Genetic counseling is the process of investigating individuals and families affected by or at risk of genetic disorders to help them understand and adapt to the medical, psychological and familial implications of genetic contributions to disease. This field is considered necessary for the implementation of genomic medicine. The process integrates:
Genetic testing, also known as DNA testing, is used to identify changes in DNA sequence or chromosome structure. Genetic testing can also include measuring the results of genetic changes, such as RNA analysis as an output of gene expression, or through biochemical analysis to measure specific protein output. In a medical setting, genetic testing can be used to diagnose or rule out suspected genetic disorders, predict risks for specific conditions, or gain information that can be used to customize medical treatments based on an individual's genetic makeup. Genetic testing can also be used to determine biological relatives, such as a child's biological parentage through DNA paternity testing, or be used to broadly predict an individual's ancestry. Genetic testing of plants and animals can be used for similar reasons as in humans, to gain information used for selective breeding, or for efforts to boost genetic diversity in endangered populations.
Medical genetics is the branch of medicine that involves the diagnosis and management of hereditary disorders. Medical genetics differs from human genetics in that human genetics is a field of scientific research that may or may not apply to medicine, while medical genetics refers to the application of genetics to medical care. For example, research on the causes and inheritance of genetic disorders would be considered within both human genetics and medical genetics, while the diagnosis, management, and counselling people with genetic disorders would be considered part of medical genetics.
Mary-Claire King is an American geneticist. She was the first to show that breast cancer can be inherited due to mutations in the gene she called BRCA1. She studies human genetics and is particularly interested in genetic heterogeneity and complex traits. She studies the interaction of genetics and environmental influences and their effects on human conditions such as breast and ovarian cancer, inherited deafness, schizophrenia, HIV, systemic lupus erythematosus and rheumatoid arthritis. She has been the American Cancer Society Professor of the Department of Genome Sciences and of Medical Genetics in the Department of Medicine at the University of Washington since 1995.
Myriad Genetics, Inc. is an American genetic testing and precision medicine company based in Salt Lake City, Utah, United States. Myriad employs a number of proprietary technologies that permit doctors and patients to understand the genetic basis of human disease and the role that genes play in the onset, progression and treatment of disease. This information is used to guide the development of new products that assess an individual's risk for developing disease later in life, identify a patient's likelihood of responding to a particular drug therapy, assess a patient's risk of disease progression and disease recurrence, and measure disease activity.
Predictive medicine is a field of medicine that entails predicting the probability of disease and instituting preventive measures in order to either prevent the disease altogether or significantly decrease its impact upon the patient.
Genomic counseling is the process by which a person gets informed about his or her genome often in the setting of elective genetic and genomic testing. In contrast to genetic counseling, which focuses on Mendelian diseases and typically involves person-to-person communication with a genetic counselor or other medical genetics expert, genomic counseling is not limited to currently clinically relevant information. It is often based on genomic information that is of interest for the informed person, such as increased risk for common complex disease that has actionable components, genetically determined non-disease related traits, or recreational forms of information and genetic genealogy data. An individual's response to certain medications/drugs based on their pharmacogenomic profile may be provided.
The National Society of Genetic Counselors (NSGC), founded and incorporated in 1979, is the largest association of genetic counselors with over 3,600 members. Its membership includes genetic counselors and other healthcare professionals working in the field of medical genetics from the United States, Canada, and around the world.
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, 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.
The Genomic Medicine Institute at the Cleveland Clinic is an inter-disciplinary institute and department that focuses on patient care, patient-oriented research, and outreach and education in personalized healthcare guided by genetics and genomics. It is located in the Center for Genomics Research Building in the Cleveland Clinic, in Cleveland, Ohio, United States of America.
A hereditary cancer syndrome is a genetic disorder in which inherited genetic mutations in one or more genes predispose the affected individuals to the development of cancer and may also cause early onset of these cancers. Hereditary cancer syndromes often show not only a high lifetime risk of developing cancer, but also the development of multiple independent primary tumors.
Henry Thompson Lynch was an American physician noted for his discovery of familial susceptibility to certain kinds of cancer and his research into genetic links to cancer.
Hereditary diffuse gastric cancer (HDGC) is an inherited genetic syndrome most often caused by an inactivating mutation in the E-cadherin gene (CDH1) located on chromosome 16. Individuals who inherit an inactive copy of the CDH1 gene are at significantly elevated risk for developing stomach cancer. For this reason, individuals with these mutations will often elect to undergo prophylactic gastrectomy, or a complete removal of the stomach to prevent this cancer. Mutations in CDH1 are also associated with high risk of lobular breast cancers, and may be associated with a mildly elevated risk of colon cancer.
In genetics, a polygenic score (PGS) is a number that summarizes the estimated effect of many genetic variants on an individual's phenotype. The PGS is also called the polygenic index (PGI) or genome-wide score; in the context of disease risk, it is called a polygenic risk score or genetic risk score. The score reflects an individual's estimated genetic predisposition for a given trait and can be used as a predictor for that trait. It gives an estimate of how likely an individual is to have a given trait based only on genetics, without taking environmental factors into account; and it is typically calculated as a weighted sum of trait-associated alleles.
Color is a population health technology company which provides genetic tests and analysis directly to patients as well as through employers. The product focuses on genes that indicate risk for heart disease, cancer, and that affect medication response.
Elective genetic and genomic testing are DNA tests performed for an individual who does not have an indication for testing. An elective genetic test analyzes selected sites in the human genome while an elective genomic test analyzes the entire human genome. Some elective genetic and genomic tests require a physician to order the test to ensure that individuals understand the risks and benefits of testing as well as the results. Other DNA-based tests, such as a genealogical DNA test do not require a physician's order. Elective testing is generally not paid for by health insurance companies. With the advent of personalized medicine, also called precision medicine, an increasing number of individuals are undertaking elective genetic and genomic testing.
Allison Walsh Kurian is an American medical oncologist. She is a Professor of Medicine and Epidemiology & Population Health at Stanford University and an oncologist at the Stanford Cancer Institute.
Hereditary lobular breast cancer is a rare inherited cancer predisposition associated with pathogenic CDH1 (gene) germline mutations, and without apparent correlation with the hereditary diffuse gastric cancer syndrome. Research studies identified novel CDH1 germline variants in women with diagnosed lobular breast cancer and without any family history of gastric carcinoma. Firstly, in 2018 Giovanni Corso et al. defined this syndrome as a new cancer predisposition and the Authors suggested additional clinical criteria to testing CDH1 in lobular breast cancer patients. In 2020, the International Gastric Cancer Linkage Consortium recognized officially that the hereditary lobular breast cancer is a possible independent syndrome. To date, there are reported about 40 families clustering for lobular breast cancer and associated with CDH1 germline mutations but without association with diffuse gastric cancer. Other recent studies demonstrated a possible correlation between hereditary lobular breast cancer and gastric cancer risk.
Kelly A. Metcalfe is a Canadian scientist and a professor at the University of Toronto and at Women's College Hospital. Her work's focus is on understanding the clinical and psychosocial implications of genetic testing for BRCA gene mutations in women, men and their families.
Jennifer T. Loud is an American nurse practitioner who served as the assistant chief of the National Cancer Institute's clinical genetics branch until August 2020.
