 During the study, patients will be admitted to the NIH Clinical Center on an outpatient basis to evaluate their response to the copper histidine treatment. These evaluations will take place every 8 months, with a final evaluation performed after 3 years of treatment. During the outpatient visits, patients will be required to give blood and urine samples for testing and undergo ultrasound testing. They will also undergo brain MRI scans at the initial visit and at the 16-month and 36-month visits. Patients who agree will give additional blood samples for genetic research purposes. 