Association of XmnI Polymorphism with Foetal Haemoglobin Level and Severity of Thalassaemia in Children: A Cross-sectional Study
SC08-SC12
Correspondence
Dr. Aditi Baruah,
Professor and Head, Department of Paediatrics, Lakhimpur Medical College, North Lakhimpur, Assam-787051, India.
E-mail: aditibaruah2812@gmail.com
Introduction: The North-eastern Region of India has been a rich reservoir of haemoglobinopathies and thalassaemias. Genetic modifiers, commonly known as ameliorating factors, like co-inheritance of ?-thalassaemia, excess ? genes, the presence of the XmnI G? polymorphism and BCL11 Single Nucleotide Polymorphisms (SNPs), influence the reduction of the severity of Beta-thalassaemia. Early genetic diagnosis can aid in predicting a better prognosis and lower morbidity in thalassaemic children.
Aim: To find out the XmnI polymorphism among thalassaemic children admitted to the Paediatric Department for regular blood transfusions and to assess the relationship between XmnI polymorphism, disease severity and foetal haemoglobin levels.
Materials and Methods: This hospital-based cross-sectional study was done from June 2020 to May 2021 in the Department of Paediatrics and Anatomy at Assam Medical College and Hospital, Dibrugarh, Assam, India. A total of 96 thalassaemic children presenting to the thalassaemia daycare centre of the Paediatrics Department for repeated blood transfusions were included. Data collected from history and examination findings were recorded and the presence of XmnI polymorphism in their blood was tested using the Polymerase Chain Reaction-Restriction Fragment-length Polymorphism (PCR-RFLP) method. The association of XmnI polymorphism with disease severity and foetal haemoglobin levels was analysed using the Chi-square test, with a p-value of <0.05 considered significant.
Results: The mean age of the children was 10.1±4.4 years (range: 2 to 18 years), with a male-to-female ratio of 0.95:1. Among the participants, 59 (61.46%) had Haemoglobin (Hb) E-? thalassaemia and 37 (38.54%) had ? thalassaemia homozygous type. A total of 47 (48.96%) children exhibited the presence of XmnI polymorphism, of which 16 (34%) had ?-thalassaemia homozygous and 31 (66%) had Hb E-? thalassaemia. A significant association was found between this polymorphism and disease severity (p<0.001), but no significant association was observed with HbF levels (p=0.089). XmnI polymorphism was associated with hepatomegaly and stunting.
Conclusion: The present study demonstrated that the presence of XmnI polymorphism in thalassaemic children was associated with decreased disease severity, as these children presented at a later age and required fewer blood transfusions than those without this polymorphism. No association was found between XmnI polymorphism and HbF levels in the present study.