Table 1

Genetic polymorphisms investigated in relation to breast cancer risk

GeneBase changeAmino acid changeDetection methodFunctional effect
Steroid hormone metabolism genes
COMTExon 4 G → AVal158MetCreates Hsp92II and NlaIII sitesReduced activity
CYP17Promoter T → C (T1931C)NoneCreates MspAI siteCreates a fifth Sp1 site and might increase transcription
CYP19Intron 4 (TTTA)u microsatelliteNonePCR fragment sizeUnlikely
Intron 4 TCT insertion/deletionNonePCR fragment sizeUnlikely
CYP2D62367delA (A allele)FrameshiftCreates BsiWI siteNonfunctioning enzyme
Intron 3 G → A (G1934A) (B allele)Premature stop at residue 544Destroys BstNI siteNonfunctioning enzyme
Del Lys281 (C allele)Allele-specific amplificationCatalytically normal enzyme, but wrong cellular compartment
17.5-kb deletion (D allele)Southern blotNo enzyme
EDH17B2Exon 6 A → GSer312GlyCreates BspUI siteUnlikely
ERCCC325CCGPro325ProAllele-specific oligohybridizationNone
Intron 1/exon 2 XbaI siteSouthern blotUnlikely
PRAlu repeat insertion in intron GNonePCR fragment size or creates TaqI siteUnlikely
Carcinogen metabolism genes
CYP1A1Exon 7 A → G (A4889G)Ile462ValCreates NcoI siteUncertain, possible increase in enzyme activity
3′ UTR T → C (T6235C)NoneCreates MspI siteNone
Exon 7 C → A (C4887A)Thr461AspCreates BsaI siteUnknown
3′ UTR T → C (T5639C)NoneCreates MspI siteNone
CYP2E1Intron 6 unspecifiedNoneCreates DraI siteUnlikely
GSTM1Gene deletionAllele-specific PCRNull individuals have no enzyme
GSTP1A313GIle105ValCreates Alu26I siteReduced enzyme activity
GSTT1Gene deletionAllele-specific PCRNull individuals have no enzyme activity
NAT1A1088TNonePossible increase in enzyme activity
NAT2G191ACreates MspI siteLow activity allele
C481TDestroys KpnI siteLow activity allele
G590ADestroys TaqI siteLow activity allele
G857ADestroys BamH1 siteLow activity allele
Other genes
BRCA1C2731TPro871LeuAllele-specific oligohybridizationUnknown
BRCA1G1186AGln356ArgCreates RsaI siteUnknown
HSP70-21267SilentCreates PstI siteUnknown
HSP70-hom2437Met493ThrCreates NcoI siteUnknown
TNF−308 G → ANoneAllele-specific PCRIncreased constitutive and inducible levels TNF-α
TP53Exon 3 G → CArg72ProAllele-specific PCRUnknown
16-bp insertion in intron 3NoneUnlikely
Intron 6 G → ANoneCreates MspI siteUnlikely