Cascade testing is the process of informing family members of a genetic condition discovered within the family, followed by family members getting tested for the condition. Many people do not know they have a genetic condition until symptoms of that condition begin to affect their lives. By then, treatments might be less likely to work. Cascade testing offers one way of finding people with genetic conditions before they show symptoms, allowing them to take steps to prevent disease or treat it early.

How Does Cascade Testing Work?

If you have been diagnosed with a genetic condition, your family members are more likely to have it, too. Sharing your diagnosis with your family members allows them to learn more and be checked for the condition. Finding and treating a genetic condition early can lead to better health.

Family members who are most likely to have the same genetic change, or mutation, are tested first. From there, genetic testing “cascades” through the family depending on who has the genetic change and who does not. For example, if genetic testing shows that your mother has the same genetic change that you have, family members on your mother’s side would be tested. Your father’s side would not need to be tested.

How to Share Your Diagnosis with Your Family Members

The first step in cascade testing is to let your family members know about your diagnosis and genetic test results. Here are some tips to getting started:

1. Gather information to share with your family members. This may include the following:
   • Your diagnosis
   • Your genetic test report(s): Providing a copy of your genetic test report for your family members to take to a genetic counselor may help your family members receive testing quicker.
   • Your lab results related to the condition (such as blood work): Some genetic conditions, such as familial hypercholesterolemia, can be diagnosed without genetic testing.
2. Determine which family members should be tested first. A genetic counselor or medical provider can help you with this.
   • Your children, sisters, brothers, and parents are most likely to have the same genetic condition. Testing should start with them, with the limitation that genetic testing for adult-onset conditions is not generally done in children.
   • If a family member is not available for testing (for example, the family member does not want to be tested or has died), then moving to more distant family members is appropriate.
3. Decide how you would like to share the information with your family members. Some options:
   • Talk to your family members directly. Your genetic counselor can help you plan how to tell your family members, including what information is most important.
   • Write a letter explaining your diagnosis, including any related genetic testing and lab results. Sample letters are available for hereditary breast and ovarian cancer, Lynch Syndrome, and familial hypercholesterolemia.
   • Ask a family member to help you tell other members in your family. If you are unsure of how to contact certain family members, having another family member contact them may help you get the information out to more family members.
   • Ask family members to attend a genetic counseling or doctor’s appointment with you. If you are unsure or concerned about how to describe the condition to your family, a genetic counselor or doctor can assist. In addition, your doctor or genetic counselor might be able to provide a family letter explaining your diagnosis. Sample letters are available for hereditary breast and ovarian cancer and Lynch syndrome.

What if My Family Members Do Not Want to Talk about Hereditary Conditions and Cascade Testing?

Talking about having an increased risk of developing cancer, heart disease, or other hereditary conditions may be difficult for some family members. Before talking to family members about their risk of having the same genetic change, it could be helpful to anticipate possible reactions. For example, if you think that a family member might get emotional from learning this information, it might be best to tell them about this in a comfortable, private area.

If a family member refuses to talk about this information, it is important to respect their decision. Some people do not want to know about their risks for developing certain diseases because it will cause them too much anxiety. However, you can offer them other options, so they can get the information on their own terms. For example, you can provide them information on how to talk to a genetic counselor or give them a letter that they can open whenever they are ready. Sample letters are available for hereditary breast and ovarian cancer, Lynch Syndrome, and familial hypercholesterolemia.

How Do I Talk to My Children?

The process of talking to children about hereditary conditions may differ from talking to adult family members. Your children’s immediate concern might be how the condition will affect your health and the impact that will have on them. Your child’s age may affect how you talk to them about your condition and their chances of having it. For younger children, it may be helpful to tell them smaller pieces of information over time to allow them time to process the information you share. Older children may want to learn all the information in one conversation, and then want to talk to a medical provider about their own health risks. A genetic counselor can help you plan how to tell your children about your condition and their risks, and provide information on when your children should get genetic testing.

Next Steps for Family Members

After sharing this information with your family members, they may ask you what they should do. Below are some tips to help your family members get checked for the genetic condition:

1. Your family members can get genetic counseling. A genetic counselor can help your family members order genetic tests. You can contact your genetic counselor for help, or you can find other genetic counselors using the National Society of Genetic Counselors directory. Genetic counselors are available through in-person and telehealth appointments.
2. Encourage your family members to tell their doctors about your diagnosis. Their doctors can help them determine the best management plan.

