Serum ADA2 enzymatic activity of suspected DADA2 patients. (A) ADA2 enzyme activity (U/L) measured in serum samples of suspected DADA2 patients (n = 10), adult healthy controls (n = 35), pediatric healthy controls (n = 17), healthy DADA2 carriers (n = 19), and DADA2 patients (n = 18). Each data point is plotted with the mean ± SD. Statistical significance was assessed using the Mann–Whitney U test, ***P < 0.0001. (B) ADA2 protein secretion in serum samples of pediatric controls, adult controls, DADA2 patients, and cohort patients by western blot. (C) Quantification of ADA2 secretion in serum samples of pediatric controls, adult controls, DADA2 patients, and cohort patients. Bar graphs represent the percentage of ADA2 protein secretion relative to pediatric/adult controls. Each bar represents the mean ± SD from three independent experiments. (D) Longitudinal follow-up of ADA2 enzymatic activity in serum samples of P5, P7, and P8. Source data are available for this figure: SourceData F7.