8.1 Unit Overview
Learning Objectives
- Describe different types and applications of genetic testing
- Discuss ethical and legal protections for genetic testing
- Examine the role of the nurse in working with patient’s receiving genetic testing
- Review genomic variant classification
Outline
Topics covered in this chapter include:
- Genetic testing overview
- Types of Genetic tests
- Genetic tests validity and reliability
- Interpreting genetic test results
Competencies Nurses will Develop in this Chapter
ANA (2023):
Nursing assessment: Applying/integrating genomic knowledge:
- Collects, reviews, and updates personal and family health history to include any genomic testing and environmental and other risk factors.
- Conducts health and physical assessments that incorporate knowledge about known or potential environmental, genomic, and other risk factors (e.g., behavioral, lifestyle).
Identification:
- Identifies credible, accurate, appropriate, and current genomic information, resources, services, and technologies specific to given clients.
- Recognizes issues that undermine the rights of all clients for autonomous, informed genomic-related decision-making and voluntary action.
Provision of education, care, and support:
- Facilitates clients’ access to credible, accurate, appropriate, and current genomic information, resources, services, and technologies.
- Advocates for autonomous, informed genomic-related decision-making.
- Demonstrates in practice the importance of tailoring genomic information and services that are responsive to the unique attributes of every person.
Provision of education, care, and support:
- Performs interventions appropriate to clients’ genomic health care needs.
NHS (2023):
Identify individuals who might benefit from genomic services and/or information as part of assessing needs and planning care:
- recognizing the key indicators of a potential genetic condition, or clinical situation where genomics-informed healthcare would be appropriate;
- recognizing the importance of family history in assessing predisposition to a genetic condition; and
- taking appropriate and timely action to seek assistance from and refer individuals to genomics specialists, other specialists and peer support resources.
Demonstrate effective communication in tailoring genomic information and services to the individual:
- recognizing factors (such as ethnicity, culture, religion, ethical values, developmental stage or language) that may influence the individual’s ability to use information and services.
Demonstrate a knowledge and understanding of genomics in human development, variation and health to underpin effective practice:
- relating it to the maintenance of health and manifestation of conditions;
- relating it to the prevention and management of a genomic condition or response to treatment; and
- underpinned by core genomic concepts that form a sufficient knowledge base for understanding the implications of different conditions and clinical situations that may be encountered.
Apply knowledge, understanding and context of genomic testing and information to underpin care and support for individuals and families prior to, during and following decision-making:
- including types, uses and limitations of genomic tests to prevent, predict or treat a health condition, and an awareness of the processes for testing and return of results;
- recognizing that decision-making and testing in some situations may be time-critical;
- incorporating awareness of the ethical, legal and social issues related to testing, recording, sharing and storage of genomic information and data; and
- incorporating awareness of the potential physical, emotional, psychological and social consequences of genomic information for individuals, family members and communities.
Examine your own competency of practice on a regular basis:
- based on an understanding of the boundaries of your professional role in delivering genomic healthcare including the referral, provision or follow-up to genomic services.
Obtain and communicate reliable, current information about genomics, for self, patients, families and colleagues:
- using information technologies and other information sources effectively to do so; and
- applying critical appraisal skills to assess the quality of information accessed.
Provide ongoing nursing care and support to patients, carers, families and communities with genomic healthcare needs:
- demonstrating awareness about how a genomic test result can have implications for family members and might impact on family dynamics.
Key terminology
Analytical validity
How well a test predicts the presence or absence of a particular gene or genetic change (Medline, 2024).
Carrier screening
Carrier screening involves testing to see if a person “carries” a genetic variation (allele) associated with a specific disease or trait. A carrier has inherited a normal and a variant allele for a disease- or trait-associated gene, one from each parent. Most typically, carrier screening is performed to look for recessively inherited diseases when the suspected carrier has no symptoms of the disease, but that person’s offspring could have the disease if the other parent is a carrier of a harmful variant in the same gene.
Expanded carrier screening refers to reproductive genetic carrier screening beyond one’s ethnicity and family history (GECKO, 2024).
Chromosomal tests:
These tests analyze whole chromosomes or long lengths of DNA to identify large-scale changes, such as an extra or missing copy of a chromosome (trisomy or monosomy, respectively) or abnormalities of large segments of chromosomes, that underlie certain genetic conditions (Medline, 2021a).
Clinical validity
How well the genetic variant being analyzed is related to the presence, absence, or risk of a specific disease (Medline, 2024).
Clinical utility
Whether the test can provide helpful information about diagnosis, treatment, management, or prevention of a disease (Medline, 2024).
Direct-to-consumer testing
Genetic testing that can be ordered by any individual; it is not a clinical test therefore does not need to be ordered by a medical professional.
