Frequency of BRCA1 mutation 5382insC in German breast cancer patients

Objective. The aim of the study was to determine the frequency of the BRCA1 mutation 5382insC in German breast cancer patients with and without prior knowledge of a family history of breast cancer. Methods. Two groups of breast cancer patients were tested for the presence or absence of the 5382insC mutation using a PCR primer mismatch assay. A sample of 248 patients unrelated by genealogy was selected based on a history of breast and/or ovarian cancer in the families. In addition, a population-based sample of 800 unselected breast cancer patients was included in the analysis. Three intragenic DNA markers D17S1323, D17S1322, and D17S855, located at BRCA1 introns 12, 19, and 20, respectively, were utilized for allelic association studies as well as for haplotype analysis in 4 breast/ovarian cancer families. Results. The 5382insC mutation was identified in 10/248 (4.0%) familial breast cancer patients and in 8/800 (1.0%) unselected cases. Allelic association studies and haplotype analysis revealed an association of allele Nos. "6" at D17S1323 (chi(2) value = 9.34, P = 0.007), "5" at D17S1322 (chi(2) value = 3.62, P = 0.171), and "4" at D17S855 (chi(2) value = 11.34, P = 0.002) with the mutation 5382insC. Conclusion. 5382insC constitutes a frequent BRCA1 mutation in German breast cancer patients. The significant allelic association between this mutation and two intragenic DNA markers (D17S1323, D17S855) and the elevated allele frequency at marker D17S1322 suggest an ancient founder in the German breast cancer population. The PCR primer mismatch assay described herein provides a rapid and reliable detection method for the recurrent 5382insC mutation and will be useful for the analysis of large breast cancer populations. (C) 1999 Academic Press.