RecruitingCombination productGene Therapy for Adenosine Deaminase Severe Combined Immune Deficiency Using Peripheral Blood and EFS ADA VectorThe aim of this study is to assess the safety and efficacy of autologous transplantation of hematopoietic stem cells (CD34+ cells) from mobilized peripheral blood (mPB) of ADA-deficient SCID infants and children following human ADA gene transfer by the EFS-ADA lentiviral vector. The level of gene transfer in blood cells and immune function will be measured as endpoints.