Adenosine deaminase

Adenosine deaminase (also known as ADA) is an enzyme involved in purine metabolism. It is needed for the breakdown of adenosine from food and from the turnover of nucleic acids in tissues. Adenosine cannot be deribosylated (removed from ribose) without first converting it to the related nucleoside inosine, which is then broken down further. Adenosine deaminase converts adenosine to inosine by the removal of an amine group. Mutations in the gene for adenosine deaminase causing it to not be expressed are one cause of severe combined immunodeficiency (SCID). Mutations causing it to be overexpressed are one cause of hemolytic anemia. There is some evidence that a different allelle (ADA2) may lead to autism.