Personal genomics (consumer genetics)

Personal genomics, also known as consumer genetics or direct-to-consumer (DTC) genetics, is the practice of individuals sequencing their own genomes. Made possible following the 2003 functional completion of the Human Genome Project, personal genomics began to develop during the mid-2000s but was initially restricted by high costs. Later breakthroughs in deoxyribonucleic acid (DNA) sequencing technologies dramatically lowered the costs involved in personal genomics, prompting its introduction to consumer markets in the 2010s.

Consumers can use personal genomics to learn about their ancestry, health profile, and physiology. Personal genomics also has extensive practical applications in genetic disease predictions and diagnoses, and in screening aspiring parents for the presence of genes they could pass on to their children as genetic diseases such as cystic fibrosis. Personal genomics also anchors an initiative known as the Personal Genome Project, which was launched at Harvard University in 2005 with the objective of collecting and studying the personal genomes of at least 100,000 people. Despite offering many considerable advantages, especially in healthcare and medicine, personal genomics is also fraught with ethical and privacy considerations that experts urge consumers to carefully consider before electing to participate in it.

Background

In genetics, a genome is the complete set of DNA instructions contained within a single cell in a biological organism. DNA is a cellular molecule that contains the genetic information that governs the development and function of most organisms. The human genome consists of twenty-three pairs of chromosomes, which are string-like structures that house lengthy strands of DNA. The twenty-three chromosomal pairs are found in the nucleus of each human cell, and join with a single smaller chromosome located in a cellular structure known as the mitochondria to create the complete human genome.

In 1990, a cooperative team of international genetics researchers began work on the Human Genome Project, which endeavored to sequence the entire human genome and publish the data for free and open use by other scientists. Genetic sequencing is a laboratory technique used to identify the precise type of genetic information encoded within a specific DNA segment. Researchers completed their work on the Human Genome Project in 2003, resulting in the successful mapping of approximately 92 percent of the human genome. Scientists later developed advanced techniques for mapping the remaining 8 percent of the human genome, with the final results being issued in a series of six scientific papers published in the peer-reviewed academic journal Science in 2022.

Individual human beings display very little genetic difference from one another, with the Smithsonian Institution citing variations between individuals of about 0.1 percent. Yet, at the same time, every person has a wholly unique genome. Each person’s unique genetic profile may potentially contain a wealth of important insights about their ancestral origins, proneness to certain diseases, and potential to pass on certain specific hereditary characteristics to their children, among other types of unique information.

Shortly after the Human Genome Project functionally concluded in 2003, genetics researchers began investigating the applications of personal genomics in greater detail. Apple co-founder Steve Jobs famously became one of the first people in history to have their entire personal genome sequenced. Jobs reportedly paid $100,000 to complete this process, which was prohibitively expensive for most people in the 2000s. Notably, Jobs also had researchers complete the genetic sequencing of the cancer that ultimately claimed his life in 2011.

By the early 2010s, the costs associated with sequencing individual human genomes had decreased dramatically, making the practice financially accessible to a much broader base of potential consumers. Private enterprises then emerged, offering genetic testing kits to individuals on a direct-to-consumer basis. Initially, these kits did not yield a complete genome sequence and instead focused only on the genetic information that tends to vary among individuals. However, by the mid-2010s, further cost reductions in the sequencing process made it feasible for private service providers to produce the fullest possible genome profiles. This has since become a widely used standard in the consumer genetics industry.

Overview

Consumer genomics companies typically provide clients with self-testing kits, which the client uses to submit a sample of their own genetic material. Samples usually consist of saliva, which is collected in a specialized receptacle and returned to the company for analysis. During the analysis process, laboratory technicians build the consumer’s individual genetic profile with particular attention paid to their unique DNA variations.

Personal genomics can be used to provide consumers with information about their ancestry as indicated by their DNA profiles. This application was widely used in early marketing efforts and continues to attract consumers to the industry, but advocates stress that consumer genetics has many other arguably more important applications with health and wellness implications. These include screening individuals for their susceptibility to diseases with genetic components, assessing the likelihood of a parent or parents passing on potential genetic conditions to their children, and insights into which types of drug treatments and medications best suit the individual.

Consumer genetics can both confirm the presence of a genetic disease as well as predict a person’s likelihood of developing a disease that has known genetic markers. For instance, a consumer might choose to have their genes analyzed to determine the profiles of their BRCA1 and BRCA2 genes. Both of these genes protect people from developing certain forms of cancer, including breast and ovarian cancers. However, the presence of certain mutations on the BRCA1 and BRCA2 genes inhibit their proper function, indicating an increased likelihood that the person carrying the mutations may develop the cancers these genes normally protect against.

