Inherited Disorders Testing
What Is Inherited Disorders Testing?
Inherited disorders testing is genetic testing used to identify changes in genes or chromosomes that may be inherited within a family and contribute to a genetic condition. These tests can help determine whether a person has a genetic change associated with an inherited disorder, whether they may have an increased likelihood of developing a condition, or whether they may carry a genetic change that could be passed on to their children.
Testing may focus on a specific genetic change that is already known in a family, one or more genes associated with a particular condition, or a broader group of genes when the underlying cause is not yet clear. The most appropriate test depends on the medical question, the individual’s personal and family history, and the condition being investigated.
Inherited disorders testing can therefore provide information that may help explain certain health conditions, clarify a suspected genetic diagnosis, and inform genetic testing or healthcare decisions for other family members. The results are interpreted in the context of the individual’s clinical and family history rather than in isolation.
What Are Inherited Genetic Disorders?
Inherited genetic disorders are health conditions caused by genetic changes that can be passed from parents to their children. These changes may affect how a gene functions and can sometimes lead to differences in how the body develops or works. Depending on the condition and the specific genetic change involved, an inherited disorder may be present from birth or become apparent later in life.
Inherited disorders can follow different patterns of inheritance. Some are caused by changes in a single gene, while others may involve changes in multiple genes or chromosomes. The way a condition is inherited can also affect who in a family may be at risk and whether other relatives could carry the same genetic change.
Some inherited conditions are relatively well recognised, while others are rare and may be difficult to diagnose based on symptoms alone. A person’s medical history, family history and clinical features can help healthcare professionals determine whether an inherited genetic condition should be considered.
When an inherited condition is suspected, genetic testing can help investigate whether a relevant genetic change is present and may provide information that contributes to diagnosis and family risk assessment.
When Is Testing for an Inherited Disorder Recommended?
Testing for an inherited disorder may be considered when a person's medical or family history suggests that a genetic condition could be present or could be passed on to future generations. The reasons for testing vary depending on the clinical circumstances and the genetic question being investigated.
If a close relative has been diagnosed with an inherited genetic disorder, testing may help determine whether other family members have the same genetic change or may have inherited it. When a specific genetic variant has already been identified in a family, targeted testing can sometimes be used to look specifically for that variant.
Testing may be recommended when a person's symptoms, clinical findings or medical history suggest that an inherited genetic disorder could be contributing to their condition. Genetic testing can help support or clarify a diagnosis when the underlying cause cannot be established through routine clinical investigations alone.
People may also consider testing when planning a family, particularly when there is a personal or family history of an inherited condition. Carrier testing can identify whether a person carries certain genetic changes that could be passed to their children, helping couples understand potential reproductive risks and discuss appropriate options with a healthcare professional.
The decision to test should be based on the specific genetic question. A healthcare professional or genetic counsellor can review your personal and family history and help determine whether inherited disorders testing is appropriate and which type of test may be most informative.
What Can Inherited Disorders Testing Identify?
Inherited disorders testing can investigate genetic changes associated with a wide range of inherited conditions. Depending on the suspected disorder and the clinical question, testing may focus on a specific genetic variant, a single gene, multiple genes, or larger genetic changes involving chromosomes.
These tests may help identify or investigate single-gene disorders, in which a change in one particular gene contributes to a condition, as well as certain chromosomal disorders caused by changes in the number or structure of chromosomes. Examples of inherited conditions include cystic fibrosis, sickle cell disease, Huntington’s disease and some inherited neurological or connective tissue disorders. The appropriate test depends on the condition being considered and the genetic changes known to be associated with it.
Testing can also be tailored to a known genetic change within a family. For example, when a particular variant has already been identified in a relative, targeted testing may determine whether another family member has inherited the same variant. Where the underlying genetic cause is less clear, broader testing such as a multi-gene panel, whole exome sequencing or whole genome sequencing may sometimes be considered.
