Which among the following is a cause of adenosine deaminase deficiency ?

Due to the inversion of the gene for adenosine deaminase. Due to the deletion of the gene for adenosine deaminase . Due to the gain of the gene for adenosine deaminase None of these.

Due to the deletion of the gene for adenosine deaminase .

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.