<prompt> In 1990, for the first time, Michaele Blease and W. French Andresco of National Institute of Health, Bethesda, U.S.A. attempted gene therapy on a human patient. Which of the following disease was attempted to be cured?Cystic fibrosisHaemophiliaThalassemiaSevere Combined Immunodeficiency Disease  <response>: The first convincing therapeutic effect from gene transfer occurred with : SCID Impoant types of defects in SCID: X-linked Severe Combined Immunodeficiency Disease SCID: mutations in the gene IL2RG. IL2RG encodes gc subunit of cytokine receptors. Inheritance pattern: X-Linked. Most common defect in SCID patientsQ. Most common cause of SCID is IL2R defect. Autosomal Recessive SCID: ADA Adenosine Deaminase enzyme deficiency. gene therapy is done for ADA deficiency SCID. 