Background: Recent reports revealed a significant association of NBN polymorphisms with risk of acute leukemia among Chinese, but not among Europeans. The objective of this study was to obtain a more precise measure of acute leukemia risk associated with NBN rs1805794, rs2735383, rs709816 polymorphisms.
Methods: Using PubMed, Embase, ISI Web of Science, and the Cochrane Library databases, we undertook a systematic literature search up to September 1, 2014. Eligible studies were singled out from 31 possibly related publications by two investigators. Based on the extracted NBN genotypes, we calculated pooled odds ratios (ORs) and 95% confidence intervals (95% CI) by use of the random effects model proposed by DerSimonian and Laird.
Results: We finally derived 3,065 subjects for meta-analysis of rs1805794, and found that carriage of the CC genotype was associated with approximately 1.70-fold increased risk of acute leukemia (OR 1.66, 95% CI 1.17-2.36; OR 1.77, 95% CI 1.23-2.54). A 25% higher risk was also identified among the individuals with the C allele (OR 1.25, 95% CI 1.03-1.51). Among 1,553 subjects for rs2735383, no significant association was indicated in the investigated comparison models. Nor did the analysis of 1,485 samples for rs709816 suggest any noteworthy connection.
Conclusions: Carriage of rs1805794 polymorphism in the NBN gene may be associated with the occurrence of acute leukemia. New clinical studies are needed to identify the genetic associations and thus facilitates an increased understanding of the molecular mechanisms of this malignancy.
Keywords: Nibrin; acute leukemia; polymorphisms.