Investigation of ADA Enzyme Deficiency

This observational study was designed as a prospective epidemiological screening study. Patients who applied to the centers participating in the study and were found to be lymphopenic in at least one examination will be included in the study. Up-to-date data will be collected from patients who have agreed to participate in the study, and a blood sample will be taken from patients on Guthrie paper. The blood taken will be sent to the Duzen Laboratories center located in Ankara and will be subjected to ADA metabolites analysis. For patients with a high metabolic test, the responsible investigator will advise on clarifying the diagnosis with a genetic test other than the study. In case of formation of new information for each patient, consultation will be provided by the responsible researcher. Thus, the prevalence of ADA enzyme deficiency disease in patients with lymphopenia will be evaluated. In addition, with this study, it will be scientifically demonstrated whether lymphopenia is a parameter that facilitates early diagnosis of ADA patients.