Determination of Beta Thalassemia trait and abnormal Hemoglobin variant frequency
Determinación del rasgo de beta talasemia y la frecuencia de variantes anormales de hemoglobina
Miraç Seher Helvacı, Melih Tekinay, Okan Yılmaz, Mustafa Şahin, Belkız Öngen İpek, Eren Vurgun, Okan Dikker, Hüseyin Dağ
Abstract
Introduction: Hemoglobinopathies are among the most common hereditary disorders globally, classified into thalassemias and abnormal hemoglobins. Abnormal hemoglobins arise from genetic alterations like point mutations, insertions, or deletions, with Hb S, Hb D, Hb C, and Hb E being the most prevalent in Turkey. Beta-thalassemia minor is characterized by reduced or absent synthesis of one beta-globin chain. High-performance liquid chromatography (HPLC) is widely used for screening, while genetic methods remain the gold standard for definitive diagnosis. The estimated frequency of beta-thalassemia traits in Turkey is 2–3%, and abnormal hemoglobins 0.95%. This study aimed to determine the frequency of beta-thalassemia traits and abnormal hemoglobins in a central laboratory.
Material and methods: Retrospective data from hemoglobin variant analyses conducted between November 1, 2020, and July 31, 2024, in the hospital’s central laboratory were collected via the Laboratory Information Management System (LIMS). Samples from patients aged 6 months to 99 years were included. Repeated samples and those from infants under 6 months (with high HbF) were excluded. Frequencies of Hb S, D, C, and E were calculated as a percentage of total tested samples. HbA2 > 3.5% was used to identify beta-thalassemia traits. Analyses were performed using a cation-exchange HPLC-based Adams HA-8180T system.
Results: A total of 223,609 samples were analyzed. Abnormal hemoglobins were found in 0.35% (800 cases): Hb S (0.15%), Hb D (0.13%), Hb C (0.05%), and Hb E (0.01%). Beta-thalassemia traits (HbA2 ≥ 3.6%) were found in 6,017 cases (2.69%).
Conclusions: Hb S was the most frequent abnormal variant. The frequency of abnormal hemoglobins was lower than literature reports, while beta-thalassemia traits matched reported rates. HPLC is valuable for screening, but genetic testing remains essential for definitive diagnosis. These findings contribute to better prediction of hemoglobinopathy prevalence.
Keywords
Resumen
Introducción: Las hemoglobinopatías se encuentran entre los trastornos hereditarios más comunes a nivel mundial y se clasifican en talasemias y hemoglobinas anormales. Las hemoglobinas anormales se originan por alteraciones genéticas como mutaciones puntuales, inserciones o deleciones, siendo las Hb S, Hb D, Hb C y Hb E las más prevalentes en Turquía. La beta-talasemia menor se caracteriza por la síntesis reducida o ausente de una cadena de beta-globina. La cromatografía líquida de alta resolución (HPLC) se utiliza ampliamente para el cribado, mientras que los métodos genéticos siguen siendo el método de referencia para el diagnóstico definitivo. La frecuencia estimada de rasgos de beta-talasemia en Turquía es del 2-3%, y la de hemoglobinas anormales, del 0,95%. Este estudio tuvo como objetivo determinar la frecuencia de rasgos de beta-talasemia y hemoglobinas anormales en un laboratorio central.
Material y métodos: Se recopilaron datos retrospectivos de los análisis de variantes de hemoglobina realizados entre el 1 de noviembre de 2020 y el 31 de julio de 2024 en el laboratorio central del hospital mediante el Sistema de Gestión de Información de Laboratorio (LIMS). Se incluyeron muestras de pacientes de entre 6 meses y 99 años. Se excluyeron las muestras repetidas y las de lactantes menores de 6 meses (con HbF elevada). Se calcularon las frecuencias de Hb S, D, C y E como porcentaje del total de muestras analizadas. Se utilizó una HbA2 > 3,5% para identificar rasgos de beta-talasemia. Los análisis se realizaron con un sistema Adams HA-8180T basado en HPLC de intercambio catiónico.
Resultados: Se analizaron un total de 223.609 muestras. Se encontraron hemoglobinas anormales en el 0,35 % (800 casos): Hb S (0,15 %), Hb D (0,13 %), Hb C (0,05 %) y Hb E (0,01 %). Se encontraron rasgos de beta-talasemia (HbA2 ≥ 3,6 %) en 6017 casos (2,69 %).
Conclusiones: La Hb S fue la variante anormal más frecuente. La frecuencia de hemoglobinas anormales fue inferior a la descrita en la literatura, mientras que los rasgos de beta-talasemia coincidieron con las tasas reportadas. La HPLC es valiosa para el cribado, pero las pruebas genéticas siguen siendo esenciales para el diagnóstico definitivo. Estos hallazgos contribuyen a una mejor predicción de la prevalencia de hemoglobinopatías.
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References
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Submitted date:
01/20/2025
Reviewed date:
04/22/2025
Accepted date:
05/13/2025
Publication date:
05/15/2025
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