The following terms are briefly defined, primarily in terms of gene therapy.

antigen

a protein capable of inducing a specific immune response.

chromosome

strand or circle of DNA.

DNA

"deoxyribonucleic acid"; carries genetic information which is the basis of molecular heredity. Consists of a double helix joined by hydrogen bonds; the sequence of nucleotides determines individual hereditary characteristics.

ex vivo

delivery of the desired genes to target cells while they are outside the body (syn: in vivo).

gene

a specific sequence of nucleotides in DNA; functional units of heredity passed down by our parents.

gene therapy

replacing, removing, introducing, or otherwise altering genes in order to prevent or treat disease. Gene therapy affects the somatic cells of the body which includes all cell except the reproductive ones: sperm and egg cells.

genetic disorders

medical conditions caused by mutations in a gene or set of genes. Chromosomal abnormalities, single gene disorders, multifactorial disorders, and mitochondrial disorders are all genetic disorders.

germ line therapy (or germ line gene therapy)

gene therapy which affects the offspring of recipients. Goals of this type of therapy may involved irradicating certain genetic disorders. Because of it's "open-ended" nature (i.e. that it affects all the offspring resulting from the recipient and it's decendants), it is currently under much more scrutiny and controversy than gene therapy.

in vivo

delivery of the desired genes to target cells while they are inside the body (syn: ex vivo).

multifactorial disorder

a genetically linked disorder that is not purely the result of heredity; they are the result of multiple gene mutations and environmental factors. Examples: cancer, diabetes, heart disease.

prodrug (or benign compound)

a medically inactive percursor to a drug; it is converted into its active form by the body during the normal chemical process that take place inside cells.

Recombinant DNA

Genetic material which has been altered and recombined in the laboratory, generally from two different sources.

RNA

"ribonucleic acid."

suicide gene

name given to a group of genes used to make tumor cells more sensitive to drugs that otherwise wouldn't kill them.

vector

a carrier molocule used to transport the theraputic gene to the target cells. Usually, an virus modified to carry human DNA. Viruses pathogenic nature makes.