Gene Transfer for X-Linked Severe Combined Immunodeficiency in Newly Diagnosed Infants

Inclusion Criteria:

• Treatment Eligibility Criteria:
  • Age <2 years at the time of enrollment.
  • No prior therapy with allogeneic stem cell transplantation.
  • A clinical diagnosis of SCID-X1 documented in the medical record.
  • A proven mutation in the common gamma chain gene as defined by direct sequencing of patient DNA.
  • Age > 2 months to < 1 year of age at the time of busulfan administration.
  • Less than 300 CD3+ T-cells by flow cytometry or higher if evidence of maternal engraftment as supported by peripheral blood FISH analysis for XY and XX.
  • Lymphocyte proliferation to phytohemagglutinin (PHA) <10% of the lower limit of normal for the laboratory.

Treatment Exclusion Criteria:

• Availability of a HLA matched sibling for allogeneic transplantation
• Prior therapy with allogeneic stem cell transplantation
• Positive for HIV infection by genome PCR
• Presence of a medical condition indicating that survival will be less than 16 weeks such as the requirement for mechanical ventilation, severe failure of a major organ system, or evidence of a serious, progressive infection that is refractory to medical therapy.
• The presence of any medical contraindications to general anesthesia and bone marrow harvest by aspiration
• A social situation indicating that the family may not be able to comply with protocol procedures and recommended medical care.