Compound Heterozygosity of β-Thalassemia and the Sickle Cell Hemoglobin in Various Populations of Chhattisgarh State, India

Abstract

Hemoglobinopathies evolved as a protective mechanism against malaria, which exhibit selective advantage in the heterozygous state. However, in a homozygous recessive condition, it poses a serious socioeconomic burden. Sickle cell anemia is an autosomal recessive hemoglobinopathy associated with erythrocytes sickling, vaso-occlusive crisis (VOC), as well as multi-organ failure and death. The coinheritance of other hemoglobinopathies is known to substantially modulate the clinical manifestation of sickle cell anemia. In the present study, we aimed to analyze the coinheritance of β-thalassemia (β-thal) in Hb S (HBB: c.20A>T) patients. The study includes 918 sickle cell anemia patients from 10 ethnic populations of Chhattisgarh State, India. Complete blood counts (CBCs) and hemoglobin (Hb) high performance liquid chromatography (HPLC) fractionation data were collected from patient record books. We observed Hb S-β-thal in all the analyzed populations. Interestingly, high frequencies of Hb S-β-thal have been observed in Satnami (53.8%), Rawat (47.1%), Gond (35.1%) and Panika (30.6%) populations. Inter-population comparison of hematological parameters [Hb F (p < 0.001), Hb A₂ (p < 0.001), Hb (p = 0.03) and red blood cell distribution width (RDW) (p < 0.001)] revealed significant differences. We also observed that mean Hb F levels were significantly higher in Hb S compared to Hb S-β-thal patients in the respective populations. Our study highlights the higher prevalence of β-thal as well as the compound heterozygosity for Hb S and β-thal in various populations of Chhattisgarh State, India.

Keywords:

• β-Thalassemia (β-thal)
• Chhattisgarh State
• compound heterozygosity
• Fetal hemoglobin (Hb F)
• sickle cell anemia
• sickle cell disease

Acknowledgements

We wish to thank the Sickle Cell Institute Chhattisgarh, Raipur, India for providing their facilities. ANJ planned and designed the experiment; ANJ and IP collected the patient’s data; ANJ, BVKSL and HV analyzed the results; ANJ, BVKSL and HM prepared the manuscript; ANJ and BVKSL prepared the final manuscript. All the authors have read and approved the manuscript.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Funding

The authors received no specific grant from any funding agency in the public, commercial or not-for-profit sectors. However, ANJ acknowledges funding from the Chhattisgarh Council of Science and Technology [grant number 3168/CCOST/MRP/2017], Raipur, India.