Important Topics to Discuss:

Family members may have some concerns after you share this information with them. You and your family members might want to talk to a medical provider or genetic counselor about the following:

• Genetic testing may be free: Some genetic testing companies offer free cascade testing for family members. Contact your genetic counselor or doctor who ordered your testing to see if your family members qualify. In some cases, free testing is only available for a certain amount of time after a family member’s genetic test.
• Insurance Protections: Genetic test results are protected under the Genetic Information Non-discrimination Act (GINA). This legislation prohibits health insurance companies and employers from discriminating against an individual based on their genetic information. However, GINA does not protect individuals from discrimination by life, disability, or long-term care insurance companies.
• Community Support: You and your family members might find it helpful to connect with others with the same genetic condition. One way to do this is through online support groups such as Kintalk, FORCE (Cancer), the Family Heart Foundation (familial hypercholesterolemia), and Genetic Alliance (rare genetic disorders). Your genetic counselor may have additional resources to help you and your family connect to other families. The Disease Info Search database includes information on support groups for several different genetic conditions.

What is family health history?

Family health history is a record of the diseases and health conditions in your family. You and your family members share genes. You may also have behaviors in common, such as exercise habits and what you like to eat. You may live in the same area and come into contact with similar things in the environment. Family history includes all of these factors, any of which can affect your health.

How can I collect my family health history?

You may know a lot about your family health history or only a little. To get the complete picture, use family gatherings as a time to talk about health history. If possible, look at death certificates and family medical records. Collect information about your parents, sisters, brothers, half-sisters, half-brothers, children, grandparents, aunts, uncles, nieces, and nephews. Include information on major medical conditions, causes of death, age at disease diagnosis, age at death, and ethnic background. Be sure to update the information regularly and share what you’ve learned with your family and with your doctor.

Why is family health history important for my health?

Most people have a family health history of at least one chronic disease, such as cancer, heart disease, and diabetes. If you have a close family member with a chronic disease, you may be more likely to develop that disease yourself, especially if more than one close relative has (or had) the disease or a family member got the disease at a younger age than usual.

Collect your family health history information before visiting the doctor, and take it with you. Even if you don’t know all of your family health history information, share what you do know. Family health history information, even if incomplete, can help your doctor decide which screening tests you need and when those tests should start.

How can I use my family health history to improve my health?

You can’t change your genes, but you can change unhealthy behaviors, such as smoking, not exercising or being active, and poor eating habits. If you have a family health history of disease, you may have the most to gain from lifestyle changes and screening tests. In many cases, adopting a healthier lifestyle can reduce your risk for diseases that run in your family. Screening tests, such as diabetes screening, mammograms, and colorectal cancer screening, help find early signs of disease. Finding disease early can often mean better health in the long run.

When a genetic disorder is diagnosed in a family, family members often want to know the likelihood that they or their children will develop the condition. This can be difficult to predict in some cases because many factors influence a person's chances of developing a genetic condition. One important factor is how the condition is inherited. For example:

• Autosomal dominant inheritance: A person affected by an autosomal dominant disorder has a 50 percent chance of passing the altered gene to each child. The chance that a child will not inherit the altered gene is also 50 percent. However, in some cases an autosomal dominant disorder results from a new (de novo) variant that occurs during the formation of egg or sperm cells or early in embryonic development. In these cases, the child's parents are unaffected, but the child may pass on the condition to his or her own children.

• Autosomal recessive inheritance: Two unaffected people who each carry one copy of the altered gene for an autosomal recessive disorder (carriers) have a 25 percent chance with each pregnancy of having a child affected by the disorder. The chance with each pregnancy of having an unaffected child who is a carrier of the disorder is 50 percent, and the chance that a child will not have the disorder and will not be a carrier is 25 percent. If only one parent is a carrier of the altered gene and the other parent does not carry the variant, none of their children will develop the condition, and the chance with each pregnancy of having an unaffected child who is a carrier is 50 percent.

