To study patients' DNA, the researchers will obtain a blood sample of about 4 teaspoons from patients 10 years or older. A smaller amount of about 1 teaspoon for each 5 lb. of body weight will be collected from younger patients. Those DNA samples will be used only for research in the genetic disorder in a patient's family. No other testing or research will be conducted on the blood samples without patients' separate permission. Also, the DNA will be stored by codes that the researchers define and contained in a secured building.