Pilot Phase I/II Study of Amino Acid Leucine in Treatment of Patients With Transfusion-Dependent Diamond Blackfan Anemia

This study will determine the safety and possibility of giving the amino acid, leucine, in patients with Diamond Blackfan anemia(DBA)who are on dependent on red blood cell transfusions. The leucine is expected to produce a response in patients with DBA to the point where red blood cell production is increased. Red cell transfusions can then be less frequent or possibly discontinued. The investigators will study the side effects, if any, of giving leucine to DBA patients. Leucine levels of leucine will be obtained at baseline and during the study. The drug leucine will be provided in capsule form and taken 3 times a day for a total of 9 months.