Sometimes, having a diagnosis can guide treatment and management decisions. A genetic diagnosis can also suggest whether other family members may be affected by or at risk of a specific disorder.
Full Answer
How is genetic information used to treat disease?
How is genetic information used to treat disease? A person's genetic makeup affects how their body breaks down certain medicines. Genetic testing can examine certain liver enzymes in a person to find out how their body breaks down and removes medicines from the body.
How do genes affect drug response to genetic testing?
Some of the genes tested are related to drug metabolism. These genes can affect drug levels in the blood, but generally don’t predict clinical response.
What do we do with the results of genetic testing?
After learning the test results, help clarify information provided by genetic professionals, explore implications for the patient and family, recommend health promotion and prevention practices based on genetic risk factors, and collaborate with healthcare providers for optimal care delivery.
How does a doctor make a diagnosis of genetic conditions?
A doctor may suspect a diagnosis of a genetic condition on the basis of a person's physical characteristics and family history, or on the results of a screening test. Genetic testing is one of several tools that doctors use to diagnose genetic conditions. The approaches to making a genetic diagnosis include:
How can medication be affected by genetics?
Individuals who do not respond to medications as expected may have genetic differences that change the amount of enzymes available to break down a medication or may cause the enzymes not to work. These genetic differences may have an effect on how someone responds to a medication.
What is genetic diagnosis and treatment?
Genetic testing is a type of medical test that identifies changes in genes, chromosomes, or proteins. The results of a genetic test can confirm or rule out a suspected genetic condition or help determine a person's chance of developing or passing on a genetic disorder.
How can knowing about genetics help treat disease?
How is genetic information used to treat disease? A person's genetic makeup affects how their body breaks down certain medicines. Genetic testing can examine certain liver enzymes in a person to find out how their body breaks down and removes medicines from the body.
How you will diagnose a patient with genetic disease?
Most of the time, genetic disorders are diagnosed through a specific test, which can include examining chromosomes or DNA (the tiny proteins that make up genes), or testing the blood for certain enzymes that may be abnormal. Studying enzymes is called biochemical genetic testing.
What can be diagnosed by genetic testing?
Genetic testing is useful in many areas of medicine and can change the medical care you or your family member receives. For example, genetic testing can provide a diagnosis for a genetic condition such as Fragile X or information about your risk to develop cancer. There are many different kinds of genetic tests.
How do genetics influence health and illness?
Understanding genetic factors and genetic disorders is important in learning more about promoting health and preventing disease. Some genetic changes have been associated with an increased risk of having a child with a birth defect or developmental disability or developing diseases such as cancer or heart disease.
How do genes affect health and disease?
A new copy of your genes is made in every new cell that your body creates throughout your life. If those copies have mistakes, this can cause problems. For example, some gene changes can make you more likely to get cancer. Your environment can also directly cause changes to DNA inside your cells.
Which is an example of how genetics affect health?
Genetic variations can have large or small effects on the likelihood of developing a particular disease. For example, certain variants (also called mutations) in the BRCA1 or BRCA2 genes greatly increase a person's risk of developing breast cancer and ovarian cancer.
How to treat genetic disorders?
For example, a genetic disorder associated with a heart defect might be treated with surgery to repair the defect or with a heart transplant. Conditions that are characterized by defective blood cell formation, such as sickle cell disease, can sometimes be treated with a bone marrow transplant. Bone marrow transplantation can allow the formation of normal blood cells and, if done early in life, may help prevent episodes of pain and other future complications.
What is gene therapy?
This experimental technique involves changing a person's genes to prevent or treat a disease. Gene therapy, along with many other treatment and management approaches for genetic conditions, are under study in clinical trials.
What are the inborn errors of metabolism?
For a group of genetic conditions called inborn errors of metabolism, which result from genetic changes that disrupt the production of specific enzymes, treatments sometimes include dietary changes or replacement of the particular enzyme that is missing. Limiting certain substances in the diet can help prevent the buildup ...
What are some examples of genetic changes?
One well-known example is familial breast cancer related to mutations in the BRCA1 and BRCA2 genes.
Can genetic disorders be cured?
As a result, these disorders often affect many body systems, and most cannot be cured. However, approaches may be available to treat or manage some of the associated signs and symptoms.
