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?
**Core Concept**
The question pertains to the historical milestone of gene therapy in humans, which involves the direct manipulation of a patient's genes to treat or cure a disease. This concept is rooted in the field of molecular medicine and genetic engineering.
**Why the Correct Answer is Right**
In 1990, Michaele Blease and W. French Anderson conducted the first human gene therapy trial at the National Institutes of Health (NIH) in Bethesda, USA. The disease they attempted to treat was **Adenosine Deaminase (ADA) Deficiency**, a severe combined immunodeficiency (SCID) disorder. This condition results from a genetic mutation that impairs the production of the ADA enzyme, essential for the breakdown of toxic deoxyadenosine derivatives in lymphocytes. Without ADA, lymphocytes accumulate and die, leading to immunodeficiency and increased susceptibility to infections. The researchers used retroviral vectors to introduce a functioning ADA gene into the patient's bone marrow cells, aiming to restore ADA enzyme activity and improve immune function.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not relevant to the context of the question, which specifically mentions the first human gene therapy trial in 1990.
* **Option B:** While gene therapy has been explored for various diseases, this option does not accurately represent the disease targeted in the 1990 trial.
* **Option D:** This option is also not accurate, as the 1990 trial was focused on a specific genetic disorder rather than a broader category of diseases.
**Clinical Pearl / High-Yield Fact**
Gene therapy has evolved significantly since the first human trial in 1990, with ongoing research and advancements in vector design, gene editing, and delivery methods. Today, gene therapy is being explored for a wide range of diseases, including inherited disorders, cancer, and infectious diseases.
**Correct Answer:** C. Adenosine Deaminase (ADA) Deficiency.