Abstract
Fetal hemoglobin (HbF) is a potent genetic modifier of β-thalassemia phenotype. B-cell
lymphoma 11A (BCL11A) gene results in significant silencing of HbF. The aim of this study was to assess
the prevalence of different BCL11A genotypes among a cohort of Egyptian children with β-thalassemia and to correlate
them to HbF and clinical severity score. Eighty-two children with β-thalassemia (aged
12.95 ± 3.63 years) were recruited from the Pediatric Hematology Clinic, Ain Shams
University. They were divided based on the clinical severity of β-thalassemia into
three subgroups: 20 mild (24.4%), 24 moderate (29.3%), and 38 severe (46.3%). Age,
gender, age of diagnosis, initial HbF level, transfusion history, and history of splenectomy
were assessed. Anthropometric measures, signs of anemia and hemosiderosis, and the
severity score were determined. Laboratory investigations such as complete blood picture,
ferritin, and single gene polymorphism genotyping of the rs11886868 were also performed.
Our findings showed that 16 children had CC genotype (19.5%), 38 had TC genotype (46.3%),
and 28 had TT genotype (34.1%) of the rs#. β-thalassemia children with TT genotype
had significantly higher severity scoring than the other two groups (p < 0.001). Moreover, mean initial HbF was found to be lower in children with TT genotype
followed by TC and CC genotypes (p < 0.001). Increased γ-globin expression associated with BCL11A gene polymorphism is associated with better clinical severity of β-thalassemia.
Keywords
BCL11A polymorphism - β-thalassemia - phenotypic heterogeneity
