A case of severe combined immunodeficiency caused by adenosine deaminase deficiency with a new mutation.

Abstract

Adenosine deaminase (ADA) deficiency is among the most common causes of severe combined immunodeficiency, characterized by dysfunction of the T, B, and natural killer (NK) cells (T-B-NK-SCID) and severe lymphopenia.1 ADA is a key enzyme in the purine salvage pathway, the absence of which causes lymph-toxic deoxyadenosine triphospate (dATP) accumulation, inhibiting ribonucleotide reductase, a critical enzyme for DNA replication and repair. This effect impairs the lymphocyte development and function resulting in severe combined immune deficiency (SCID).1,2 ADA deficiency is autosomal recessively inherited through mutations in the ADA gene, which is located on chromosome 20q13.12. Herein, we will describe the identification of a novel splicing mutation in the ADA gene in a patient with SCID