DNA damage in children with β-thalassemia minor: genotoxicity assessment by comet assay

In transfusion-dependent forms of β-thalassemia, chronic anemia and iron overload lead to the development of oxidative stress-related DNA damage. In β-thalassemia minor (β-Tm), oxidative stress resulting from an unbalanced globin chain ratio has been documented, even in the absence of anemia and its complications. However, the status of oxidative stress-related DNA damage has not yet been elucidated. The aim of this study was to assess DNA damage in β-Tm in a pediatric population.

We compared 142 children with β-Tm to 113 healthy controls, including siblings of the β-Tm individuals. The comet assay was used to assess DNA damage in peripheral blood lymphocytes. Additionally, oxidative stress markers and biochemical parameters were measured.

No significant differences were observed between the β-Tm group and controls in terms of demographics, biochemical parameters, or baseline oxidative stress levels (p>0.05). In the comet assay, there was no difference in tail intensity (TI) between subjects and controls, nor between siblings with and without β-Tm (p=0.551 and p=0.655, respectively). However, when the β-Tm group was divided by age, a gradual increase in DNA damage, as measured by TI, was observed. This increase was more pronounced in the β-Tm group compared to controls.

We observed no significant differences in DNA damage between β-Tm individuals and controls. However, TI increased at a faster rate with age in carriers compared to non-carriers, suggesting that environmental factors might exert a more pronounced influence on the genetic integrity of individuals with a β-Tm background. Although β-Tm itself does not seem to pose a substantial genotoxic risk in childhood, our findings underscore the importance of further research into the interplay between β-Tm and other risk factors throughout life. We advocate for long-term monitoring of β-Tm children to assess the health and potential genetic consequences.