Can sickle cell disease be treated with bone marrow?
Conditions that are characterized by defective blood cell formation, such as sickle cell disease, can sometimes be treated with a bone marrow transplant. Bone marrow transplantation can allow the formation ...
Can genetic disorders cause miscarriage?
Genetic disorders may cause such severe health problems that they are incompatible with life. In the most severe cases, these conditions may cause a miscarriage of an affected embryo or fetus. In other cases, affected infants may be stillborn or die shortly after birth.
What tests are used to diagnose genetic disorders?
Laboratory tests, including genetic testing: Molecular, chromosomal, and biochemical genetic or genomic testing are used to diagnose genetic disorders. Other laboratory tests that measure the levels of certain substances in blood and urine can also help suggest a diagnosis.
What is genetic testing?
Genetic testing is one of several tools that doctors use to diagnose genetic conditions. The approaches to making a genetic diagnosis include: A physical examination: Certain physical characteristics, such as distinctive facial features, can suggest the diagnosis of a genetic disorder.
What is personal medical history?
Personal medical history: Information about an individual's health, often going back to birth, can provide clues to a genetic diagnosis. A personal medical history includes past health issues, hospitalizations and surgeries , allergies, medications, and the results of any medical or genetic testing that has already been done.
What does a genetic counselor ask about?
A doctor or genetic counselor will ask about health conditions in an individual's parents, siblings, children, and possibly more distant relatives. This information can give clues about the diagnosis and inheritance pattern of a genetic condition in a family.
When can you get a genetic diagnosis?
A diagnosis of a genetic disorder can be made anytime during life, from before birth to old age, depending on when the features of the condition appear and the availability of testing. Sometimes, having a diagnosis can guide treatment and management decisions.
Is genetic testing available?
Genetic testing is currently available for many genetic conditions. However, some conditions do not have a genetic test; either the genetic cause of the condition is unknown or a test has not yet been developed. In these cases, sequencing the entire genome may result in locating the responsible genetic variant.
Why is genetic testing not right for me?
Some reasons might be that it’s not relevant to you or won’t change your medical care, it’s too expensive, and the results may make you worried or anxious.
What is a clinical genetic test?
Clinical genetic tests are different from direct-to-consumer (DTC) genetic tests, which can give some information about medical and non-medical traits. Clinical genetic tests are ordered by your doctor for a specific medical reason. DTC tests are usually purchased by healthy individuals who are interested in learning more about traits like ancestry, responses to medications, or risk for developing certain complex conditions. DTC test results can be used to make decisions about lifestyle choices or provide issues to discuss with your doctor. However, DTC tests cannot definitely determine whether or not you will get a disease and should not be used alone for decisions about your treatment or medical care.
What is Genetic Testing?
Genetic testing looks for changes, sometimes called mutations or variants, in your DNA. Genetic testing is useful in many areas of medicine and can change the medical care you or your family member receives. For example, genetic testing can provide a diagnosis for a genetic condition such as Fragile X or information about your risk to develop cancer. There are many different kinds of genetic tests. Genetic tests are done using a blood or spit sample and results are usually ready in a few weeks. Because we share DNA with our family members, if you are found to have a genetic change, your family members may have the same change. Genetic counseling before and after genetic testing can help make sure that you are the right person in your family to get a genetic test, you’re getting the right genetic test, and that you understand your results.
What is single gene testing?
Single gene tests look for changes in only one gene. Single gene testing is done when your doctor believes you or your child have symptoms of a specific condition or syndrome. Some examples of this are Duchene muscular dystrophy or sickle cell disease. Single gene testing is also used when there is a known genetic mutation in a family.
What are some examples of genetic panel tests?
Some examples of genetic panel tests are low muscle tone, short stature, or epilepsy. Panel genetic tests can also be grouped into genes that are all associated with higher risk of developing certain kinds of cancer, like breast or colorectal (colon) cancer. Large-scale genetic or genomic testing. There are two different kinds ...
How long does it take for a genetic test to be done?
There are many different kinds of genetic tests. Genetic tests are done using a blood or spit sample and results are usually ready in a few weeks. Because we share DNA with our family members, if you are found to have a genetic change, your family members may have the same change.
