RESUMEN
BRCA1 and BRCA2 genes have been recognized to be responsible for 20-30% of hereditary breast cancers and approximately 50% of familial breast and ovarian cancers. Therefore, the demand for BRCA1 and BRCA2 mutation screening is rapidly increasing as their identification will affect medical management of people at increased risk. Because of high costs involved in analysis of BRCA1 and 2 genes, contribution of different mutation types in BRCA1 and 2 and not knowing who should be tested has hampered wide spread use of molecular testing of high -risk families. There is a need to identify the genes and types of mutations involved in breast or ovarian cancers at different age of onsets and polymorphism and polymorphic variations in our population. Twenty-seven patients with either early onset breast cancer [at age