• X-linked dominant inheritance: The chance of passing on an X-linked dominant condition differs between men and women because men have one X chromosome and one Y chromosome, while women have two X chromosomes. A man passes on his Y chromosome to all of his sons and his X chromosome to all of his daughters. Therefore, the sons of a man with an X-linked dominant disorder will not be affected, but all of his daughters will inherit the condition. A woman passes on one or the other of her X chromosomes to each child. Therefore, a woman with an X-linked dominant disorder has a 50 percent chance of having an affected daughter or son with each pregnancy.

• X-linked recessive inheritance: Because of the difference in sex chromosomes, the probability of passing on an X-linked recessive disorder also differs between men and women. The sons of a man with an X-linked recessive disorder will not be affected, and his daughters will carry one copy of the altered gene. With each pregnancy, a woman who carries an altered gene for X-linked recessive has a 50 percent chance of having sons who are affected and a 50 percent chance of having daughters who carry one copy of the altered gene. Females with one gene variant associated with an X-linked recessive disorder typically have no or very mild signs or symptoms of the condition.

• X-linked: Because the inheritance pattern of many X-linked disorders is not clearly dominant or recessive, some experts suggest that conditions be considered X-linked rather than X-linked dominant or X-linked recessive. As above, the probability of passing on an X-linked disorder differs between men and women. The sons of a man with an X-linked disorder will not be affected, but all of his daughters will inherit the altered gene and may develop signs and symptoms of the condition. A woman passes on one or the other of her X chromosomes to each child. Therefore, with each pregnancy, a woman with an X-linked disorder has a 50 percent chance of having a child with the altered gene. An affected daughter may have milder signs and symptoms than an affected son.

• Y-linked inheritance: Because only males have a Y chromosome, only males can be affected by and pass on Y-linked disorders. All sons of a man with a Y-linked disorder will inherit the condition from their father.

• Codominant inheritance: In codominant inheritance, each parent contributes a different version of a particular gene, and both versions influence the resulting genetic trait. The chance of developing a genetic condition with codominant inheritance, and the characteristic features of that condition, depend on which versions of the gene are passed from parents to their child.

• Mitochondrial inheritance: Mitochondria, which are the energy-producing centers inside cells, each contain a small amount of DNA. Disorders with mitochondrial inheritance result from variants in mitochondrial DNA. Although these disorders can affect both males and females, only females can pass variants in mitochondrial DNA to their children. A woman with a disorder caused by changes in mitochondrial DNA will pass the variants to all of her daughters and sons, but the children of a man with such a disorder will not inherit the variant.

It is important to note that the chance of passing on a genetic condition applies equally to each pregnancy. For example, if a couple has a child with an autosomal recessive disorder, the chance of having another child with the disorder is still 25 percent (or 1 in 4). Having one child with a disorder does not “protect” future children from inheriting the condition. Conversely, having a child without the condition does not mean that future children will definitely be affected.

Although the chances of inheriting a genetic condition appear straightforward, factors such as a person's family history and the results of genetic testing can sometimes modify those chances. In addition, some people with a disease-causing mutation never develop any health problems or may experience only mild symptoms of the disorder. If a disease that runs in a family does not have a clear-cut inheritance pattern, predicting the likelihood that a person will develop the condition can be particularly difficult.

Estimating the chance of developing or passing on a genetic disorder can be complex. Genetics professionals can help people understand these chances and help them make informed decisions about their health.

Cascade testing for BRCA1, BRCA2, and other genetic changes that cause hereditary breast and ovarian cancer can find family members who are more likely to get breast, ovarian, and other cancers. They can take steps to prevent these cancers or find them early, when treatments are more likely to be successful.

If you have been diagnosed with a BRCA1,BRCA2, or another genetic change that makes you more likely to get breast, ovarian, and other cancers, your family members could have the same genetic change. Family members who decide to get tested should be checked for the same genetic change that you have. Getting screened using a cancer test available for a variety of cancers might not include the genetic change that you have, so family members should talk to their doctors about making sure that their test includes your genetic change.

Ask your genetic counselor or other health care provider if the company that did your genetic testing offers free or discounted genetic testing to your at-risk family members. In some cases, free or discounted testing is only available for a limited amount of time after your initial test.