Because no single genetic test can identify every inherited disorder, the choice of test is based on the person’s symptoms, medical and family history, and the specific genetic question being investigated. A genetic professional can help determine which approach is most appropriate and how the findings should be interpreted.
For inherited conditions that affect specific areas of health, more specialised services may be appropriate, such as Cancer Genetic Testing when an inherited cancer predisposition is suspected.
Which Inherited Disorders Can Be Tested For?
Genetic testing can be used to investigate many different inherited conditions. The appropriate test depends on the suspected disorder, the person's clinical and family history, and the genetic changes known to be associated with the condition.
| Type of Inherited Disorder | Examples | What Testing May Help Determine |
|---|---|---|
| Single-gene disorders | Cystic fibrosis, Huntington's disease and sickle cell disease | Whether a specific genetic change associated with the condition is present |
| Inherited neurological disorders | Certain inherited forms of neurological and neuromuscular disease | Genetic changes that may explain symptoms or an inherited neurological condition |
| Inherited connective tissue disorders | Marfan syndrome and certain inherited connective tissue conditions | Genetic variants associated with the suspected inherited condition |
| Inherited metabolic disorders | Selected inherited disorders affecting metabolism | Genetic changes that may contribute to an inherited metabolic condition |
| Chromosomal disorders | Certain inherited chromosomal conditions | Changes in chromosome number or structure where these are relevant to the clinical question |
Not every inherited disorder is assessed using the same genetic test. Some conditions can be investigated with a targeted test, while others may require a broader analysis of multiple genes or other parts of the genome. The choice of testing approach depends on the suspected condition and the available clinical and genetic information.
Who May Benefit From Inherited Disorders Testing?
Inherited disorders testing may be useful for people in different circumstances, particularly when there is a reason to consider an inherited genetic condition. The potential value of testing depends on the individual’s medical history, family history and the specific genetic question being investigated.
People who may benefit include those with symptoms or clinical findings that could be associated with an inherited condition, particularly when a clear diagnosis has not been established through other investigations. Genetic testing may provide additional information that helps healthcare professionals confirm or clarify a suspected diagnosis.
Testing may also be relevant for people with a known inherited condition or genetic variant in their family. In some circumstances, testing other relatives can help establish whether they have inherited the same genetic change and may inform their own healthcare or family planning decisions.
Children and young people may sometimes be considered for testing when there is a suspected genetic condition that could affect their health during childhood or when knowing the diagnosis could influence their medical care. The timing and appropriateness of testing in children depends on the condition, the potential medical benefit and the circumstances of the individual family.
People who are planning a family may also consider testing when there is a personal or family history of an inherited disorder. Depending on the circumstances, carrier testing can provide information about whether a genetic change could be passed on to children.
Inherited disorders testing is not necessarily appropriate for everyone. A healthcare professional or genetic counsellor can review the relevant medical and family history and help determine whether testing is likely to provide useful information.
How Is Testing for an Inherited Disorder Performed?
Inherited disorders testing follows a structured process that begins with understanding the reason for testing and ends with a clinical interpretation of the results. The exact steps can vary depending on the suspected condition and the type of genetic test being considered.
The process usually begins with a review of your personal and family medical history. Relevant information about relatives, diagnoses, symptoms and patterns of inheritance can help determine whether an inherited condition should be investigated and which type of testing may be appropriate.
Before testing, you may discuss the purpose of the test, what it can and cannot identify, and the possible implications of different results. This can help you make an informed decision about whether testing is appropriate for your circumstances.
If you decide to proceed, an appropriate biological sample is collected, most commonly a blood sample and, for some tests, saliva or another suitable sample. The laboratory then analyses the genetic material using the testing method selected for the clinical question, which may include targeted genetic testing, gene panels or broader genomic analysis.
Once the laboratory analysis is complete, the findings are interpreted in the context of your medical and family history. Depending on the type of test, the result may identify a disease-causing genetic variant, find no relevant variant, or identify a finding whose significance is not yet clear. Your healthcare professional or genetic counsellor can explain the result and discuss appropriate next steps.