Couples can also use consumer genetics as a way to screen themselves for the potential presence of genetic conditions their children could inherit. For example, genetic testing can determine whether one or both parents are carrying genes associated with cystic fibrosis or other potentially serious genetic diseases. Parents who discover the presence of transmissible genetic defects can then elect to consider alternatives to natural conception, such as in vitro fertilization that facilitates the pre-screening of an embryo for genetic diseases before it becomes implanted in the mother’s womb. In other cases, couples may even rethink their decision to have children altogether.

Personal genomics also has useful applications in an emerging area known as pharmacogenomics, which involves genetic profiling to determine how a person will respond to particular medications. This technique can indicate which medication(s) a patient is most likely to respond to, and which are most likely to cause undesirable side effects.

Consumer genetics carries both advantages and drawbacks, some of which relate specifically to prevailing testing methods while others are more general in nature. With respect to the self-testing kits typically issued to consumers, key advantages include convenience, ease of use, and affordability. These kits make it easier for people to adopt proactive approaches to using genetics technology to manage their long-term health. However, the results they generate are not always 100 percent accurate. Self-testing kits can generate both false positives and false negatives with respect to genetic markers and conditions, which can result from errors made by consumers during the sampling process, incorrect analysis of lab results, or other factors.

More broadly, direct-to-consumer genetics testing has functioned to raise public awareness of genetics, genetic conditions, and their potential health impacts and the transmissibility of genetic conditions to offspring. The personalized information personal genomics provides can deliver deep and valuable insights with applications beyond healthcare and medicine to include an individual’s personal history. Individual genetic profiles can be anonymously added to research databases, allowing consumers to contribute to potentially important future genetics breakthroughs.

The general downsides of personal genomics broadly relate to accuracy and privacy concerns. In some cases, individuals may make critical decisions about the management and treatment of diseases or conditions based on information or test results that were inaccurate, incomplete, misleading, or misinterpreted. Because most personal genomics profiling is performed outside of clinical settings, clients cannot receive genetic counseling from an accredited healthcare professional unless they choose to share their results. However, the decision to share results can carry consequences for consumers, as the results of genetic tests may impact an individual’s ability to obtain certain types of insurance including life insurance, long-term care insurance, or disability insurance.

Many private companies provide personal genomics services with relatively little oversight, which creates significant privacy concerns. Companies may misuse client data or share it without the client’s active consent or knowledge, and genetic data can also be intercepted or stolen by third parties for criminal purposes. Consumers who undergo genetic testing to learn more about their ancestry may also discover upsetting or distressing information about themselves or their predecessors. For example, a person may inadvertently discover that they were fathered and/or mothered by someone other than the person they believed to be their biological parent(s).

Bibliography

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“Genetic Evidence.” Smithsonian National Museum of Natural History, 15 Aug. 2022, humanorigins.si.edu/evidence/genetics. Accessed 15 Mar. 2023.

“How Accurate Are DNA Self-Test Kits?” Cleveland Clinic, 15 Jun. 2018, health.clevelandclinic.org/how-accurate-are-dna-self-testing-kits/. Accessed 15 Mar. 2023.

Marshall, Michael. “Why the Human Genome Was Never Completed.” BBC, 13 Feb. 2023, www.bbc.com/future/article/20230210-the-man-whose-genome-you-can-read-end-to-end. Accessed 15 Mar. 2023.

“Personal Genomics: The Future of Healthcare?” Wellcome Genome Campus, 21 July 2021, www.yourgenome.org/stories/personal-genomics-the-future-of-healthcare/. Accessed 15 Mar. 2023.

“The BRCA1 and BRCA2 Genes.” Centers for Disease Control and Prevention, 25 Mar. 2020, www.cdc.gov/genomics/disease/breast‗ovarian‗cancer/genes‗hboc.htm. Accessed 15 Mar. 2023.

Wan, Zhiyu, et. al. “Sociotechnical Safeguards for Genomic Data Privacy.” Nature Reviews Genetics, Vol. 23 (2022): pp. 429–445.

“What Are the Benefits and Risks of Direct-to-Consumer Genetic Testing?” Medline Plus, 21 Jun. 2022, medlineplus.gov/genetics/understanding/dtcgenetictesting/dtcrisksbenefits/. Accessed 15 Mar. 2023.

“What Is Consumer Genetics?” Personal Genetics Education Project, 2018, pged.org/direct-to-consumer-genetic-testing/. Accessed 15 Mar. 2023.