Table 1

SNPs selected for the study and their functional consequences.

SNPs
Minor Allele (%)
Interacting SNPs*
Alteration
Function
Breast Cancer Association§
Selected Biological Processes¶

Higher Rank (Direct Functional Evidence)

XPD-[Lys751Gln]
C: 32.3
Yes
Missense
Gln (C) allele has decreased DNA repair capacity [15-18]
Yes [83]
transcription-coupled nucleotide-excision repair, ATP-dependent DNA helicase activity
COMT-[Met108/158Val]
G: 47.3
Yes
Missense
Met (A) allele has lower enzymatic activity [20,21]
Yes [84]
neurotransmitter catabolism, catecholamine metabolism
GSTP1-[Ile105Val]
G: 31.2
Yes
Missense
Val (G) allele is associated with reduced enzymatic activity [22,23]
Yes [85]
Metabolism, glutathione transferase activity
MTHFR-[Ala222Val]
T: 35.6
No
Missense
Val (T) allele is associated with reduced enzyme activity [19]
Yes† [86]
Folate metabolism, methylene-tetrahydrofolate reductase (NADPH) activity
CCND1-[Pro241Pro]
A: 46.1
Yes
Splice Variant
(A) allele affects protein stability [24-27]
Yes [87]
G1/S transition of mitotic cell cycle
MMP1-[1G(-1607)2G]
Ins: 49.7
No
Regulatory
(Ins) allele shows increased transcription [28,29]
No
collagen catabolism, interstitial collagenase activity
IL10-[G(-1082)A]
G: 47.6
Yes
Regulatory
G allele is associated with increased expression [30-32]
No
cell-cell signaling, B-cell differentiation and proliferation, anti-apoptosis.

Medium Rank (Indirect Functional Evidence)

BARD1-[Pro24Ser]
T: 37.5
Yes
Missense
Proline to serine change is a significant alteration
No
response to DNA damage, protein ubiquitination, regulation of apoptosis
IL13-[Arg130Gln]
A : 18.3
No
Missense
Gln allele associated with increased IgE levels [41]
No
immune response, inflammatory response, signal transduction,
p27-[Val109Gly]
G: 19.4
No
Missense
Possible function [33]
No
regulation of cyclin dependent protein kinase activity
GSTM3-[4595 (3bp ins/del)]
Del: 16.8
No
UTR
creates recognition site for transcription factor YY1 [34]
No
Metabolism, glutathione transferase activity
TNFA-[G(-308)A]
A: 17.6
No
UTR
increased transcriptional activity; also no functional change [35-38]
No
inflammatory response, signal transduction, regulation of transcription, apoptosis
CYP17-[C(518)T]
C: 34.3
No
Regulatory
Associated with increased serum estradiol [39,40]
Yes [4]
C21-Steroid hormone metabolism,

Lower Rank (No Functional Evidence)

IL1A-[Ala114Ser]
T : 27.4
No
Missense
no published functional evidence
No
MAPK signaling pathway, regulation of progression through cell cycle
GADD45-[C(IVS3+168)T]
C: 31.2
No
Intronic
no published functional evidence
No
regulation of cyclin dependent protein kinase activity, DNA repair, apoptosis
PTEN-[(IVS4+109)ins/del5
Ins: 30.1
No
Intronic
no published functional evidence
No
negative regulation of cell cycle, protein tyrosine/serine/threonine phosphatase activity
ESR1-[Ser10Ser]
C: 48.5
No
Silent
no published functional evidence
No
steroid hormone receptor activity, signal transduction, regulation of transcription
G-CSF-[Leu185Leu]
G: 38
No
Silent
no published functional evidence
No
immune response, cell-cell signaling, positive regulation of cell proliferation
ESR1-[Pro325Pro]
G: 24.1
No
Silent
no published functional evidence
No
steroid hormone receptor activity, signal transduction, regulation of transcription

*No and Yes indicates whether the SNP has been shown to be "interacting" or "not interacting" with other SNPs in this study; § The studies that showed statistically significant overall SNP-disease risk associations were considered (Ncases > 250 and Ncontrols > 250).

†Cases are women diagnosed with breast cancer before age 40; ¶ GeneCards [88]

Onay et al. BMC Cancer 2006 6:114   doi:10.1186/1471-2407-6-114