Breadth of Donor Options for People With Inherited Diseases Requiring Allogeneic Hematopoietic Stem Cell Transplant in the Era of Alternative Donor Transplants Using Post-Transplantation Cyclophosphamide

Background: People who have certain immune system diseases often need a procedure called allo HSCT. This is short for allogeneic hematopoietic stem cell transplant. This might cure people with these diseases. Many people who need allo HSCT need donors who are relatives with similar genes. But the disease may also affect those in the donor pool. This may mean there are fewer options for people with inherited diseases. Researchers want to collect data on how transplant candidates and their donors are found. Objective: To find out how genetic diseases and the ways they are inherited affect the breadth of options for allo HSCT donors. Eligibility: Records from studies that have already been done. These will be for people ages 4 and older who were evaluated for allo HSCT or to be donors. Design: Participants already signed a consent form for their records to be shared. Researchers will study the participant data. Data will be stored in an electronic system. Researchers will use passwords to protect the data.