Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 22 4 2023 09 03 405 408 EN Elif Arik Department of Pediatric Allergy and Immunology, Gaziantep University Faculty of Medicine, Gaziantep, Turkey Ozlem Keskin Department of Pediatric Allergy and Immunology, Gaziantep University Faculty of Medicine, Gaziantep, Turkey Ercan Kucukosmanoglu Department of Pediatric Allergy and Immunology, Gaziantep University Faculty of Medicine, Gaziantep, Turkey Mahmut Cesur Department of Pediatric Allergy and Immunology, Gaziantep University Faculty of Medicine, Gaziantep, Turkey 2022 08 28 2023 05 17 Mutations in the SLC29A3 gene cause histiocytosis-lymphadenopathy plus (H) syndrome, a rare autosomal recessive genetic condition that affects numerous systems. We present a 7-year-old Syrian patient with pericardial effusion whose acute phase reactants did not decrease despite treatment. In order to emphasize the variety and raise awareness of H syndrome in the hopes of achieving an early diagnosis and appropriate treatment, molecular investigation of SLC29A3-related disorders is crucial. H syndrome is an uncommon genetic condition with a broad spectrum of phenotypes. Therefore, early genetic testing is essential for the accurate diagnosis of patients. Doctors should be aware of this condition and its symptoms and consider autoimmune diseases as a possible alternative diagnosis in patients with suspected immunodeficiency. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/3643 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/3643/1981