Genetic testing for BRCA1, BRCA2, and other genetic changes is currently recommended for some women with breast cancer, men with breast cancer, and women with ovarian, peritoneal, or fallopian tube cancer. However, most people who get breast cancer do not have a BRCA1, BRCA2, or other genetic change that causes hereditary cancer, so having a family member with cancer does not always mean that cascade testing is needed. A genetic counselor can help you decide if genetic testing is recommended.

What Are My Family Members’ Chances of Having the Same Genetic Change?

• If you have a BRCA1 or BRCA2 genetic change, your mother, father, children, and siblings have a 1 in 2 (50%) chance of having the same genetic change.
• Your half-siblings, aunts, uncles, grandmothers, and grandfathers have a 1 in 4 (25%) chance of having the same genetic change.
• Your cousins and other more distantly related family members can have as much as a 1 in 8 (12.5%) chance of having the same genetic change.

A health care provider, such as a genetic counselor, can help with personalized risk estimates for each person in your family.

Who Should Get Tested?

When possible, genetic testing should start with family members who are most closely related to the person who has the BRCA1, BRCA2, or other genetic change. However, if a family member is not available for testing (for example, if the family member does not want to be tested or has died), then testing can start with more distant family members.

Because interventions for BRCA1, BRCA2, and most other genetic changes that cause hereditary breast and ovarian cancer start in adulthood, most current guidelines recommend that testing for these genetic changes should only be done on adults (18 years of age and older). This allows children, rather than their parents, to make their own decision about genetic testing once they become adults. However, if the genetic change increases the chances of getting cancer in childhood, then genetic testing of children in the family would be appropriate. Talk to your genetic counselor or other health care provider about how to provide information to your children so they are empowered to make their own decisions about genetic testing when the time is right.

How do family members get tested?

The genetic counselor or health care provider who diagnosed you might be able to help schedule genetic counseling and testing for your family members. Provide your genetic test report to any genetic counselor or health care provider who orders testing for your family. If free or discounted cascade testing for family members is limited to a certain amount of time from the first genetic test report, they might need a copy of your report to show the date of your test. Some insurance companies will cover genetic testing for families if a known genetic change is found. A genetic counselor or health care provider can give more information on your specific insurance coverage.

Although more than one million people in the U.S. have familial hypercholesterolemia, only about 30% know they have it. Finding people with FH early is important to help prevent coronary heart disease. If you have FH, your cholesterol levels are high starting at birth, unlike people who develop high cholesterol later due to behaviors such as smoking or an unhealthy diet. This means that heart disease starts to develop earlier, making you more likely to have a heart attack at a younger age. The sooner a person with FH is identified, the quicker they can start taking medicine to lower their LDL cholesterol levels and reduce their risk of getting heart disease in the future.

If you have been diagnosed with FH, your parents, sisters, brothers, and children are at higher risk of having it too. Since FH is an inherited disorder, testing family members is an effective way of finding more cases of FH. The good news is they can be tested for FH through genetic testing, a blood cholesterol test, or both. This method of tracing FH through family members is called cascade testing.

What Are My Family Members’ Chances of Having FH?

If you have FH, the chance that your family member has FH depends on what kind of genetic change is found in your family and how closely related you are to your family member. If your genetic test results show that you have a known genetic change, family members who get genetic testing should be checked for the same genetic change. For every new person identified with FH, this process of testing family members is repeated.

FH can be caused by different genetic changes:

• FH is most often caused by genetic changes in the LDLR, APOB, or PCSK9 genes, and less commonly the STAP1 or APOE genes. If you have a genetic change in one of these genes, you have heterozygous FH, the most common form of FH:
  • Your mother, father, children, and siblings have a 1 in 2 (50%) chance of having FH.
  • Your half-siblings, aunts, uncles, grandmother, and grandfather have a 1 in 4 (25%) chance of having FH.
  • Your cousins and other more distantly related family members have a 1 in 8 (12.5%) or smaller chance of having FH.

• Homozygous FH is a rare, more severe form of FH and is caused by having genetic changes in both copies of the APOB, LDLR, or PCSK9 genes. If you have homozygous FH:
  • Your parents and children have heterozygous FH.
  • Your siblings have a 1 in 2 (50%) chance of having heterozygous FH and a 1 in 4 (25%) chance of having homozygous FH.
  • Your half-siblings, aunts, uncles, grandmother, and grandfather have a 1 in 2 (50%) chance of having heterozygous FH.
  • Your cousins and other more distantly related family members have a 1 in 4 (25%) or smaller chance of having heterozygous FH.

