Deficiency of ADA and Severe Combined Immunodeficiency Disorder

Severe combined immunodeficiency disorder (SCID) is a rare genetic disorder that affects the immune system of the body. It occurs due to the deficiency of an enzyme called adenosine deaminase (ADA), which is required for the normal functioning of the immune system.

ADA and its Function

ADA is an enzyme that is responsible for breaking down a substance called adenosine, a nucleoside that is present in all cells of the body. Adenosine is broken down into inosine, which is then excreted from the body. ADA is particularly important for the normal functioning of the immune system, as it is required for the development and maturation of T and B cells, which are the key components of the immune system.

Deficiency of ADA and SCID

In SCID, the deficiency of ADA leads to the accumulation of toxic levels of adenosine and its metabolites, which damage the T and B cells, leading to a severe immunodeficiency. This means that individuals with SCID are unable to mount an effective immune response to infections, making them highly susceptible to infections by bacteria, viruses, and fungi.

Symptoms of SCID

The symptoms of SCID usually become apparent within the first few months of life and include recurrent infections, failure to thrive, chronic diarrhea, and skin rashes. Without treatment, most children with SCID do not survive beyond the first few years of life, as they succumb to severe infections.

Conclusion

In conclusion, deficiency of the enzyme ADA causes SCID, which is a rare genetic disorder that affects the immune system of the body. The deficiency of ADA leads to the accumulation of toxic levels of adenosine, which damage the T and B cells, leading to a severe immunodeficiency. Individuals with SCID are unable to mount an effective immune response to infections, making them highly susceptible to infections by bacteria, viruses, and fungi.