PNCA4 | definition of PNCA4 by Medical dictionary
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symbol for a breast cancer gene. BRCA1 is a tumor suppressor gene. A healthy BRCA1 gene produces a protein that protects against unwanted cell growth. The protein is packaged by the cell's Golgi apparatus into secretory vesicles, which release their contents on the cell's surface. The protein circulates in the intracellular space, attaching itself to neighboring cell receptors. The receptors signal the cell nuclei to stop growing. When the gene is defective, it produces a faulty protein that is unable to prevent proliferation of abnormal cells as they evolve into potentially deadly breast cancer. BRCA1 may also normally inhibit ovarian cancer.
BRCA1 A gene on chromosome 17q21, which encodes a protein that plays a role in maintaining genomic stability and acts as a tumour suppressor. It combines with other tumour suppressors, DNA damage sensors and signal transducers to form a large multi-subunit-protein complex known as the BRCA1-associated genome surveillance complex (BASC), which associates with RNA polymerase II and histone deacetylase complexes, thus playing a role in transcription, DNA repair of double-stranded breaks and recombination. BRCA1 mutations cause 40% of inherited breast cancers and over 80% of inherited breast and ovarian cancers.
BRCA1 Molecular oncology A large tumor suppressor gene on chromosome 17 which is linked to breast, ovarian, prostate and other CAs; Pts with BRCA1 represent 5% of all breast CAs; ♀ with BRCA1 have an 85% chance of developing breast CA before age 65; mutations of BRCA1 are common in Ashkenazi Jews Lab BRCA1 and BRCA2 are part of some commercial diagnostic labs' genetic services. See Tumor suppressor gene.