What is the name of the test that looks at all the genes in the DNA?
external icon. looks at all the genes in the DNA (whole exome) or just the genes that are related to medical conditions (clinical exome). Genome sequencing. external icon. is the largest genetic test and looks at all of a person’s DNA, not just the genes.
How to assess genetic risk?
To assess a patient’s genetic risk, you must understand the relationship of genetics and genomics to health, prevention, screening, treatment, and monitoring. Essential nursing competencies include basic knowledge of genetic and genomic principles, genetic resources, current research, and professional guidelines and recommendations. Consider genetic, environmental, and genomic influences and risks during physical assessments, when collecting personal and family health histories, and when analyzing this information. In addition, assess the patient’s knowledge and perceptions of genetic and genomic information, as well as his or her responses, and address any issues or concerns. In developing the care plan in conjunction with the patient, integrate clinical judgment, patient preferences, evidence-based research, and family implications to plan genetic- and genomic-focused care.
What do nurses need to know about genetics?
Nurses need the skills to gather family history, identify hereditary risk, and make appropriate referrals for genetic consultation and testing. During the genetic assessment process nurses can help patients understand ...
What are the standards for genetics in nursing?
The initial Scope and Standards for Clinical Genetics Nursing Practice was first published in 1998 after the American Nurses Association (ANA) recognized genetics as a nursing specialty. Then, shortly after completion of human genome sequencing, ANA published the Essentials of Genetic and Genomic Nursing: Competencies, Curricular Guidelines, and Outcome Indicators, which was endorsed by 47 nursing organizations. These guidelines challenge nurses to: 1 recognize how their personal attitudes about genetics might impact their practice 2 advocate for clients for genetic services and autonomous genetic decision-making 3 incorporate genetic and genomic information into their practices and regularly evaluate their competency 4 tailor genetic and genomic information to patients based on their culture, literacy, religion, and preferred language.
How is pharmacogenomics used in medicine?
Pharmacogenomics, the study of how a person metabolizes medications based on his or her personal genetic makeup, is one of the earliest applications of genetic and genomic research into clinical intervention. (See Genetic markers for drug response and function .) Pharmacogenomics has been most commonly used in psychiatry to determine drug choice and response, and in pain management to assess addiction potential. In addition, genetic testing can be used to tailor medication management to reduce and minimize side effects and promote treatment plan adherence.
Why is pharmacogenomics used in psychiatry?
Pharmacogenomics has been most commonly used in psychiatry to determine drug choice and response, and in pain management to assess addiction potential. In addition, genetic testing can be used to tailor medication management to reduce and minimize side effects and promote treatment plan adherence.
What is precision medicine?
Precision medicine (tailoring medical treatment to each patient’s individual characteristics) has become an important component of nursing practice. Research supports precision medicine as an evolving strategy for disease treatment and prevention that includes attention to an individual’s variability in genes, environment, and lifestyle.
When was clinical genetics first published?
The initial Scope and Standards for Clinical Genetics Nursing Practice was first published in 1998 after the American Nurses Association (ANA) recognized genetics as a nursing specialty.
How do genetics contribute to disease risk?
For more than 100 years, human geneticists have been studying how variations in genes contribute to variations in disease risk. These studies have taken two approaches. The first approach focuses on identifying the individual genes with variations that give rise to simple Mendelian patterns of disease inheritance (e.g., autosomal dominant, autosomal recessive, and X-linked) (see Table 3-1; Mendelian Inheritance in Man). The second approach seeks to understand the genetic susceptibility to disease as the con sequence of the joint effects of many genes. Each of these approaches will be discussed below.
How do we analyze genetic variation?
Analysis of the effects of genetic variation typically involves first the discovery of single nucleotide polymorphisms (SNPs)1and then the analysis of these variations in samples from populations. SNPs occur on average approximately every 500 to 2,000 bases in the human genome. The most common approach to SNP discovery is to sequence the gene of interest in a representative sample of individuals. Currently, sequencing of entire genes on small numbers of individuals (~25 to 50) can detect polymorphisms occurring in 1 to 3 percent of the population with approximately 95 percent confidence. The Human DNA Polymorphism Discovery Program of the National Institute of Environmental Health Sciences’ Environmental Genome Project is one example of the application of automated DNA sequencing technologies to identify SNPs in human genes that may be associated with disease susceptibility and response to environment (Livingston et al., 2004). The National Heart, Lung, and Blood Institute’s Programs in Genomic Applications also has led to important increases in our knowledge about the distribution of SNPs in key genes thought to be already biologically implicated in disease risk (i.e., biological candidate genes2).
