Glossary of
Medical Terms
A list of key terms with patient-friendly definitions.

Sickle Cell Disease
Sickle cell is an inherited blood disorder that changes the shape of red blood cells, making it harder for them to carry oxygen through the body. This can cause pain, fatigue, and other health challenges throughout a person’s life.

Sickle Cell Trait
Sickle cell trait is not the disease but it occurs when an individual has inherited one sickle cell gene and has one unaffected beta globin gene.

Bone Marrow Transplant
A procedure in which bone marrow stem cells are collected from one individual (the donor) and given to another (the recipient). The stem cells can be collected either directly from the bone marrow or from the blood by a procedure called leukapheresis. Sometimes the patient serves as his or her own bone marrow stem cell donor.

Hematopoietic Stem Cell Transplantation:
Hematopoietic stem cell transplantation (HSCT) is a treatment that replaces unhealthy blood-forming cells with healthy ones through an IV infusion. The new cells help the body make normal blood and rebuild the immune system, offering a possible cure for diseases like sickle cell.

Gene Therapy
The stem cells are changed by altering part of the genes. Types of gene therapy include gene addition and gene editing. While each of these approaches introduces different types of gene-based changes, they start out the same: the stem cells are collected and taken to a lab for modification.

Chemotherapy
Drugs primarily used to destroy cancer cells but also used in bone marrow transplant patients without cancer in order to ensure successful engraftment. These drugs have side effects that affect other normal cells in the body. Another name commonly used is "chemo."

Total Body Irradiation
Treatment using radiation to kill cancer cells and/or prepare the body for transplant by destroying diseased cells and suppressing the recipient’s immune system’s ability to reject the donor cells.

Graft vs. Host Disease (GVHD)
A reaction between the transplanted T lymphocytes of the donor (graft) and the tissues/organs of the patient (host). The T- cells of the donor graft can attack the recipient's tissues. The skin, GI tract, liver and other organs can be affected.

Informed Consent
The process whereby a patient/parent/legal guardian is given information about a specific surgery or treatment (i.e., bone marrow transplant). All potential risks and benefits must be understood prior to the signing of a consent form. It is a legal document that gives the physician permission to perform the procedure.

Advanced Directive
An advanced directive is a legal document used to outline a patient's preferences for specific treatments, which may be experimental or carry significant risks. This directive ensures that a patient's wishes regarding therapies like gene editing or stem cell transplants are respected, especially if they become unable to make decisions for themselves.


