Genetic Variant Screening of DNA Repair Genes in Myelodysplastic Syndrome Identifies a Novel Mutation in the XRCC2 Gene

Oncol Res Treat. 2019;42(5):263-268. doi: 10.1159/000497209. Epub 2019 Mar 12.

Abstract

Background: We aimed to detect single nucleotide polymorphisms (SNPs) and mutations in DNA repair genes and their possible association with myelodysplastic syndrome (MDS).

Methods: Targeted enrichment resequencing of 84 DNA repair genes was initially performed on a screening cohort of MDS patients. Real-time polymerase chain reaction was used for genotyping selected SNPs in the validation cohort of patients.

Results: A heterozygous frameshift mutation in the XRCC2 gene was identified. It leads to the formation of a truncated non-functional protein and decreased XRCC2 expression level. Decreased expression levels of all DNA repair genes functionally connected with mutated XRCC2 were also present. Moreover, a synonymous substitution in the PRKDC gene and 2 missense mutations in the SMUG1 and XRCC1 genes were also found. In the screening cohort, 6 candidate SNPs were associated with the tendency to develop MDS: rs4135113 (TDG, p = 0.03), rs12917 (MGMT, p = 0.003), rs2230641 (CCNH, p = 0.01), rs2228529 and rs2228526 (ERCC6, p = 0.04 and p = 0.03), and rs1799977 (MLH1, p = 0.04). In the validation cohort, only a polymorphism in MLH1 was significantly associated with development of MDS in patients with poor cytogenetics (p = 0.0004).

Conclusion: Our study demonstrates that genetic variants are present in DNA repair genes of MDS patients and may be associated with susceptibility to MDS.

Keywords: DNA repair; Myelodysplastic syndrome; XRCC2.

MeSH terms

  • DNA Mutational Analysis
  • DNA Repair*
  • DNA-Activated Protein Kinase / genetics
  • DNA-Binding Proteins / genetics*
  • Female
  • Genetic Predisposition to Disease
  • Humans
  • Middle Aged
  • MutL Protein Homolog 1 / genetics
  • Mutation*
  • Myelodysplastic Syndromes / enzymology
  • Myelodysplastic Syndromes / genetics*
  • Myelodysplastic Syndromes / metabolism
  • Nuclear Proteins / genetics
  • Polymorphism, Single Nucleotide
  • Uracil-DNA Glycosidase / genetics
  • X-ray Repair Cross Complementing Protein 1 / genetics

Substances

  • DNA-Binding Proteins
  • MLH1 protein, human
  • Nuclear Proteins
  • X-ray Repair Cross Complementing Protein 1
  • XRCC1 protein, human
  • XRCC2 protein, human
  • DNA-Activated Protein Kinase
  • PRKDC protein, human
  • SMUG1 protein, human
  • Uracil-DNA Glycosidase
  • MutL Protein Homolog 1