How is CVD studied?
The study of CVD can be used to illustrate the issues that are encountered in using genetic information in order to understand the etiology of the most common chronic diseases as well as in identifying those at highest risk of developing these diseases. The majority of CVD cases have a complex multifactorial etiology, and even full knowledge of an individual’s genetic makeup cannot predict with certainty the onset, progression, or severity of disease (Sing et al., 2003). Disease develops as a consequence of interactions between a person’s genotype and exposures to environmental agents, which influence cardiovascular phenotypes beginning at conception and continuing throughout adulthood. CVD research has found many high-risk environmental agents and hundreds of genes, each with many variations that are thought to influence disease risk. As the number of interacting agents involved increases, a smaller number of cases of disease will be found to have the same etiology and be associated with a particular genotype (Sing et al., 2003). The many feedback mechanisms and interactions of agents from the genome through intermediate biochemical and physiological subsystems with exposure to environmental agents contribute to the emergence of a given individual’s clinical phenotype. In attempting to sort out the relative contributions of genes and environment to CVD, a large array of factors must be considered, from the influence of genes on cholesterol (e.g., LDL levels) to psychosocial factors such as stress and anger. Although hundreds of genes have been implicated in the initiation, progression, and clinical manifestation of CVD, relatively little is known about how a person’s environment interacts with these genes to tip the balance between the atherogenic and anti-atherogenic processes that result in clinically manifested CVD. Please see Chapters 4and 6for further discussion of effects of social environment on CVD.
What are some examples of Mendelian inheritance?
Another example of Mendelian inheritance is familial forms of breast cancer associated with mutations in the BRCA1 and BRCA2 genes that predispose women to early onset breast cancer and often ovarian cancer. The genes identified have mutations that often are highly penetrant—that is, the probability of developing the disease in someone carrying the disease susceptibility genotype is relatively high (greater than 50 percent). These genetic diseases often exhibit a genetic phenomenon known asallelic heterogeneity,in which multiple mutations within the same gene (i.e., alleles) are found to be associated with the same disease. This allelic heterogeneity often is population specific and can represent the unique demographic and mutational history of the population.
How many genes are there in the human genome?
The human genome is made up of tens of thousands of genes. With approximately 30,000 genes to choose from, assigning a specific gene or group of genes to a corresponding human disease demands a methodical approach consisting of many steps. Traditionally, the process of gene discovery begins with a linkage analysis that assesses disease within families. Linkage analyses are typically followed by genetic association studies that assess disease across families or across unrelated individuals.
What is etiologic heterogeneity?
Etiologic heterogeneity refers to a phenomenon that occurs in the general population when multiple groups of disease cases, such as breast cancer clusters, exhibit similar clinical features, but are in fact the result of differing events or exposures. Insight into the etiology of specific diseases as well as identification of possible causative agents is facilitated by discovery and examination of disease cases demonstrating etiologic heterogeneity. The results of these studies may also highlight possible gene-gene interactions and gene-environment interactions important in the disease process. Identifying etiologic heterogeneity can be an important step toward analysis of diseases using molecular epidemiology techniques and may eventually lead to improved disease prevention strategies (Rebbeck et al., 1997).
Why are twin studies important?
Twin studies comparing the disease and risk factor variability of monozygotic and dizygotic twins have been a common study design used to easily estimate both genetic and cultural inheritance. Studies of monozygotic twins reared together versus those reared apart also have been important in estimating both genetic and environmental contributions to patterns of inheritance. The modeling of the sources of phenotypic variation using family studies has become quite sophisticated, allowing the inclusion of model parameters to represent the additive genetic component (i.e., polygenes), the nonadditive genetic component (i.e., genetic dominance, as well as gene-environment and gene-gene interactions), shared family environment, and individual environments. The contributions of these factors have been shown to vary by age and population.
Why did patients not respond well to genetic testing?
