A BRCA mutation is a mutation in either of the BRCA1 and BRCA2 genes, which are tumour suppressor genes. Hundreds of different types of mutations in these genes have been identified, some of which have been determined to be harmful, while others have no proven impact. Harmful mutations in these genes may produce a hereditary breast–ovarian cancer syndrome in affected persons. Only 5–10% of breast cancer cases in women are attributed to BRCA1 and BRCA2 mutations (with BRCA1 mutations being slightly more common than BRCA2 mutations), but the impact on women with the gene mutation is more profound. Women with harmful mutations in either BRCA1 or BRCA2 have a risk of breast cancer that is about five times the normal risk, and a risk of ovarian cancer that is about ten to thirty times normal. The risk of breast and ovarian cancer is higher for women with a high-risk BRCA1 mutation than with a BRCA2 mutation. Having a high-risk mutation does not guarantee that the woman will develop any type of cancer, or imply that any cancer that appears was actually caused by the mutation, rather than some other factor.
High-risk mutations, which disable an important error-free DNA repair process (homology directed repair), significantly increase the person's risk of developing breast cancer, ovarian cancer and certain other cancers. Why BRCA1 and BRCA2 mutations lead preferentially to cancers of the breast and ovary is not known, but lack of BRCA1 function seems to lead to non-functional X-chromosome inactivation. Not all mutations are high-risk; some appear to be harmless variations. The cancer risk associated with any given mutation varies significantly and depends on the exact type and location of the mutation and possibly other individual factors.
Mutations can be inherited from either parent and may be passed on to both sons and daughters. Each child of a genetic carrier, regardless of sex, has a 50% chance of inheriting the mutated gene from the parent who carries the mutation.
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This course provides a comprehensive overview of the biology of cancer, illustrating the mechanisms that cancer cells use to grow and disseminate at the expense of normal tissues and organs.
The course covers in detail molecular mechanisms of cancer development with emphasis on cell cycle control, genome stability, oncogenes and tumor suppressor genes.
CHEK2 (Checkpoint kinase 2) is a tumor suppressor gene that encodes the protein CHK2, a serine-threonine kinase. CHK2 is involved in DNA repair, cell cycle arrest or apoptosis in response to DNA damage. Mutations to the CHEK2 gene have been linked to a wide range of cancers. The CHEK2 gene is located on the long (q) arm of chromosome 22 at position 12.1. Its location on chromosome 22 stretches from base pair 28,687,742 to base pair 28,741,904. The CHEK2 protein encoded by the CHEK2 gene is a serine threonine kinase.
Les dépistages ont une très grande importance dans la prévention de certains cancers. Ils permettent un diagnostic plus précoce de la tumeur et par conséquent, la mortalité, les douleurs, et les traitements parfois lourds, tels que les chimiothérapies, peuvent parfois ainsi être évités ou réduits. Le plus souvent, ce n'est pas la douleur qui permet de déceler un cancer : une tumeur n'est en elle-même pas douloureuse. C'est un groupement anarchique de cellules inorganisées.
Prophylactic surgery (also known as preventive surgery or risk-reducing surgery), is a form of surgery whose purpose is to minimize or prevent the risk of developing cancer in an organ or gland that has yet to develop cancer and is known to be at high risk of developing cancer. This form of preventive healthcare may include surgeries such as mastectomies, oophorectomies, colectomies and surgical corrections, such as the surgical correction of cryptorchidism or undescended testis.
Explore les gènes suppresseurs de tumeurs dans les cancers humains, en se concentrant sur la prédisposition génétique au rétinoblastome et les mutations du gène RB.
Background: Cancer genome sequencing enables accurate classification of tumours and tumour subtypes. However, prediction performance is still limited using exome-only sequencing and for tumour types with low somatic mutation burden such as many paediatri ...
BRCA2 and RAD51 are two proteins that play a central role in homologous recombination (HR) and DNA double strand break (DSB) repair. BRCA2 assists RAD51 fibrillation and defibrillation through binding with its eight BRC repeats, with BRC4 being one of the ...
Breast carcinoma is the most prevalent cancer among women globally. It has variable clinical courses depending on the stage and clinical-biological features. This case report describes a 56-year-old female with invasive breast cancer without estrogen or pr ...