Abstract Background Artemis deficiency is an autosomal recessive disorder characterized by a combined immunodeficiency with increased cellular radiosensitivity. In this review, the clinical and genetic characteristics of 15 patients with DCLRE1C variants are presented. Methods The demographic, clinical, immunologic, and genetic characteristics of patients with confirmed DCLRE1C variants diagnosed between 2013 and 2023 were collected retrospectively. Three patients were evaluated for radiosensitivity by the Comet assay, compared with age‐ and sex‐matched healthy control. Results Seven patients who had severe infections in the first 6 months of life were diagnosed with T‐B‐NK+ SCID (severe combined immunodeficiency). Among them, four individuals underwent transplantation, and one of those died due to post‐transplant complications in early life. Eight patients had hypomorphic variants. Half of them were awaiting a suitable donor, while the other half had already undergone transplantation. The majority of patients were born into a consanguineous family (93.3%). Most patients had recurrent sinopulmonary infections (73.3%), and one patient had no other infection than an acute respiratory infection before diagnosis. Two patients (13.3%) had autoimmunity in the form of autoimmune hemolytic anemia. Growth retardation was observed in only one patient (6.6%), and no malignancy was detected in the surviving 11 patients during the median (IQR) of 21.5 (12–45) months of follow‐up. Three patients who had novel variants exhibited increased radiosensitivity and compromised DNA repair, providing a potential vulnerability to malignant transformation. Conclusion Early diagnosis, radiation avoidance, and careful preparation for transplantation contribute to minimizing complications, enhancing life expectancy, and improving the patient's quality of life.

Artemis deficiency: A large cohort including a novel variant with increased radiosensitivity