Randomized study of DNA damage in children with cleft lip and palate living in regions with environmental toxicants

Relevance. DNA damage caused by exogenous factors acting on the maternal organism during preconception and early pregnancy plays a central role in the pathogenesis of congenital malformations. Many industrial toxicants released into the atmosphere possess teratogenic and mutagenic properties, among which benzo[a]pyrene and formaldehyde are of particular concern.

Objective. To conduct a randomized study to assess DNA damage by quantifying DNA strand breaks using the alkaline comet assay (single-cell gel electrophoresis) in isolated leukocytes from children with cleft lip and palate (CLP). The study compared three groups – children with CLP from regions with environmental toxicants, children with CLP from unexposed regions, and healthy controls from regions with elevated petrochemical emissions – to assess the association between DNA damage and CLP.

Materials and methods. The randomized study included 140 children aged 5–12 years divided into three groups: 60 children with CLP from regions with elevated atmospheric petrochemical emissions, 40 children with CLP from regions without petrochemical industry emissions, and 40 apparently healthy children from regions with elevated levels of atmospheric petrochemical pollutants. Peripheral venous blood was drawn after an overnight fast into EDTA tubes and transported to the Ufa Research Institute of Occupational Medicine and Human Ecology for comet assay analysis. DNA damage was assessed using the alkaline comet assay.

Results. Children with CLP living in regions with petrochemical pollutants showed markedly higher levels and prevalence of DNA damage. Comet tail length and % tail DNA differed significantly from those in healthy controls and in CLP children from unexposed regions, indicating heightened genotoxic stress associated with environmental exposure.

Conclusion. The differences in DNA damage levels among children from varying ecological conditions suggest that an unfavorable environmental background serves as a significant trigger of genotoxic stress potentially involved in the pathogenesis of cleft lip and palate.

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