Copyright@ Mohamed Samir M Khalil | Biomed J Sci & Tech Res | BJSTR. MS.ID.006079. 29922 Case Report ISSN: 2574 -1241 A Presentation of a Case of Hb E Homozygosity Awad M Al Qahtani 1 , Essam M Ahmed 2 and Mohamed Samir M Khalil 3 * 1 Department of Family and Community Medicine, College of Medicine, Najran University, Najran, Saudi Arabia 2 Pharmaceutical Division, National Research Centre, Egypt, Faculty of Applied Medical Sciences, Najran University, Najran, Saudi Arabia 3 Department of Clinical Pathology, Faculty of Medicine, Assiut University, Assiut, Egypt *Corresponding author: Mohamed Samir M Khalil, Department of Clinical Pathology, Faculty of Medicine, Assiut University, Assiut, Egypt DOI: 10.26717/BJSTR.2021.37.006079 ARTICLE INFO ABSTRACT Citation: Awad M Al Qahtani, Essam M Ahmed, Mohamed Samir M Khalil. A Presentation of a Case of Hb E Homozygosity. Biomed J Sci & Tech Res 37(5)-2021. BJSTR. MS.ID.006079. Received: August 02, 2021 Published: August 09, 2021 Background Almost a total of 1317 Hb variants have been identified (HbVar database) [1], the four most common worldwide are Hb S, Hb E, Hb C, and Hb D, in the order of decreasing prevalence [2]. Haemoglobin (Hb) E is the most prevalent variant in Southeast Asia (Thailand, Myanmar, Cambodia, Laos, Vietnam), where its prevalence is 30- 60% [3-6]. The prevalence of HbE in India is about 3.5% with an increased clustering in Kolkata (22%) and Assam (50-80%) [7]. Hb E results from a G→A substitution in codon 26 of the β globin gene. This produces an abnormal Hb (glutamate is replaced by lysine) and activates a cryptic splice site at codon 25-27 of the β-globin gene, resulting consequently in abnormal processing for messenger RNA (mRNA). The level of normally spliced mRNA become reduced and because a new stop codon is generated, the abnormally spliced mRNA become nonfunctional [7,8]. Fortunately, only a minor activation of the alternative splicing pathway is associated with this mutation resulting in a moderate reduction of the normally spliced βE globin mRNA 72. Hb E trait (E heterozygosity; ββE) and Hb E disease (E homozygosity; βEβE) are mild disorders. Although the Hb E mutation alone does not cause any significant clinical problems, its interactions with various forms of α and β thalassemia produce a very wide range of clinical syndromes of varying severity [8,9]. Different phenotypes could be noticed with the compound heterozygote state of Hb Eβ-thalassemia ranging from a complete lack of symptoms to transfusion dependency [3,7,8,10]. Experiments were carried out in vitro at temperatures ranging from 38 to 41°C showed that there was a mild instability of Hb E but there is no evidence that this is the case in vivo [9-14]. It is noticeable that the E allele causes a mild thalassemia, while Eβ0 thalassemia shows severe phenotypes. This marked paradox in phenotypes could not be fully explained up till now. It is reported that HbE is sensitive to oxidative stress. Does this or other properties of HbE explain the variable severity of the Eβ0 thalassemia? This question is still waiting for an answer [11]. The aim of this report is to present a case of Hb E homozygosity discovered accidentally trying to cast shadow on a mutation not prevalent in the Middle East. Case Report A Consent has been taken from a 26-year-old male, from Kolkata, India, came to Najran University Hospital, Saudi Arabia for routine investigation. He did not complain from anemia or receive treatment. He gave a history of hemolytic attack because of high fever indifintily due to infection with malaria and only one blood transfusion. On examination, there were no significant clinical findings such as organomegaly, icterus, or thalassemic bone changes. CBC were carried out using Sysmex XS 500i (Sysmex, https://www. sysmex.com/). It showed mild microcytic hypochromic anaemia