If the ability of the immune system to distinguish between self and non-self cells is lost due to a genetic abnormality and it starts attacking self-cells, it leads to which of the following?

Autoimmune disease

When the immune system is functioning properly, it can distinguish between self-cells (cells belonging to the body) and non-self cells (cells that are foreign or potentially harmful). This ability is crucial for maintaining normal immune responses and protecting the body against pathogens.

However, in cases where there is a genetic abnormality or malfunction in the immune system, it may fail to recognize self-cells as "self" and mistakenly attack them. This condition is known as an autoimmune disease. In autoimmune diseases, the immune system produces antibodies or immune cells that target and attack the body's own tissues and organs.

Autoimmune diseases can affect various parts of the body, leading to chronic inflammation, tissue damage, and dysfunction of the affected organs. Examples of autoimmune diseases include rheumatoid arthritis, lupus, multiple sclerosis, and type 1 diabetes.

In the context of the given question, if the immune system attacks self-cells due to a genetic abnormality, it would result in an autoimmune disease. Therefore, the correct answer is (b) autoimmune disease.