The testing process is tailored to the individual. The type of sample, laboratory analysis and interpretation will depend on the condition being investigated and the specific genetic question. Understanding the reason for testing before proceeding helps ensure that the most appropriate approach is considered.
What Happens During Inherited Disorders Testing?
Once the appropriate genetic test has been selected, the testing itself usually involves collecting a biological sample and sending it to a specialist laboratory for analysis. The exact procedure depends on the type of test and the genetic condition being investigated.
Sample Collection
Most inherited disorders tests can be performed using a blood sample, although some tests may use saliva or another suitable biological sample. The sample is collected using the method specified for the particular test and is then prepared for laboratory analysis.
Laboratory Analysis
In the laboratory, DNA is extracted from the sample and analysed for genetic changes relevant to the test. Depending on the clinical question, this may involve looking for a specific known variant, analysing a group of genes, or examining a much broader range of genetic information.
Different laboratory techniques may therefore be used for different situations. A targeted test may be appropriate when a particular genetic change is already suspected, while broader approaches may be considered when the underlying cause is less certain.
Quality Checks and Reporting
Laboratories carry out quality-control procedures during the testing process to help ensure that the sample and analysis meet the required standards. Once the analysis is complete, the relevant genetic findings are documented in a laboratory report for clinical review.
The laboratory report is then considered alongside the person’s medical and family history. This is important because a genetic finding cannot always be understood from the laboratory result alone.
How Are Inherited Disorder Test Results Interpreted?
Inherited disorder test results need to be interpreted in the context of the specific test, the genetic finding identified and the individual’s medical and family history. A result does not always provide a straightforward yes-or-no answer, and the clinical significance of a genetic finding can depend on the condition being investigated.
A positive result may mean that a genetic variant associated with the condition being investigated has been identified. In diagnostic testing, this may help confirm or support a suspected genetic diagnosis. However, the implications of a positive result depend on the particular condition and variant, and do not necessarily mean that a person will develop a condition or experience the same symptoms as another family member.
A negative result means that the test did not identify the genetic change or changes it was designed to detect. This does not necessarily rule out an inherited disorder. Some genetic conditions may involve variants that the particular test cannot detect, or the underlying genetic cause may not yet be known.
A variant of uncertain significance (VUS) is a genetic change for which there is currently insufficient evidence to determine whether it contributes to disease. A VUS should generally not be treated in the same way as a confirmed disease-causing variant, and its classification may change as scientific evidence develops.
Because genetic results can have implications for both the individual and their relatives, professional interpretation is an important part of the testing process. Genetic counselling can help explain what a result means, its limitations, and whether further testing or other clinical follow-up may be appropriate.
What Happens After an Inherited Disorder Is Identified?
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Clinical Review: The genetic finding is considered alongside your symptoms, medical history and family history to establish what the result means in your particular circumstances.
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Genetic Counselling: A genetic counsellor can explain the diagnosis, inheritance pattern and potential implications for you and your relatives, helping you understand the information and available options.
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Family Risk Assessment: Depending on the condition and inheritance pattern, other family members may have an increased likelihood of carrying the same genetic change. Testing or assessment of relatives may be considered where clinically appropriate.
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Ongoing Clinical Care: Some inherited conditions may require specialist monitoring, treatment or other forms of clinical management. The appropriate follow-up depends on the specific condition and the individual's circumstances.
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Support With Future Decisions: Understanding an inherited condition can also provide information relevant to future healthcare and, where appropriate, family planning decisions. Further guidance can help you consider these options based on your individual circumstances.
A genetic diagnosis is often the beginning of a clearer care pathway. The next steps depend on the condition identified, the individual's health and whether other family members may also be affected or at risk.
Inherited Disorders Testing and Genetic Counselling
Inherited disorders testing and genetic counselling are closely connected, but they serve different purposes. Genetic testing analyses DNA to look for genetic changes associated with an inherited condition, while genetic counselling helps individuals and families understand genetic information, potential risks and the implications of testing.
