Abstract
BACKGROUND: Oral mucositis (OM) is a painful inflammation resulting from chemotherapy. It is dependent on factors such as age, gender, chemotherapy regimen, oral health, immunological and nutritional status, and genetics. OBJECTIVES: The aim of the study was to conduct a narrative review to compile studies on the contribution of genetic and epigenetic aspects to the pathogenesis of OM in children with haematological malignancies undergoing chemotherapy treatment. METHODS: The literature search was performed in Pubmed, Scopus, Web of Science, Cochrane, Lilacs, and grey literature databases covering articles published since 2010. RESULTS: Twenty-two studies investigating polymorphisms and four studies investigating DNA methylation were included. Polymorphisms in the MTHFR, ABCB1, ABCC2, ABCG2, SLCO1B, miR-1206, miR-3683, CAT, and VDR genes were associated as risk factors for OM and polymorphisms in the TYMS and miR-4268 genes were associated as protective factors. With regard to DNA methylation, associations such as protection or susceptibility to OM have not yet been proven. However, studies have shown that DNMT1 methylation and hypomethylation in total DNA and in the TNF-α gene are associated with recovery of the oral mucosa. CONCLUSIONS: Genetic variants are associated with OM in various biological pathways, such as folate metabolism, transport proteins, epigenetic machinery, oxidative stress, and vitamin D metabolism. The DNA methylation profile, which is still poorly understood in the pathogenesis of OM, is associated with mucosal recovery (inflammation and epigenetic machinery). Genetic and epigenetic markers may be tools to indicate a patient's susceptibility to developing OM, and epigenetic markers may be a target for therapies.