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Possible locations for breast cancer susceptibility genes identified
Reuters Health
Posting Date: June 21, 2006
Last Updated: 2006-06-21 13:30:30 -0400 (Reuters Health)
NEW YORK (Reuters Health) - A genome-wide linkage search for breast cancer susceptibility genes has helped define possible areas of interest, but has not identified any specific genes, a large international group of researchers report in the June 21st issue of Genes, Chromosomes and Cancer.
Mutations in the known BRCA1 and BRCA2 breast cancer susceptibility genes account for only a minority of the familial aggregation of the disease, Dr. Douglas F. Easton of Cambridge University, UK and colleagues note.
To search for additional susceptibility genes, the researchers studied 149 families that each had at least three members diagnosed with breast cancer before the age of 60 years. At least one of the subjects in each family was tested and found not to carry a BRCA1 or BRCA2 mutation.
The researchers used the logarithm of odds (lods), a method to unify linkage tests, to evaluate the subjects. Lod scores greater than 1 were found in four regions. The maximum lod score of 2.40 was located on chromosome arm 2p in families with four or more cases of breast cancer diagnosed before the age of 50 years.
However, the team adds that the number of linkage peaks did not differ from that expected by chance. The results suggest promising regions for the location of breast cancer susceptibility genes, but "no single gene is likely to account for a large fraction of the familial aggregation of breast cancer that is not due to mutations in BRCA1 or BRCA2."
Genes Chromosomes Cancer 2006;45:646-655.
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