• Genetic changes in both copies of the LDLRAP1, LIPA, ABCG5/ABCG8, or PNPLA5 genes can cause FH-like conditions which are similar to homozygous FH. If you have one of these FH-like conditions due to genetic changes in both copies of one of these genes:
  • Family members such as your parents, children, and more distant relatives can have one copy of the genetic change but will not have the FH-like condition (unless they inherit a genetic change in the other copy of the gene).
  • Your siblings have a 1 in 4 (25%) chance of having the FH-like condition.
  • Family members with one copy of the genetic change could have a child with the FH-like condition if the other parent also has a genetic change in one (or both) copies of the same gene.

A health care provider such as a genetic counselor can help with personalized risk estimates for each person in your family. In addition to the genetic changes listed above, researchers have found other rare genetic changes that are specific to families. Genetic testing might find one of these genetic changes in your family.

For some people with FH, genetic testing will not find a genetic change in any of the genes known to cause FH. This is because not all genetic changes that cause FH are known. Their family members may still be at increased risk for FH. In other people, many genetic changes together cause FH. In these cases, family members usually will not be at increased risk for FH.

Who Should Get Tested?

Early diagnosis of FH can prevent heart attacks and death. Because people with FH have high LDL-cholesterol starting from birth, genetic testing is recommended for family members of all ages. Genetic testing is the preferred method for diagnosis. Another option is blood work to check LDL cholesterol levels. This can be done even when the genetic cause of FH is unknown.

It is usually best to start testing family members who are most closely related to the person who was diagnosed with FH, such as their mother, father, siblings, and children. However, if a family member is not available for testing (for example, if a family member does not want to be tested or has died), then moving to more distant family members is also appropriate.

How Do Family Members Get Genetic Testing?

The genetic counselor or health care provider who diagnosed you might be able to help schedule genetic counseling and testing for your family members. Provide your genetic test report to any genetic counselor or health care provider who orders testing for your family. If free or discounted cascade testing for family members is limited to a certain amount of time from the first genetic test report, they might need a copy of your report to show the date of your test. Some insurance companies will cover genetic testing for families if a known genetic change is found. A genetic counselor or health care provider can give more information on coverage with your specific insurance.

Cascade testing for Lynch syndrome can find family members who are more likely to get colorectal (colon), uterine (endometrial), ovarian, and other cancers. Knowing about their increased risk allows family members to take steps to prevent these cancers or find them early when treatments are more likely to be successful.

If you have been diagnosed with Lynch syndrome, your family members could also have it. Family members who decide to get genetic testing for Lynch syndrome should be checked for the same genetic change you have. Getting screened using a cancer test available for a variety of cancers might not include the genetic change that you have, so family members should talk to their doctors about making sure that their test includes your genetic change.

Ask your genetic counselor or other health care provider if the company that did your genetic testing offers free or discounted genetic testing to your at-risk family members. In some cases, free or discounted testing is only available for a limited amount of time after your initial test.

Current recommendations state that colorectal (colon) and some uterine (endometrial) tumors should be tested for Lynch syndrome. However, most people who get colorectal (colon) or uterine (endometrial) cancer do not have Lynch syndrome, so having a family member with these cancers does not necessarily mean that cascade testing is needed. A genetic counselor can help you decide if genetic testing is recommended.

What Are My Family Members’ Chances of Having Lynch Syndrome?

• Your mother, father, children, and siblings have a 1 in 2 (50%) chance of having Lynch syndrome.
• Your half-siblings, aunts, uncles, grandmothers, and grandfathers have a 1 in 4 (25%) chance of having Lynch syndrome.
• Your cousins and other more distantly related family members can have as much as a 1 in 8 (12.5%) chance of Lynch syndrome.

A health care provider, such as a genetic counselor, can help with personalized risk estimates for each person in your family.

Who Should Get Tested?

When possible, genetic testing should start with family members who are most closely related to the person diagnosed with Lynch syndrome. However, if a family member is not available for testing (for example, the family member does not want to be tested or has died), testing can start with more distant family members.

