en Hematology Hematology case report case report <span style="font-size:14px;"><span style="font-family:Times New Roman;"><span style="line-height:14pt"><b><i><span style="color:blue">Background:</span></i></b> Hemoglobin J is one of the fast hemoglobin that has a more negative charge due to &beta;77His&rarr;Asp substitution. Acquisition of this hemoglobin is not associated with any specific clinical sign, but the combination of this hemoglobinopathy with beta-thalassemia and other hemoglobinopathies can cause challenges.</span><br> <span style="line-height:14pt"><b><i><span style="color:blue">Case Presentation:</span></i></b> In this article, two cases with hemoglobin J are introduced; the first patient for premarital testing and the other for his fatigue. The hemoglobin electrophoresis was done by Sebia capillary zone electrophoresis and Hb J as heterozygote and homozygote were determined.</span><br> <span style="line-height:14pt"><b><i><span style="color:blue">Conclusion:</span></i></b><b> </b>It must be noted that although this hemoglobinopathy is not related to any problem alone but could be confusing in combination with other hemoglobinopathies or thalassemia. In this paper, these two cases are introduced and an attempt was made to investigate the importance of molecular follow-up.</span></span></span><br> &nbsp; Hemoglobinopathy, Thalassemia, Hemoglobin J, Fast hemoglobin, Molecular diagnosis 586 589 http://caspjim.com/browse.php?a_code=A-10-2635-1&slc_lang=en&sid=1 Amin Solouki Aminsolouki.h@gmail.com 100319475328460043203 100319475328460043203 No Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran Tahereh Manoochehrabadi manoochehrabadit68@gmail.com 100319475328460043204 100319475328460043204 Yes Department of Tissue Engineering & Regenerative Medicine, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences (IUMS), Tehran, Iran Farzaneh Korani farzanekorani@gmail.com 100319475328460043205 100319475328460043205 No Hematology and Electrophoresis Department, Kermanshah Reference Laboratory, Kermanshah, Iran Mohammadreza Farshchi rezafarshchi100@gmail.com 100319475328460043206 100319475328460043206 No Hematology and Electrophoresis Department, Kermanshah Reference Laboratory, Kermanshah, Iran