Anemia — A blood condition in which the level of hemoglobin
or the number of red blood cells falls below normal values.
Common symptoms include paleness, fatigue, and shortness of
Bilirubin — A yellow pigment that is the end result of
hemoglobin breakdown. This pigment is metabolized in the liver
and excreted from the body through the bile. Bloodstream
levels are normally low; however, extensive red cell destruction
leads to excessive bilirubin formation and jaundice.
Bone marrow — A spongy tissue located in the hollow centers
of certain bones, such as the skull and hip bones. Bone marrow
is the site of blood cell generation.
Bone marrow transplantation — A medical procedure used to
treat some diseases that arise from defective blood cell
formation in the bone marrow. Healthy bone marrow is
extracted from a donor to replace the marrow in an ailing
individual. Proteins on the surface of bone marrow cells must be
identical or very closely matched between a donor and the
Desferoxamine — The primary drug used in iron chelation
therapy. It aids in counteracting the life-threatening buildup of
iron in the body associated with long-term blood transfusions.
Globin — One of the component protein molecules found in
hemoglobin. Normal adult hemoglobin has a pair each of alphaglobin
and beta-globin molecules.
Heme — The iron-containing molecule in hemoglobin that
serves as the site for oxygen binding.
Hemoglobin — Protein-iron compound in the blood that carries
oxygen to the cells and carries carbon dioxide away from the
Hemoglobin A — Normal adult hemoglobin that contains a
heme molecule, two alpha-globin molecules, and two betaglobin
Hemoglobin electrophoresis — A laboratory test that separates
molecules based on their size, shape, or electrical charge.
Hepatomegaly — An abnormally large liver.
HLA type — Refers to the unique set of proteins called human
leukocyte antigens. These proteins are present on each
individual’s cell and allow the immune system to recognize ‘self’
from ‘foreign’. HLA type is particularly important in organ and
Hydroxyurea — A drug that has been shown to induce
production of fetal hemoglobin. Fetal hemoglobin has a pair of
gamma-globin molecules in place of the typical beta-globins of
adult hemoglobin. Higher-than-normal levels of fetal
hemoglobin can ameliorate some of the symptoms of
Iron overload — A side effect of frequent blood transfusions in
which the body accumulates abnormally high levels of iron. Iron
deposits can form in organs, particularly the heart, and cause
Jaundice — Yellowing of the skin or eyes due to excess of
bilirubin in the blood.
Mutation — A permanent change in the genetic material that
may alter a trait or characteristic of an individual, or manifest as
disease, and can be transmitted to offspring.
Placenta — The organ responsible for oxygen and nutrition
exchange between a pregnant mother and her developing baby.
Red blood cell — Hemoglobin-containing blood cells that
transport oxygen from the lungs to tissues. In the tissues, the
red blood cells exchange their oxygen for carbon dioxide, which
is brought back to the lungs to be exhaled.
Screening — Process through which carriers of a trait may be
identified within a population.
Splenomegaly — Enlargement of the spleen.