses are usually used as the vectors because they are very good atinfecting cells and inserting the gene(s) into the cells DNA. Types of viralvectors are retrovirus, adenovirus, adeno-associated virus and herpes simplexvirus.

No. The virus is specially engineered to remove the infectious piece. We only keep the part of the virus that is good at burrowinginto a cells nucleus. Once the virus delivers the gene into the cell, thevirus slips away.

It is not for all genetic diseases. It is only forsome diseases caused by a single gene mutation. Some diseases that might betreated with gene therapy are:

The goal is to cure a disease or make changes so thebody can better fight off disease. It does not correct 100% of your childs cells.Instead, every time a cell with the good gene reproduces, it carries a copyof the new healthy gene.

The vector can be injected or given by IV directlyinto a specific tissue. Or a sample of cells can be removed and exposed to thevector in a laboratory. The cells with the vector are then returned to thepatient.

1) Stem cells are collected in one of two ways: by bone marrow aspiration, or by purifying blood drawn through a central line in a process called apheresis.

2) Before the infusion, most children have chemotherapy. This makes room for the new cells by getting rid of the existing cells in the bone marrow.

3) In the laboratory, the stem cells from the blood or bone marrow are exposed to a virus or other type of vector containing the desired genes.

4) Once the stem cells take up the vector and merge the genes into cells DNA, the cells are given back to the patient in an IV infusion.

Bone marrow transplants usestem cells from another person (a donor). Gene therapy uses your childs owncells. Using your childs own cells is a benefit because there is no risk ofrejection, or graft vs. host disease, like there is with donor cells. Genetherapy is still only offered through clinical trials and at only a fewresearch hospitals and centers.

Gene therapy is still very new,and is mostly used to treat children who cannot be cured by standardtreatments. Gene therapy is not for everydisease or a good fit for every patient. Your childneeds to meet certain criteria for safety reasons. Your childs doctor willtalk to you about whether your child is a good fit for a gene therapy clinicaltrial.

Your child will have 410 daysof chemotherapy before the infusion. This is called chemotherapy conditioning.It clears out bone marrow to make room for the new stem cells. This has typicalside effects from chemotherapy, like nausea/vomiting, mouth sores and pain.

Your child has the transfusionon the Bone Marrow Transplant floor (6 West) at the Jimmy Fund Clinic. It is given one timeintravenously (through an IV), just like a blood transfusion. It takes 1530minutes. The amount of time your childwill stay in the hospital depends on many factors. Most children stay 46weeks.

Your child will have bloodtests to check for the vector in the cells, and to see how the cells are responding. Your child will come in forfollow-ups frequently. Your childs care team will talk to you about when youshould call your childs doctor. Always call with questions or concerns or ifyou notice signs of an infection.

Many research studies areunderway to test gene therapy as a safe treatment for a growing number ofdiseases. Improvements have already beenmade in safety. Early gene therapy trials showed a high risk of turning ononcogenes that cause cancer. Now, experts have retooled the vector to lower thelikelihood of turning on oncogenes.

Learn more

Read more from the original source:
Gene Therapy Questions | FAQs - Dana-Farber/Boston ...

Comments are closed.