Importance of the determination of enzymatic activity in the diagnosis of deficiency of adenosine deaminase 2 (DADA2)

Objective: To describe the usefulness of determining the enzymatic activity of adenosine deaminase 2 (ADA2) in patients with suspected ADA2 deficiency (DADA2).Method: Retrospective multicenter study. Review with analysis of the clinical, biochemical and genetic data of the patients in whom the enzymatic activity of ADA2 has been determined by spectrophotometric method.Result: In 3 of the 20 patients, the diagnosis of DADA2 was confirmed by the combination of redu-ced enzyme activity and biallelic pathogenic variants in the CECR1 gene. In 2 patients with variants of uncertain significance in CECR1, the study of enzymatic activity allowed to rule out the disease.Conclusions: The reduced enzymatic detection of ADA2 confirms the diagnosis of DADA2, particularly important in carriers of variants of uncertain significance in CECR1.(c) 2022 Elsevier Espana, S.L.U. All rights reserved.