Amino acids — Twenty chemical "building blocks" that link together to form proteins. All amino acids have the same backbone, but each has a unique "side chain" coming off the backbone that gives it distinct properties. (Picture charms on a charm bracelet.)
Cancer — A disease in which cells in the body multiply out of control. These cells can spread to other organs in the body.
Carrier — A person who has one mutated copy of a recessive gene and one unchanged or normal copy of the same gene. Typically, carriers do not show any symptoms from carrying the mutated gene, but they can pass it on to their children.
Cell — The basic unit of a living organism. The cell contains the organism's genome, as well as the materials to build proteins. Cells can have specialized roles within the body. For example, nerve cells tell muscle cells to contract or relax.
Chromosome — Coils of DNA that are found in most of the body's cells. Humans have 46 chromosomes: 23 are inherited from the father and 23 from the mother.
Genetic tests — Laboratory tests that examine DNA, chromosomes, or proteins to look for genetic mutations that cause diseases.
Mutation — A change in the DNA sequence. Mutations can be inherited or they can occur spontaneously. If DNA in an egg or sperm contains a mutation, the mutation may be passed on to the next generation.
Protein — Molecules that are responsible for thousands of processes, structures, and materials in your body. Proteins consist of one or more chains of amino acids.