![]() ![]() Patients with HbAS are not considered within the spectrum of SCD as most of them never present with typical symptoms of SCA. The coinheritance of beta-naught thalassemia and sickle cell mutation leads to HBS-Beta-0 disease, which phenotypically behaves like HBSS disease.Ī heterozygous inheritance leads to HbAS. A homozygous mutation leads to the severest form of SCD, i.e., SCA- also called HBSS disease. The mutation is transmitted via Mendelian genetics and is inherited in an autosomal codominant fashion. The sickle cell mutation occurs when negatively charged glutamine is replaced by a neutral valine at the sixth position of the beta-globin chain. HbF- comprises two chains of the alpha-globin and two chains of the gamma-globin (a2g2) - This Hb is more prevalent in the fetus (due to the high oxygen binding affinity that helps extract oxygen from maternal circulation). Since then, the treatment of sickle cell has taken to new heights by introducing several new agents (voxelotor, crinzalizumab, L-glutamine) and, most recently, gene therapy. first reported the use of hydroxyurea in increasing the levels of HbF. Recent advances in the field, more so within the last three decades, have alleviated symptoms for countless patients, especially in high-income countries. In 1984, Platt et al. Since the first description of the irregular sickle-shaped red blood cells (RBC) more than 100 years ago, our understanding of the disease has evolved tremendously. Sickle cell anemia is the most common form of SCD, with a lifelong affliction of hemolytic anemia requiring blood transfusions, pain crises, and organ damage. Lastly, it is essential to mention the sickle cell trait (HbAS), which carries a heterozygous mutation and seldom presents clinical signs or symptoms. Several other minor variants within the group of SCDs also, albeit not as common as the varieties mentioned above. Within the umbrella of SCD, many subgroups exist, namely sickle cell anemia (SCA), hemoglobin SC disease (HbSC), and hemoglobin sickle-beta-thalassemia (beta-thalassemia positive or beta-thalassemia negative). Linus Pauling described the molecular nature of sickle hemoglobin (HbS) in his paper 'Sickle Cell Anemia Hemoglobin.' Ingram Vernon, in 1956, used a fingerprinting technique to describe the replacement of negatively charged glutamine with neutral valine and validated the findings of Linus Pauling. Beet described the patterns of inheritance in patients with SCD. Ernest Irons reported noticing 'sickle-shaped' red cells in a dental student (Walter Clement Noel from Grenada). Africanus Horton in his book The Disease of Tropical Climates and their treatment (1872). Sickle cell disease (SCD) refers to a group of hemoglobinopathies that include mutations in the gene encoding the beta subunit of hemoglobin. The first description of SCA 'like' disorder was provided by Dr. ![]()
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