Tehran University of Medical Sciences Immunology and Genetics Journal 2645-4831 6 4 2023 12 22 137 140 Taher Cheraghi 17th Shahrivar Children’s Hospital, Department of Pediatrics, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran. Aye Mir Emarati 17th Shahrivar Children’s Hospital, Department of Pediatrics, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran. Afrooz Moradkhani Dezful University of Medical Sciences, Dezful, Iran 2024 09 28 2024 10 13 It has been established that mutations of the Recombinase activating genes (RAG1 and RAG2) are responsible for classic T-B-NK+ severe combined immunodeficiency (SCID). On the other hand, it has now become evident that certain mutations within these genes can also lead to other forms of combined immunodeficiency, antibody deficiency, and even autoimmunity. In this report, we present a case involving a 9-month-old female patient who presents with clinical and laboratory findings indicative of systemic lupus erythematosus (SLE). Following the diagnosis of early-onset SLE and considering the presence of concurrent infections, it was considered necessary to investigate potential underlying monogenic disorders associated with inborn errors of immunity. Immunological evaluations demonstrated a combined immunodeficiency and whole exome sequencing confirmed that the patient has a mutation in the RAG1 gene. https://igj.tums.ac.ir/index.php/igj/article/view/151 https://igj.tums.ac.ir/index.php/igj/article/download/151/133