rs117039649, also known as SNP285 or SNP285C, is a SNP in an intron of the MDM2 p53 binding protein homolog gene.
This SNP appears to only be found (so far) in Caucasians, and, in a subset of the alleles carrying the SNP309G>C (rs2279744) variant.
A 2011 study comparing MDM2 promoter status among different cohorts of ovarian cancer (n = 1993) and breast cancer (n = 1973) patients concluded that rs117039649(C) carriers were at reduced risk for both ovarian (odds ratio 0.74, CI: 0.58-0.94) and breast (odds ratio 0.79, CI: 0.62-1.00) cancer compared to SNP309G carriers (lacking SNP285).[PMID 21316605]
[PMID 26224627] Murine Double-Minute 2 Homolog Single Nucleotide Polymorphisms 285 and 309 in Cervical Carcinogenesis
[PMID 27624283] MDM2 promoter SNP55 (rs2870820) affects risk of colon cancer but not breast-, lung-, or prostate cancer.