Frequency of germ-line BRCA1 mutations among Spanish families from a Mediterranean area.

We have carried out a study of breast cancer in Spanish families in which the entire coding region of the BRCA1 gene have been analyzed. To identify BRCA1 mutations, PTT and CSGE methods were used followed by direct sequencing. We investigated 51 breast cancer women with a family history. Among these we have identified 7 frameshifts mutations (15%), 185delAG (4 times), 1623del5 and 3450del4 (2 times), and 3 missense mutations, Ser1613Gly, Met1652Ile and Ala1708Glu, which are likely polymorphisms. These findings show that BRCA1 is implicated in a fraction of Spanish familial breast cancer similar to other countries. There was association between bilateral breast cancer and BRCA1 mutations. The CSGE technique has been demonstrated to be a highly reliable method for mutation screening because of its sensitivity and high throughput.