Inclusion Criteria:

- Diagnosis of any disease for which a second or greater hematopoietic stem cell
transplant is needed due to insufficient donor chimerism following hematopoietic
recovery after previous HSCT. Determination of "insufficiency of donor chimerism"
will be made by the treating transplant physician. Occasionally donor derived
engraftment may be present, but sustained aplasia or failed recovery of sufficient
hematopoiesis requires administration of a second graft. This intervention may be
used for both situations.

- Donor Availability: Patients considered for transplantation must have a sufficient
graft as based on current criteria of the University of Minnesota Blood and Marrow
Transplantation Program

- Transplantation using sufficiently matched related donors (such as matched
siblings) or unrelated donors will be considered. Both granulocyte-colony
stimulating factor (GCSF) stimulated peripheral blood grafts and bone marrow
grafts will be considered, although bone marrow will be the priority.

- Cord blood grafts, both related and unrelated, are also eligible. As this
protocol will use a reduced intensity regimen, this protocol will use the
current recommendations of the University of Minnesota for choosing cord blood
grafts. If a single cord blood unit cell dose is insufficient, double cord
transplantation should be considered if sufficiently matched cord blood units
are available. The priority of choosing cord blood donors is based on the
current institutional recommendations.

- Exclusion of Metabolic Disorder or other Inherited Disorder Carrier Status from
related donor and unrelated cord blood grafts as appropriate for primary
disease.

At the discretion of the treating transplant physician, an allograft from the previous
donor may be used, if available.

- Age, Performance Status, Consent

- Age: 0 to 55 years

- Consent: voluntary written consent (adult or parental/guardian)

Exclusion Criteria:

- Previous irradiation that precludes the safe administration of an additional dose of
200 cGy of total body irradiation (TBI). Radiation Oncology will evaluate all
patients who have had previous radiation therapy or TBI for approval to receive an
additional 200 cGy of TBI

- Pregnant or breastfeeding

- Active, uncontrolled infection - infection that is stable or improving after 1 week
of appropriate therapy (4 weeks for presumed or documented fungal infections) will be
permitted

- HIV positive

- While it would be advantageous to begin therapy on this second transplant regimen > 6
months following a prior myeloablative regimen or >2 months after a reduced intensity
regimen, it is recognized that there are circumstances where this may not be
practical.