Cancer genetics
Introduction
Cancer genetics is the study of genetic mutations, hereditary syndromes, and phenotypic changes that contribute to the development and progression of cancer. This field of study aims to elucidate the cellular mechanisms that lead to uncontrolled cell growth and tumor formation.
Genetic Mutations in Cancer
Genetic mutations in cancer can be broadly classified into two types: germline mutations and somatic mutations.
Germline Mutations
Germline mutations are present in every cell of an organism because they are inherited from a parent. These mutations are present in the egg or sperm cell and are passed on to offspring. Germline mutations that increase the risk of cancer are often implicated in hereditary cancer syndromes.
Somatic Mutations
Somatic mutations, on the other hand, are acquired mutations that occur in a single cell during an individual's lifetime. These mutations can occur due to various factors such as exposure to carcinogens or errors during DNA replication. Somatic mutations can accumulate over time, leading to the development of cancer.
Hereditary Cancer Syndromes
Hereditary cancer syndromes are disorders that increase the risk of developing certain types of cancer. These syndromes are caused by specific germline mutations in certain genes. Some of the most common hereditary cancer syndromes include Hereditary Breast and Ovarian Cancer Syndrome (HBOC), Lynch Syndrome, and Li-Fraumeni Syndrome.
Genomic Instability in Cancer
Genomic instability, characterized by an increased rate of mutation, is a hallmark of cancer. This instability can result from defects in DNA repair mechanisms, such as Mismatch Repair (MMR) and Non-Homologous End Joining (NHEJ).
Cancer Genomics
Cancer genomics is a subfield of cancer genetics that focuses on the comprehensive examination of the cancer genome. This includes the study of gene expression profiles, copy number variations, and other genomic alterations in cancer.
Epigenetic Changes in Cancer
In addition to genetic changes, epigenetic alterations also play a crucial role in cancer development. These changes, which include DNA methylation and histone modification, can affect gene expression without altering the underlying DNA sequence.
Clinical Applications of Cancer Genetics
The study of cancer genetics has numerous clinical applications, including cancer risk assessment, early detection, prognosis, and treatment. Genetic testing can identify individuals at high risk of developing certain types of cancer, allowing for early intervention and potentially preventing cancer development.