Background
Retinoblastoma is a neoplasia that starts in the retina and may have inheritable or sporadic genetic predisposition. This affects children, mainly those who are under 5 years old. Approximately 9,000 new cases are diagnosed per year worldwide. In Ecuador this disease has an incidence of 1 per each 20,000 live births. The genetic predisposition to develop retinoblastoma is strongly influenced by RB1 gene, and may be influenced by the presence of genetic polymorphisms which intervene in the DNA repair system.
Methods
This study has analyzed the genotype frequency of ERCC2 (Lys751Gln), MSH2 (gIVS12-6TC), RAD54 (Ala730Ala), XPC (Lys939Gln), XPG (Asp1104Hist), XRCC1 (Arg399Gln), and XRCC3 (Thr241Met) polymorphisms of different repair genes, genotyping 90 individuals affected with retinoblastoma and 80 healthy individuals through polymerase chain reaction / restriction fragments length polymorphism and sequencing analysis.
Results
The presence of the (C/C) mutant homozygous genotype of XPC (Lys939Gln) polymorphism triggers a significant risk of developing retinoblastoma with an odds ratio (OR) of 3 (CI: 1.22-9.84; p < 0.05). Likewise, the A/G heterozygous genotype and the combination A/G+G/G of XRCC1 (Arg399Gln) polymorphism presented ORs of 9.7 (CI: 4.45-21.08; p < 0.001) and 7.55 (IC: 3.57-16; p < 0.001), respectively.
Conclusions
The genetic variants XPC (Lys939Gln) and XRCC1 (Arg399Gln) may be associated with the risk of developing retinoblastoma in the Ecuadorian population.