A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosomal abnormality. Although polygenic disorders are the most common, the term is mostly used when discussing disorders with a single genetic cause, either in a gene or chromosome. The mutation responsible can occur spontaneously before embryonic development, or it can be inherited from two parents who are carriers of a faulty gene or from a parent with the disorder. When the genetic disorder is inherited from one or both parents, it is also classified as a hereditary disease. Some disorders are caused by a mutation on the X chromosome and have X-linked inheritance. Very few disorders are inherited on the Y chromosome or mitochondrial DNA.
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.
Invitae Corp. is a biotechnology company that was created as a subsidiary of Genomic Health in 2010 and then spun-off in 2012.
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.
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.
The exome is composed of all of the exons within the genome, the sequences which, when transcribed, remain within the mature RNA after introns are removed by RNA splicing. This includes untranslated regions of messenger RNA (mRNA), and coding regions. Exome sequencing has proven to be an efficient method of determining the genetic basis of more than two dozen Mendelian or single gene disorders.
Exome sequencing, also known as whole exome sequencing (WES), is a genomic technique for sequencing all of the protein-coding regions of genes in a genome. It consists of two steps: the first step is to select only the subset of DNA that encodes proteins. These regions are known as exons—humans have about 180,000 exons, constituting about 1% of the human genome, or approximately 30 million base pairs. The second step is to sequence the exonic DNA using any high-throughput DNA sequencing technology.
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.
On 29 March 2010, the US District Court for the Southern District of New York found several of the patent claims on the BRCA1 and BRCA2 breast cancer genes held by Myriad Genetics to be invalid. The patents were initially issued on the basis that the genes were isolated and purified to a non-naturally occurring state, however the court found, amongst other things, that the purification was not markedly different from a product of nature and thus was not patentable. The ruling may have implications for holders of other gene patents and the patentability of other naturally occurring substances. It has the potential to directly affect the operation of the healthcare and medical research industries, particularly with regards to cancer treatment and prevention, and may alter the accessibility of such therapies to patients.
Gene by Gene is a commercial genetic testing company based in Houston, Texas. The company was owned by Bennett Greenspan and Max Blankfeld, and was the parent company of Family Tree DNA. In January 2021, Gene by Gene was acquired by US based parent company myDNA Inc. Gene by Gene and Australia company myDNA Life Private Ltd. are both subsidiaries of parent company, myDNA Inc. The current Chief Executive Officer of myDNA Inc. is, Dr Lior Rauchberger.
Molecular diagnostics is a collection of techniques used to analyze biological markers in the genome and proteome, and how their cells express their genes as proteins, applying molecular biology to medical testing. In medicine the technique is used to diagnose and monitor disease, detect risk, and decide which therapies will work best for individual patients, and in agricultural biosecurity similarly to monitor crop- and livestock disease, estimate risk, and decide what quarantine measures must be taken.
GATC Biotech was a German company specialist in DNA and RNA sequencing for academic and industrial partners worldwide. The company offered sequencing and bioinformatics solutions from single samples up to large-scale projects. 'The Genome and Diagnostic Centre' focusing on next and third-generation sequencing was based in the headquarters in Constance, Germany. The fully automated NGS laboratories were certified under ISO 17025. The Sanger sequencing business was located in 'The European Custom Sequencing Centre' in Cologne, Germany. The proximity to Cologne Bonn Cargo GmbH served as the logistical hub within Europe. GATC Biotech was acquired by Eurofins Genomics in July 2017.
The genotype-first approach is a type of strategy used in genetic epidemiological studies to associate specific genotypes to apparent clinical phenotypes of a complex disease or trait. As opposed to “phenotype-first”, the traditional strategy that has been guiding genome-wide association studies (GWAS) so far, this approach characterizes individuals first by a statistically common genotype based on molecular tests prior to clinical phenotypic classification. This method of grouping leads to patient evaluations based on a shared genetic etiology for the observed phenotypes, regardless of their suspected diagnosis. Thus, this approach can prevent initial phenotypic bias and allow for identification of genes that pose a significant contribution to the disease etiology.
A variant of uncertainsignificance (VUS) is a genetic variant that has been identified through genetic testing but whose significance to the function or health of an organism is not known. Two related terms are "gene of uncertain significance" (GUS), which refers to a gene that has been identified through genome sequencing but whose connection to a human disease has not been established, and "insignificant mutation", referring to a gene variant that has no impact on the health or function of an organism. The term "variant' is favored in clinical practice over "mutation" because it can be used to describe an allele more precisely. When the variant has no impact on health, it is called a "benign variant". When it is associated with a disease, it is called a "pathogenic variant". A "pharmacogenomic variant" has an effect only when an individual takes a particular drug and therefore is neither benign nor pathogenic.
Association for Molecular Pathology v. Myriad Genetics, Inc., 569 U.S. 576 (2013), was a Supreme Court case, which decided that "a naturally occurring DNA segment is a product of nature and not patent eligible merely because it has been isolated.” However, as a "bizarre conciliatory prize" the Court allowed patenting of complementary DNA, which contains exactly the same protein-coding base pair sequence as the natural DNA, albeit with introns removed.
Wendy K. Chung is an American clinical and molecular geneticist and physician. She is the Chair of the Department of Pediatrics at Boston Children's Hospital and is on the faculty at Harvard Medical School. She is the author of 700 peer-reviewed articles and 75 chapters and has won several awards as a physician, researcher, and professor. Chung helped to initiate a new form of newborn screening for spinal muscular atrophy which is used nationally and was among the plaintiffs in the Supreme Court case which banned gene patenting.
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.
Personalized genomics is the human genetics-derived study of analyzing and interpreting individualized genetic information by genome sequencing to identify genetic variations compared to the library of known sequences. International genetics communities have spared no effort from the past and have gradually cooperated to prosecute research projects to determine DNA sequences of the human genome using DNA sequencing techniques. The methods that are the most commonly used are whole exome sequencing and whole genome sequencing. Both approaches are used to identify genetic variations. Genome sequencing became more cost-effective over time, and made it applicable in the medical field, allowing scientists to understand which genes are attributed to specific diseases.
Salt and pepper developmental regression syndrome, also known as Amish infantile epileptic syndrome or GM3 deficiency syndrome, is a rare autosomal recessive progressive neurological disorder characterized by developmental delay, severe intellectual disability, seizures, and skin pigmentation irregularities. The clinical symptoms of this condition start manifesting soon after birth, during the newborn/neo-natal stage of life.
