The first gene therapy (somatic enzyme) was successfully done in:

A i.e. SCID - The goal of gene therapy is replacement of abnormal mutant gene by normal geneQ. - Technique to transfer genes (foreign material) into cells include - transfection, microinjection, electroporation, site directed recombination, transduction using adenovirus or retrovirus and plastnid liposome complexQ etc. SCID (Severe combined imuunodeficiency disease) or bubble baby syndrome is the first disease treated successfully by gene therapy.