The purpose of this research study is to test a new method of cell processing for stem cell transplants with an unrelated donor or partially matched related donor for patients with BMF who do not have a well matched related donor.

The purpose of this research study is to understand the impact of transplant on the quality of life of the entire family including sibling donors, other siblings and parents.

The study will enroll male and female patients between 2 years to 25 years of age with sickle cell disease or beta thalassemia major, who do not have a matched related donor, and their doctor feels their condition should be treated with hematopoietic stem cell transplantation (HSCT).