<Table> <Tr> <Td_colspan="2"> View / Edit Human </Td> <Td_colspan="2"> View / Edit Mouse </Td> </Tr> </Table> <Tr> <Td_colspan="2"> View / Edit Human </Td> <Td_colspan="2"> View / Edit Mouse </Td> </Tr> <P> BRCA1 and BRCA1 (/ ˌbrækəˈwʌn /) are a human gene and its protein product, respectively . The official symbol (BRCA1, italic for the gene, nonitalic for the protein) and the official name (breast cancer 1) are maintained by the HGNC . Orthologs, styled Brca1 and Brca1, are common in other mammal species . BRCA1 is a human tumor suppressor gene (to be specific, a caretaker gene), found in all humans; its protein, also called by the synonym breast cancer type 1 susceptibility protein, is responsible for repairing DNA . </P> <P> BRCA1 and BRCA2 are normally expressed in the cells of breast and other tissue, where they help repair damaged DNA, or destroy cells if DNA cannot be repaired . They are involved in the repair of chromosomal damage with an important role in the error - free repair of DNA double - strand breaks . If BRCA1 or BRCA2 itself is damaged by a BRCA mutation, damaged DNA is not repaired properly, and this increases the risk for breast cancer . BRCA1 and BRCA2 have been described as "breast cancer susceptibility genes" and "breast cancer susceptibility proteins". The predominate allele has a normal, tumor suppressive function whereas high penetrance mutations in these genes cause a loss of tumor suppressive function which correlates with an increased risk of breast cancer . </P>

What type of cancer is associated with the brac1 gene