Two ATM variants and breast cancer risk.
The ATM gene is mutated in ataxia-telangiectasia (AT). Heterozygote female relatives of AT cases have a 2-7fold increased risk of breast cancer. We previously reported high risks of breast cancer associated with certain ATM variants. To estimate the risks more precisely, we have examined two ATM variants, c.1066-6T>G (IVS10-6T>G) and c.4258C>T (p.Leu1420Phe), in additional cases and controls from the same Australian cohorts previously used to estimate the risk of breast cancer associated with c.1066-6T>G. A total of 775 and 84 population-based controls were genotyped for the c.1066-6T>G and c.4258C>T ATM variants respectively, as were index cases from 378 and 373 non-BRCA1/2 breast cancer families. Penetrance was estimated by Bayes factor analysis. The allele frequencies of ATM c.1066-6T>G and c.4258C>T estimated from controls were 0.005 (95% CI=0.002 to 0.009) and 0.012 (95% CI=0.001 to 0.042), respectively. We identified three new breast cancer families with c.1066-6T>G, and seven families with c.4258C>T. Combining with the two c.1066-6T>G families previously reported, the estimated penetrance to age 70 of c.1066-6T>G was 17.2% (95% CI=4.7% to 37.5%). For c.4258C>T, the estimated average penetrance was 4.8% (95% CI 1.7% to 10.1%). In conclusion, we found no evidence that the ATM c.4258C>T variant increases breast cancer risk, and little evidence that c.1066-6T>G confers an elevated risk. Analysis of additional families will be necessary to define more precisely the risk, if any, associated with c.1066-6T>G.
Thompson
Deborah
D
Cancer Research United Kingdom Genetic Epidemiology Unit, University of Cambridge, Cambridge, United Kingdom.
Antoniou
Antonis C
AC
Jenkins
Mark
M
Marsh
Anna
A
Chen
Xiaoqing
X
Wayne
Tierney
T
Tesoriero
Andrea
A
Milne
Roger
R
Spurdle
Amanda
A
Thorstenson
Yvonne
Y
Southey
Melissa
M
Giles
Graham G
GG
Khanna
Kum Kum
KK
Sambrook
Joseph
J
Oefner
Peter
P
Goldgar
David
D
Hopper
John L
JL
Easton
Doug
D
Chenevix-Trench
Georgia
G
D064007:Ataxia Telangiectasia Mutated Proteins; D001499:Bayes Theorem; D001943:Breast Neoplasms / Q000235:genetics*; D018797:Cell Cycle Proteins / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D005091:Exons / Q000235:genetics; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006720:Homozygote; D006801:Humans; D009154:Mutation / Q000235:genetics*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D025521:Tumor Suppressor Proteins / Q000235:genetics*
D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D025521:Tumor Suppressor Proteins; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D017346:Protein Serine-Threonine Kinases