Exome
An exome is the sequence of all the exons in a genome, reflecting the protein-coding portion of a genome. In humans, the exome is about 1.5% of the genome.
Molecular gene tests:
These tests determine the order of DNA building blocks (nucleotides) in an individual’s genetic code, a process called DNA sequencing. The purpose of these tests is to identify pathogenic genetic variants (Medline, 2021a).
Multigene panels
Look for variants in many genes in the same test (Medline, 2021a).
Newborn screening
Used to test babies one or two days after birth to find out if they have certain diseases known to cause problems with health and development (NHGRI, 2019).
Next-generation DNA sequencing
DNA sequencing establishes the order of the bases that make up DNA. Next-generation DNA sequencing (abbreviated NGS) refers to the use of technologies for sequencing DNA that became available shortly after the completion of the Human Genome Project (which relied on the first-generation method of Sanger sequencing). Faster and cheaper than their predecessors, NGS technologies can sequence an entire human genome in a single day and for less than 1,000.
Pharmacogenomic testing
Provides information about how certain medicines are processed by an individual’s body (NHGRI, 2019).
Predictive/pre-symptomatic genetic test
Used to find gene changes that increase a person’s likelihood of developing diseases. The results of these tests provide information about the risk of developing a specific disease. Such information may be useful in decisions about lifestyle and healthcare (NHGRI, 2019).
Prenatal screening
Is offered during pregnancy to help identify fetuses that have certain diseases (NHGRI, 2019).
Reproductive genetic carrier screening
Facilitates informed decision-making by future parents through identifying those couples at increased risk of having an affected child with a serious genetic disorder (autosomal or X-linked recessive) (GECKO, 2024).
Research genetic testing
Used to learn more about the contributions of genes to health and to disease (NHGRI, 2019).
Sanger sequencing
A method of DNA sequencing that involves electrophoresis and is based on the random incorporation of chain-terminating dideoxynucleotides by DNA polymerase during in vitro DNA replication. After first being developed by Frederick Sanger and colleagues in 1977, it became the most widely used sequencing method for approximately 40 years (Wikipedia, 2024).
Screening (genetic)
Used in people who do not have signs or symptoms of a disorder. These tests estimate whether an individual’s risk of having a certain condition is increased or decreased compared with the risk in other people in a similar population (Medline, 2021a).
Single gene tests
Look for variants in only one gene (monogenic disorder) (Medline, 2021a).
Whole exome sequencing
Looks at all the genes in the DNA (whole exome) or just the genes that are related to medical conditions (clinical exome) (Medline, 2021b).
Whole genome sequencing
Looks at all of a person’s DNA, not just the genes (Medline, 2021b).
Attribution & References
ANA (2023) Nursing Competencies are © American Nurses Association. Reprinted with permission. All rights reserved. Seek permission before reusing this portion of the page.
Except where otherwise noted, this page is adapted from:
- Talking Glossary of Genomic and Genetic Terms, Courtesy of: National Human Genome Research institute (NGHRI), Public Domain with attribution.
References
American Nurses Association (ANA). (2023). Essentials of genomic nursing: Competencies and outcome indicators (3rd ed.). https://www.nursingworld.org/nurses-books/ana-books/ebook-essentials-of-genomic-nursing-competencies-/
Genetics Education Canada Knowledge Organization (GECKO). (2024). Point of care tool: Expanded carrier screening and Reproductive genetic carrier screening: beyond family history and ethnicity. https://www.geneticseducation.ca/resources-for-clinicians/genomic-technologies/expanded-carrier-screening/point-of-care-tool-9
National Health Service (NHS). (2023). The 2023 genomic competency framework for UK nurses. https://www.genomicseducation.hee.nhs.uk/wp-content/uploads/2023/12/2023-Genomic-Competency-Framework-for-UK-Nurses.pdf
National Human Genome Research Institute (NHGRI). (n.d.). Talking glossary of genetic and genomic terms. www.genome.gov
National Human Genome Research Institute (NHGRI). (2019, February 13). Genetic testing FAQ. https://www.genome.gov/FAQ/Genetic-Testing
MedlinePlus. (2021a, July 28). How are genetic screening tests different from genetic diagnostic tests? https://medlineplus.gov/genetics/understanding/testing/differenttests/
MedlinePlus. (2021b, July 28). What are whole exome sequencing and whole genome sequencing? https://medlineplus.gov/genetics/understanding/testing/sequencing/
MedlinePlus. (2024, June 24). How can I be sure a genetic test is valid and useful? https://medlineplus.gov/genetics/understanding/testing/validtest/.
Wikipedia. (2024, September 9). Sanger sequencing. https://en.wikipedia.org/wiki/Sanger_sequencing
