What kind of therapy was given in 1990 to a four-year-old with Adenosine Deaminase (ADA) deficiency?
Gene therapy
Chemotherapy
Immunotherapy
Radiation therapy
As we have already discussed in Gene Therapy - ADA Deficiency Treatment -
Gene therapy is the technique of genetic engineering to replace ‘a faulty gene’ by a normal healthy functional gene. The first clinical gene therapy was given in 1990 to a 4-year old girl with adenosine deaminase (ADA) deficiency. Hence, the correct option is (a).