Several studies have shown an association of heterozygous c.657-661del, p.I171V and p.R215W mutations in the NBN gene with a variety of malignancies but the data are controversial.
Among these, an association with cancer was found most frequently for 657del5 (in leukemia/lymphoma and breast cancer) and I171V (in leukemia, breast, head and neck and colorectal cancers); however, other studies gave contradictory results.
Positive associations have also been reported for leukaemia and larynx cancer suggesting that I171V could be a more general susceptibility factor for malignancies.
Although an increased frequency of both mutations in cancer cases - 0.8% of 657del5 and 2.4% of I171V, compared to controls - 0.52% and 1.38%, respectively, was found, the differences were not statistically significant.