The first clinical gene therapy was given for the treatment of:

Adenosine deaminase deficiency

The correct answer is Option (3) → Adenosine deaminase deficiency

Gene therapy is a medical approach used to treat genetic disorders by manipulating genes. It involves introducing or altering genetic material in a person's cells to correct or replace the faulty or missing gene responsible for the disorder. The ultimate goal of gene therapy is to restore normal function to the affected cells and alleviate the symptoms of the genetic disorder.

Gene therapy is a collection of methods that allows correction of a gene defect that has been diagnosed in a child/embryo. Here genes are inserted into a person’s cells and tissues to treat a disease. Correction of a genetic defect involves delivery of a normal gene into the individual or embryo to take over the function of and compensate for the non-functional gene. The first clinical gene therapy was given in 1990 to a 4-year old girl with adenosine deaminase (ADA) deficiency.This enzyme is crucial for the immune system to function. The disorder is caused due to the deletion of the gene for adenosine deaminase.