Genetic counselling may take place before testing to help establish whether a genetic test is appropriate and explain what different results could mean. It may also be useful after testing, particularly when a genetic finding has implications for the individual’s health or for other family members.
The two services can therefore work together throughout the testing journey. Counselling can provide context for the genetic information, help individuals understand inheritance patterns and discuss whether relatives may benefit from further assessment or testing.
The need for genetic counselling and the extent of support required will vary depending on the condition being investigated, the type of genetic test and the individual’s personal and family circumstances.
Inherited Disorders Testing for Children and Families
An inherited genetic condition can affect more than one member of a family. When there is a known genetic condition, a relevant family history or clinical features suggesting an inherited disorder, genetic testing may provide useful information for children, parents and other relatives.
Testing is considered on an individual basis. Genetic testing is not automatically appropriate for every child or family member. A review of the medical and family history can help determine who may benefit from testing and when it is appropriate to consider it.
What is inherited disorders testing?
Inherited disorders testing is genetic testing used to identify changes in genes or chromosomes that may be associated with an inherited genetic condition. The type of test depends on the condition being investigated and the individual’s medical and family history.
Who should consider testing for an inherited disorder?
Testing may be considered when a person has symptoms or clinical findings suggestive of an inherited condition, when a known genetic condition or variant is present in the family, or when there is a relevant personal or family history. A healthcare professional can help determine whether testing is appropriate.
What inherited conditions can genetic testing identify?
Depending on the test, genetic testing may identify variants associated with single-gene disorders, inherited neurological or metabolic conditions, connective tissue disorders, and certain chromosomal conditions. The appropriate test depends on the specific clinical question.
How is inherited disorders testing performed?
Most inherited disorder tests are performed using a blood sample, although saliva or other samples may be used for some tests. DNA is analysed in a laboratory using a targeted test, gene panel, or broader genetic analysis, depending on what needs to be investigated.
What does a positive inherited disorder test result mean?
A positive result means that a genetic change relevant to the test has been identified. Its significance depends on the specific variant, the condition being investigated, and the individual’s clinical and family history. A positive result does not necessarily predict exactly how or when a condition will affect a person.
What does a negative inherited disorder test result mean?
A negative result means that the test did not identify a genetic change that it was designed to detect. It does not always completely exclude an inherited condition, as some genetic changes may not be detectable by a particular test.
What is a variant of uncertain significance (VUS)?
A variant of uncertain significance is a genetic change for which there is currently insufficient evidence to determine whether it is associated with a genetic condition. A VUS should not be interpreted in the same way as a confirmed disease-causing variant, and its classification may change as scientific evidence develops.
Can children have inherited disorders testing?
Children may have genetic testing when there is a relevant clinical reason, such as symptoms, a suspected inherited condition, or a known genetic variant in the family. The decision is made on an individual basis, considering the child’s medical circumstances and whether the result may be relevant to their care.
Can other family members have genetic testing if an inherited disorder is identified?
Yes. When a genetic change associated with an inherited condition is identified in one family member, testing may be relevant to other relatives. Which relatives should be considered depends on the condition, inheritance pattern, and the specific genetic finding.
Does having a family history of an inherited disorder mean I need genetic testing?
Not necessarily. A family history may indicate that genetic testing should be considered, but testing is not automatically appropriate for everyone. The relevance of testing depends on the condition in the family, the available genetic information, and the individual’s personal and family history.
Frequently asked questions
In this section you can check frequently asked questions.
Discuss Inherited Disorders Testing With a Specialist
If you have a family history of an inherited condition, symptoms that may have a genetic cause, or a known genetic variant in your family, the next step is to discuss whether genetic testing is appropriate for your circumstances.
At London Genetics, a consultation provides an opportunity to review your personal and family history, discuss the genetic question you would like to investigate, and consider whether testing may be appropriate.
If testing is recommended, the appropriate approach can then be considered based on your individual circumstances. Book a consultation to discuss your situation with a specialist and find out what options may be available to you.
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