Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 21 3 2022 06 18 364 368 Afshin Ghaderi Department of Internal Medicine, Hematology and Medical Oncology Ward, Yasuj University of Medical Sciences, Yasuj, Iran Tahereh Bakhtiari Department of Immunology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran Saeid Jokar Department of Internal Medicine, Shahids Rajaee Hospital of Gachsaran, Yasuj University of Medical Sciences, Yasuj, Iran Abbas Eshraghi Department of Internal Medicine, Qom University of Medical Sciences, Qom, Iran 2021 09 05 2021 10 26 Fetal hemoglobin is the principal hemoglobin in the human fetus, and the adult levels of fetal hemoglobin (HbF) are less than 1% of total hemoglobin. A steady increase of HbF in patients with hereditary persistence of fetal hemoglobin (HPFH) is associated with complications. The present report describes HPFH in a 26-year-old man with emphasis on its hemoglobin electrophoresis. The patient was admitted with complaints of recurrent weakness and lethargy, weight loss, abdominal pain, and dyspepsia. Splenectomy was planned due to massive splenomegaly and gastrointestinal complications. Ultimately,  electrophoresis confirmed the diagnosis of HPFH. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/3348 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/3348/1803