Participants will provide a blood sample (about 8 to 10 teaspoons from adults; 1 to 3 teaspoons from children) or sample of skin cells collected by swabbing the inner surface of the cheek. Some patients may undergo a skin biopsy, in which a small skin sample (about 1/8-inch in diameter) is surgically removed. The tissue samples will be used to obtain DNA (genetic material) for laboratory testing. A permanent cell line-a collection of cells grown in the laboratory from the original tissue specimen-will also be established to enable additional testing in the future.