Analysis of Common Beta-Thalassemia (β-Thalassemia) Mutations in East Java, Indonesia

Abstract

BackgroundThe frequency of the beta-thalassemia (β-thalassemia) gene in Indonesia ranges from 3 to 10%. However, in the East Java province, there is still limited information on the prevalence of β-thalassemia mutations in clinically diagnosed beta-thalassemia patients of East Java. Therefore, this study aimed to characterize β-thalassemia mutations in selected patients in the East Java province of Indonesia.MethodsThis is an analytical observational study. Diagnosis of β-thalassemia was based on clinical presentation, complete blood count (CBC), and hemoglobin (Hb) electrophoresis. Blood specimens taken from each patient in three ethylenediaminetetraacetic acid (EDTA) tubes were analyzed for CBC and Hb electrophoresis and processed for DNA extraction and subsequent polymerase chain reaction (PCR). Detection of mutations in Hemoglobin Subunit Beta (HBB) gene exons 1–3 of the β-thalassemia gene as the common mutation in Indonesia was done using PCR followed by Sanger sequencing.ResultsIn total, 33 (n = 33) participants were involved in this study with ages ranging from 5 to 17 years comprising 19 women and 14 men. Their ethnic origins were Javanese (n = 30) and Chinese (n = 3). CBC results showed that mean ± standard deviation (SD) for Hb, red blood cell (RBC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and red cell distribution width (RDW)-CV were 81.2 ± 7.0 g/L; 3.40 ± 0.39 × 109/L; 71.05 ± 5.72 fL; 24.12 ± 2.45 pg; 33.91 ± 1.47 g/dl; 24.38 ± 6.02%, respectively. Hb electrophoresis revealed that 5 out of 33 participants had beta-thalassemia and 28 out of 33 participants had hemoglobinopathy (Hb) E/beta-thalassemia. Results of Sanger sequencing showed the following genotype variations in the samples: 12 (36.4%) with βCD26/βIVS−I−5; 6 (18.2%) with βCD26/βCD35; 3 (9.1%) with βCD26/βIVS−I−2; 2 (6.1%) with βCD27/28/βCD40; 2 (6.1%) with βIVS−I−1/βCAP+1; and βCD26/βIVS−I−1; βIVS−I−5/βCAP+1; βIVS−I−5/βCD35; βCD26/βCD37; βCD26/βCD15; βCD26/βCD40; and βIVS−I−5/βCD19 in 1 (3%) sample, respectively, and 1 (3%) had no abnormality detected in sequencing even though electrophoresis showed abnormality in the migration pattern. The βCD26/βIVS−I−5 mutation was found in samples that were noted to have Hb E/beta-thalassemia on Hb electrophoresis.ConclusionThe underlying genetic variations are heterogeneous in thalassemia patients in East Java, where 12 variants were found. The most common variant was βCD26/βIVS−I−5, which all accounted for Hb E/beta-thalassemia on Hb electrophoresis. Furthermore, 28 out of 33 participants had hemoglobinopathy (Hb) E/beta-thalassemia.

Analysis of Hepcidin and Interleukin-6 Levels among Transfusion-Dependent Thalassemia Patients With and Without Alloimmunization/Autoimmunization

“…26 A study in Indonesia by Tambunan et al demonstrated a prevalence of women, with the highest mean age in the thalassemia group with positive allo-immunization being 13 years, 27,28 which aligns with findings at RSUD Dr. Soetomo, reporting a similar mean age of 11.7 years. 5 This aligns with the thalassemia prevalence study by Hernaningsih et al in East Java, covering the age range of 5-17 years, 29 and with the study by Fatmasyithah et al in Aceh, which focuses on the age range of 5-12 years. 30 Blood type O positive was predominant in both groups, consistent with findings in Indonesia and India.…”

Comparison of Lysis Buffers for Saliva DNA Extraction using Modified Magnetic-Silica Nanoparticle Beads

“…It indicated that DNA extracted from saliva using MAGSi combined with lysis buffer and without lysis buffer could amplify specific genes. The human β-globin gene was used because this single target gene is often used for genotyping of thalassemia mutation [29]. In addition, the amplicon was of medium length, so it did not need extended reaction time [28,42].…”

“…DNA amplification was carried out in a thermal cycler (T100, Bio-Rad). The reaction was done using protocols from Hernaningsih et al 2022 [29]. Amplification was started by a pre-denaturation reaction at 95°C for 2 mins.…”