Preimplantation Genetic Diagnosis (PGD) is a powerful technique allowing the identification of disease-free embryos that are human leukocyte antigen (HLA) matched with the sibling in the family with a life-threatening disease. The purpose of PGD in bone marrow transplantation is to guarantee the birth of a child with HLA matched stem cells that can be used to treat the affected sibling.

The diseases for which PGD potentially can be used to prevent:

• Fanconi anemia
• Thalassemia
• Sickle cell disease
• Blackfan Diamond anemia
• Wiskott Aldrich Syndrome
• X SCID
• XLP
• Hurler syndrome
• MPS VI
• Adrenoleukodystrophy
• Mannosidosis
• Neurofibromatosis

Also, PGD can be used to find an embryo that will be HLA matched with the child that needs transplant. In addition to the diseases listed above, PGD can be used in families with a child with leukemia and aplastic anemia.

However, it is crucial to consult with a transplant physician before embarking on this option to:

• determine the appropriateness of this option for your family's situation,
• discuss in detail the potential risks and benefits, and
• monitor the affected child's disease for signs of progression that might limit the time available for pursuit of PGD and 'creation of a donor.'