ADA-SCID, also known as Severe Combined Immunodeficiency caused by Adenosine Deaminase deficiency, is a rare genetic disorder that affects the immune system. The disease causes a compromised immune system, leaving the affected individual susceptible to infections and autoimmune disorders. There are various synonyms for ADA-SCID, including Adenosine Deaminase Deficiency (ADD), Severe Combined Immune Deficiency (SCID), and Boy in the Bubble Syndrome. While these terms may be used interchangeably, it is essential to understand the underlying cause of the disease and the impact it has on the individual's immune system. Treatment includes gene therapy or bone marrow transplant, and early diagnosis is crucial in managing the condition effectively.