title: Frequency of CHEK2*1100delC in New York breast cancer cases and controls.
abstract: BACKGROUND
  The 1100delC CHEK2 allele has been associated with a 1.4-4.7 fold increased risk for breast cancer in women carrying this mutation. While the frequency of 1100delC was 1.1-1.4% in healthy Finnish controls, the frequency of this allele in a North American control population and in North American breast cancer kindreds remains unclear.
  
  
  METHODS
  We genotyped 1665 healthy New York volunteers and 300 cases of breast cancer for the CHEK2*1100delC.
  
  
  RESULTS
  The overall frequency of the 1100delC was 3/300 (1.0%) among all cases with either a family history of breast cancer (n = 192) or a personal history of breast cancer (n = 108, of which 46 were bilateral, 46 unilateral, and 16 were male breast cancer cases), compared to a frequency of 5/1665 (0.3%) in healthy controls (p = 0.1). There was no difference in allele frequency among Ashkenazi and non-Ashkenazi controls.
  
  
  CONCLUSIONS
  The relatively low breast cancer penetrance of this allele, along with the low population frequency, will limit the clinical applicability of germline testing for CHEK2*1100delC in North American kindreds.
authors.affiliation: Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY, USA. offitk@mskcc.org
authors.forename: Kenneth
authors.initials: K
authors.lastname: Offit
authors.forename: Heather
authors.initials: H
authors.lastname: Pierce
authors.forename: Tomas
authors.initials: T
authors.lastname: Kirchhoff
authors.forename: Prema
authors.initials: P
authors.lastname: Kolachana
authors.forename: Beth
authors.initials: B
authors.lastname: Rapaport
authors.forename: Peter
authors.initials: P
authors.lastname: Gregersen
authors.forename: Steven
authors.initials: S
authors.lastname: Johnson
authors.forename: Orit
authors.initials: O
authors.lastname: Yossepowitch
authors.forename: Helen
authors.initials: H
authors.lastname: Huang
authors.forename: Jaya
authors.initials: J
authors.lastname: Satagopan
authors.forename: Mark
authors.initials: M
authors.lastname: Robson
authors.forename: Lauren
authors.initials: L
authors.lastname: Scheuer
authors.forename: Khedoudja
authors.initials: K
authors.lastname: Nafa
authors.forename: Nathan
authors.initials: N
authors.lastname: Ellis
mesh_terms: D000483:Alleles; D001943:Breast Neoplasms / Q000453:epidemiology / Q000208:ethnology / Q000235:genetics*; D018567:Breast Neoplasms, Male / Q000453:epidemiology / Q000208:ethnology / Q000235:genetics; D064447:Checkpoint Kinase 2; D003596:Cytosine; D005260:Female; D005787:Gene Frequency / Q000235:genetics*; D005838:Genotype; D006801:Humans; D007585:Jews / Q000235:genetics; D008297:Male; D009518:New York / Q000453:epidemiology; D017354:Point Mutation / Q000235:genetics*; D011494:Protein Kinases / Q000235:genetics*; D017346:Protein Serine-Threonine Kinases; D017384:Sequence Deletion / Q000235:genetics*
chemical_list: D003596:Cytosine; D011494:Protein Kinases; D064447:Checkpoint Kinase 2; C578634:CHEK2 protein, human; D017346:Protein Serine-Threonine Kinases