Early-onset breast cancer characterize genetic predisposition to cancer in 
women. BRCA-1 gene was identified as one of the predisposition genes of 
breast/ovarian cancer. About 90% of the reported mutations in the hereditary 
breast and ovarian cancer gene, BRCA-1, result in truncated proteins. The aim of 
our study is to detect rapidly BRCA-1 mutations by the protein truncation test 
(PTT) in Tunisian women with early breast cancer. Population and methods. We 
underwent molecular analysis in families with more than: (a) a women under 40 
years-old with breast cancer, uni or bilateral; (b) two 1st degree relatives 
women under 50 years-old with beast cancer. Sixteen women from 12 families were 
studied by PTT to screen mutations in exon 11 which encodes 61% of BRCA-1.
RESULTS: PTT analysis of exon 11 revealed a normal and truncated protein in one 
patient between 16 from 12 families.
CONCLUSION: BRCA-1 gene seems to contribute to at least 1/16 or 6.25% in women 
with hereditary predisposition to breast/ovarian cancer in Tunisia. PTT promises 
to be a valuable technique in detecting BRCA-1 mutations in our country.