ABSTRACT
ABSTRACT Introduction: Colombia has been subject to intense genetic and cultural currents due to its geographical location. Hemoglobinopathies are the most common recessive diseases found worldwide and represent an important public health problem, according to the region and ancestry of each country. Objectives: To evaluate the frequency of hemoglobin variants according to the geographical region in a population group adjusted to sex and age in Colombia. Methods: This was a descriptive retrospective study of hemoglobin variants performed by electrophoresis in patients treated at and/or referred to specialized care institutions in Bogota, Colombia between January 2009 and December 2020. Results: A total of 2,224 results were analyzed, 48.4% male and 51.5% female; 63.3% of patients were without alterations, 14.3% presented with thalassemia, 17.3%, HbS, 2.3%, HbS/C, 1.8%, HbC, 0.5%, HbE and 0.5% persistent HbF, with HbS being more prevalent in males (p = 0.005). When assessing the geographical regions of Colombia, a higher prevalence of HbS was found in the Pacific (p = 0.005) and Caribbean regions, while Thalassemia and HbS were more prevalent in the Andean and Orinoquia regions, and it was rare to find any hemoglobinopathies (p = 0.0001) in the Amazonian region. Conclusions: The main hemoglobinopathies found in Colombia are HbS, predominantly in males, and Thalassemia. The distribution of hemoglobinopathies in different geographical regions of Colombia is influenced by ancestry.
ABSTRACT
A hemoglobina C (Hb C) é originária do oeste da África e é detectada por migração lenta na eletroforese alcalina em acetato de celulose. Consiste na mutação do gene da globina beta no códon 6 (GAG-AAG), resultando na substituição do sexto aminoácido da cadeia beta da hemoglobina humana, o ácido glutâmico, pelo aminoácido lisina. A cromatografia de alto desempenho (HPLC) separa completamente as frações C e A2, permitindo caracterizar a presença da interação com talassemia beta. Esta entidade (Hb CC, em homozigoze) é considerada benigna em relação à doença falciforme, já que a falcização não faz parte de sua fisiopatologia. A raridade do diagnóstico C homozigoto e C talassemia beta nos pacientes portadores de hemoglobinopatias nos alertou para a necessidade de se conhecer melhor e estudar aspectos clínicos e hematológicos dos casos dessa mutação em homozigose e na interação com a talassemia beta no ambulatório de anemias do Centro Regional de Hematologia e Hemoterapia de Ribeirão Preto, SP, Brasil.
Hemoglobin C (Hb C) originated in the west of Africa and is detected by alkaline electrophoresis by slow migration in cellulose acetate. It consists of a mutation of the beta globin gene in codon 6 (GAG-AAG), resulting in a substitution of glutamic acid, the sixth amino acid of the beta string of the human hemoglobin, for lysine. High performance chromatography (HPLC) separates the C and A2 fractions completely, allowing the characterization of the presence of interactions with thalassemia beta. This entity (Hb CC) is considered benign in respect to sickle cell disease, as sickle cells are not part of its physiopathology. The rarity of the diagnosis of homozygous C and beta thalassemia in patients with hemoglobinopathies showed the necessity of studying clinical and hematologic aspects of the cases of this mutation in homozygosis carriers and the interaction with beta thalassemia in the anemias clinic of the Regional Blood Center in Ribeirao Preto, SP, Brazil.