Because interventions for Lynch syndrome start in adulthood, most current guidelines recommend that testing for Lynch syndrome should only be done on adults (18 years of age and older). This allows children, rather than their parents, to make their own decision about genetic testing once they become adults. Talk to your genetic counselor or other health care provider about how to provide information to your children so they are empowered to make their own decision about genetic testing when the time is right.

How Do Family Members Get Tested?

The genetic counselor or health care provider who diagnosed you might be able to help schedule genetic counseling and testing for your family members. Provide your genetic test report to any genetic counselor or health care provider who orders testing for your family. If free or discounted cascade testing for family members is limited to a certain amount of time from the first genetic test report, they might need a copy of your report to show the date of your test. Some insurance companies will cover genetic testing for families if a known genetic change is found. A genetic counselor or health care provider can give more information on coverage with your specific insurance.

The results of genetic tests are not always straightforward, which often makes them challenging to interpret and explain. Therefore, it is important for patients and their families to ask questions about the potential meaning of genetic test results both before and after the test is performed. When interpreting test results, health care providers consider a person’s medical history, family history, and the type of genetic test that was done.

A positive test result means that the laboratory found a change in a particular gene, chromosome, or protein of interest. Depending on the purpose of the test, this result may confirm a diagnosis, indicate that a person is a carrier of a particular genetic variant, identify an increased risk of developing a disease (such as cancer), or suggest a need for further testing. Because family members have some genetic material in common, a positive test result may also have implications for certain blood relatives of the person undergoing testing. It is important to note that a positive result of a predictive or presymptomatic genetic test usually cannot establish the exact risk of developing a disorder. Also, health care providers typically cannot use a positive test result to predict the course or severity of a condition. Rarely, tests results can be false positive, which occur when results indicate an increased risk for a genetic condition when the person is unaffected.

A negative test result means that the laboratory did not find a change that is known to affect health or development in the gene, chromosome, or protein under consideration. This result can indicate that a person is not affected by a particular disorder, is not a carrier of a specific genetic variant, or does not have an increased risk of developing a certain disease. It is possible, however, that the test missed a disease-causing genetic alteration because many tests cannot detect all genetic changes that can cause a particular disorder. Further testing, or re-testing at a later date, may be required to confirm a negative result. Rarely, tests results can be false negative, which occur when the results indicate a decreased risk or a genetic condition when the person is actually affected.

In some cases, a test result might not give any useful information. This type of result is called uninformative, indeterminate, inconclusive, or ambiguous. Uninformative test results sometimes occur because everyone has common, natural variations in their DNA, called polymorphisms, that do not affect health. If a genetic test finds a change in DNA that has not been confirmed to play a role in the development of disease, known as a variant of uncertain significance (VUS or VOUS), it can be difficult to tell whether it is a natural polymorphism or a disease-causing variant. For these variants, there may not be enough scientific research to confirm or refute a disease association or the research may be conflicting. An uninformative result cannot confirm or rule out a specific diagnosis, and it cannot indicate whether a person has an increased risk of developing a disorder. In some cases, testing other affected and unaffected family members can help clarify this type of result.

Secondary findings are genetic test results that provide information about changes (variants) in a gene unrelated to the primary purpose for the testing.

When a clinician orders a genetic test to discover the genetic cause of a particular condition, the test will often sequence one or a few genes that seem most likely to be associated with that individual’s set of signs and symptoms. However, if the individual’s signs and symptoms do not have an obvious genetic cause, a clinician might order a test that sequences all of the pieces of an individual's DNA that provide instructions for making proteins (called an exome) or a test that sequences all of an individual’s DNA building blocks (nucleotides), called a genome. These tests are called whole exome sequencing and whole genome sequencing, respectively.

Many more genetic changes can be identified with whole exome and whole genome sequencing than by sequencing just one or a few genes. Sometimes, testing finds a variant that is associated with a condition other than the one for which testing was originally indicated. This is called a secondary finding. Some individuals with a secondary finding may not yet have any of the symptoms associated with the condition, but may be at risk of developing it later in life. For example, a person with a variant in the BRCA1 gene, which is associated with an increased risk of breast and ovarian cancer, may not have developed cancer. Other individuals with secondary findings may have a known medical condition, such as extremely high cholesterol, but receive results that indicate a genetic cause for that condition, such as a variant in the LDLR gene.

