E. Spitzer et al., Detection of BRCA1 and BRCA2 mutations in breast cancer families by a comprehensive two-stage screening procedure, INT J CANC, 85(4), 2000, pp. 474-481
We have developed a 2-stage protocol for BRCA1 and BRCA2 mutation screening
from blood spot paper. Stage screening was aimed to analyze patients at hi
ghest risk for the most common disease-associated sequence variants listed
in the BIC database. Accordingly, stage 1 testing implied detection of 18 d
isease-associated BRCA1 and 9 BRCA2 mutations by adapting the 5' nuclease a
ssay to heterozygote screening. For stage 2 screening, we applied the confo
rmation sensitive gel electrophoresis (CSGE) method by adapting this techni
que to automated heteroduplex analysis of BRCA1 and BRCA2 using fragment sc
anning on an ABI 377 sequencing device. Of the 120 patients with a family h
istory of breast and ovarian cancer who took part in this study so far, 45
entered stage 1 testing. Disease-associated mutations were detected in 6 pa
tients by stage I testing (13%). For these patients, the final result was a
vailable within 10 days, Mutation 300T-->G was found in 2 patients. One pat
ient with mutation 3036delACAA in BRCA2 reported only 1 sister with a multi
focal bilateral breast cancer. New disease-associated mutations were detect
ed in 2 of the 114 patients who entered the stage 2 test (1.7%). Of particu
lar interest was patient who was diagnosed with a medullary breast carcinom
a at age 39 and who had no family history of breast cancer. We conclude tha
t pre-screening by 5' nuclease assay for the mutations most frequently seen
in a given population represents a relatively effective first line of anal
ysis. Subsequent detailed analysis by fluorescence conformation sensitive g
el electrophoresis (F-CSGE) and fragment sequencing is a sensitive alternat
ive to full nucleotide sequencing. Int. J. Cancer 85:474-481, 2000, (C) 200
0 Wiley-Liss, Inc.