Notably, many patients had not responded well before entering a study because they were receiving inappropriate treatments. They improved when switched to more standard treatments. However, the same changes would have been made without guidance from the test if the treating clinicians had simply followed good practice, rather than getting an unproven and expensive genetic test. And our ongoing review of newer studies on these tests suggests similar flaws and no further evidence favoring their use.
Why are gene tests so appealing?
Genetic testing is appealing, both to vulnerable patients and time-constrained doctors. And it is vigorously marketed to both parties by the companies that sell it: through news reports, websites, television, and magazines, and to doctors in their offices. There are few restraints that hold that marketing to the facts, yet the facts are clear in evidence summarized by numerous experts and agencies. Currently available genetic test panels have no proven value for choosing antidepressant treatment, and their use risks providing inappropriate care. So, while gene testing can be very useful for some other conditions, notably some cancer treatments, that success does not yet apply in treating depression. Perhaps this will change with more research, but appropriate tests are years away.
How do genes affect depression?
Genes determine some of our risk for depression and some of our response to treatment. However, no single gene or small number of genes determines much of either in the general population. And the few genes used in the current commercial test panels do not appear to be the key genes determining risk or response. Some of the genes tested are related to drug metabolism. These genes can affect drug levels in the blood, but generally don’t predict clinical response. Other factors, including age, diet, hormonal state, gut bacteria, and any other concurrently taken drugs, are far more important in determining how a person metabolizes a drug and responds to treatment.
What to do if your medication is not working?
You and your doctor can. review your symptoms and diagnosis. review side effects of other medications you take to see if this is part of the problem. double-check that you are taking the medications correctly.
Do gene tests help with depression?
Currently, there is no scientific evidence that gene tests are needed or would be helpful as part of those assessments.
Do gene tests show effectiveness?
Even with that bias, the use of gene results showed no evidence of effectiveness. A few studies were partially blinded, but doctors and patients still knew some patients got a special test. In these studies, too, the tests failed to show value on their key measures of efficacy.
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What Is Genetic Testing?
Reasons For Genetic Testing
- To learn whether you have a genetic condition that runs in your family before you have symptoms
- To learn about the chance a current or future pregnancy will have a genetic condition
- To diagnose a genetic condition if you or your child has symptoms
- To understand and guide your cancer prevention or treatment plan
Types of Genetic Tests
- There are many different kinds of genetic tests. There is no single genetic test that can detect all genetic conditions. The approach to genetic testing is individualized based on your medical and family history and what condition you’re being tested for. Single genetesting. Single gene tests look for changes in only one gene. Single gene testing is done when your doctor believes you or …
Testing For Changes Other Than Gene Changes
- Chromosomes. DNA is packaged into structures called chromosomes. Some tests look for changes in chromosomes rather than gene changes. Examples of these tests are karyotype and chromosomal microarrays.
- Gene expression. Genes are expressed, or turned on, at different levels in different types of cells. Gene expression tests compare these levels between normal cells and diseased cells b…
- Chromosomes. DNA is packaged into structures called chromosomes. Some tests look for changes in chromosomes rather than gene changes. Examples of these tests are karyotype and chromosomal microarrays.
- Gene expression. Genes are expressed, or turned on, at different levels in different types of cells. Gene expression tests compare these levels between normal cells and diseased cells because knowi...
Types of Genetic Test Results
- Positive– the test found a genetic change known to cause disease.
- Negative– the test did not find a genetic change known to cause disease. Sometimes a negative result occurs when the wrong test was ordered or there isn’t a genetic cause for that person’s symptoms...
- Uncertain– a variant of unknown or uncertain significance means there isn’t enough informat…
- Positive– the test found a genetic change known to cause disease.
- Negative– the test did not find a genetic change known to cause disease. Sometimes a negative result occurs when the wrong test was ordered or there isn’t a genetic cause for that person’s symptoms...
- Uncertain– a variant of unknown or uncertain significance means there isn’t enough information about that genetic change to determine whether it is benign (normal) or pathogenic (disease causing).
Next Steps
- If you have a family historyof a genetic condition, have symptoms of a genetic condition, or are interesting in learning about your chance of having a genetic condition, talk to your doctor about whether genetic testing is right for you.