In 2013, then again in 2017 and 2021, the American College of Medical Genetics and Genomics (ACMG) recommended that all labs performing whole exome and whole genome sequencing tests report particular secondary findings, in addition to any variants that are found related to the primary purpose of the testing. In the 2021 updated recommendations, ACMG proposed a list of 73 genes that are associated with a variety of conditions, from cancer to heart disease. The 73 genes for which secondary findings are reported were chosen because they are associated with conditions that have a definable set of clinical features, the possibility of early diagnosis, a reliable clinical genetic test, and effective intervention or treatment. The goal of reporting these secondary findings to an individual is to provide medical benefit by preventing or better managing health conditions. The variants that are reported are known to cause disease. Variants of unknown significance, whose involvement in disease at the current time is unclear, are not reported.

The information provided by secondary findings can be very important because it may help prevent a disease from occurring or guide the management of signs and symptoms if the disease develops or is already present. However, as with any type of medical diagnosis, the news of an unexpected potential health problem may lead to additional health costs and stress for individuals and their families. On the basis of secondary findings, additional testing to confirm results, ongoing screening tests, or preventive care may be advised. Individuals receiving whole exome or whole genome sequencing can choose to “opt out” of analysis of the 73 secondary finding genes and not receive variant results. As whole exome and whole genome sequencing become more common, it is important for individuals to understand what type of information they may learn and how it can impact their medical care.

What is Genetic Counseling?

Genetic counseling gives you information about how genetic conditions might affect you or your family. The genetic counselor or other healthcare professional will collect your personal and family health history. They can use this information to determine how likely it is that you or your family member has a genetic condition. Based on this information, the genetic counselor can help you decide whether a genetic test might be right for you or your relative.

Reasons for Genetic Counseling

Based on your personal and family health history, your doctor can refer you for genetic counseling. There are different stages in your life when you might be referred for genetic counseling:

• Planning for Pregnancy: Genetic counseling before you become pregnant can address concerns about factors that might affect your baby during infancy or childhood or your ability to become pregnant, including
  • Genetic conditions that run in your family or your partner’s family
  • History of infertility, multiple miscarriages, or stillbirth
  • Previous pregnancy or child affected by a birth defect or genetic condition
  • Assisted Reproductive Technology (ART) options
• During Pregnancy: Genetic counseling while you are pregnant can address certain tests that may be done during your pregnancy, any detected problems, or conditions that might affect your baby during infancy or childhood, including
  • History of infertility, multiple miscarriages, or stillbirth
  • Previous pregnancy or child affected by a birth defect or genetic condition
  • Abnormal test results, such as a blood test, ultrasound, Chorionic Villus Sampling (CVS), or amniocentesis
  • Maternal infections, such as Cytomegalovirus (CMV), and other exposures such as medicines, drugs, chemicals, and x-rays
  • Genetic screening that is recommended for all pregnant women, which includes cystic fibrosisexternal icon, sickle cell disease, and any conditions that run in your family or your partner’s family

• Caring for Children: Genetic counseling can address concerns if your child is showing signs and symptoms of a disorder that might be genetic, including
  • Abnormal newborn screening results
  • Birth defects
  • Intellectual disability or developmental disabilities
  • Autism spectrum disorders (ASD)
  • Vision or hearing problems

• Managing Your Health: Genetic counseling for adults includes specialty areas such as cardiovascular, psychiatric, and cancer. Genetic counseling can be helpful if you have symptoms of a condition or have a family history of a condition that makes you more likely to be affected with that condition, including
  • Hereditary breast and ovarian cancer (HBOC) syndrome
  • Lynch syndrome (hereditary colorectal and other cancers)
  • Familial hypercholesterolemia
  • Muscular dystrophy and other muscle diseases
  • Inherited movement disorders such as Huntington’s disease
  • Inherited blood disorders such as sickle cell disease

Following your genetic counseling session, you might decide to have genetic testing. Genetic counseling after testing can help you better understand your test results and treatment options, help you deal with emotional concerns, and refer you to other healthcare providers and advocacy and support groups.