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What is genetic counselling?

What is genetic counselling?

25/05/2019
Posted by:

J.Phillips


Genetic counselling, a unique healthcare service

If you or someone in your family has been diagnosed with a genetic disease then chances are you’ve already heard of genetic counselling, but many people have not. I have come to know this quite well since I hope to one day become a genetic counsellor. In my experience, whenever someone asks about my career goals it is almost invariably followed up with the question, “what is genetic counselling?”. I have given my little speech about it so many times now I could probably recite it in my sleep! But in all honesty, no canned response in a passing conversation would be able to do it justice. So, what is genetic counselling?

Genetic counselling is a very unique service provided in the healthcare industry. In a system that is focused on diagnosing and treating as many patients as possible, many doctors simply don’t have the time to sit down with their patients and help them understand all of the components of genetic disease and how to adapt to the changes in life that disease brings. This is where genetic counselling comes in. Being confronted with a genetic disorder can be a very overwhelming experience, and if you’ve found yourself in that position it is likely that you will have many questions. What is this disease? (There are over 7000 rare diseases, affecting more that 350 million people worldwide). What testing options are there? What treatment options are there? What does this mean for my family? What does this mean for my children? How am I supposed to handle all of this new information? How does one cope with this change? Or potentially even grieve? I could go on, but I’m sure you get the point.

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Genetic counselling goes beyond just diagnosing genetic diseases. Genetic counsellors are health professionals who have received specialty training in both medical genetics and counselling; this background is the reason genetic counsellors provide care that is truly unique in the healthcare industry. Their education in medical genetics allows them to gather your personal and family health history together in order to help determine the likelihood of genetic disease occurring in your child, future children, family members, or yourself. But not only do they have an understanding of medical genetics, their expertise is also coupled with extensive experience educating patients who aren’t already familiar with biology or genetics.

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Educating patients and families about the particular genetic disorder they are confronted with is one of the main components of a genetic counselling session. The manifestation of genetic disorders is often complicated. Concepts like variable expressivity and reduced penetrance can be very confusing in cases where family members experience different symptoms and patterns of inheritance are not straightforward. Thankfully, genetic counsellors are able to help patients appreciate complex genetic information and also respond to any questions they may have about the disorder they are faced with. After a visit with a genetic counsellor, patients should expect to have an understanding of:

  • The medical facts surrounding the disorder including its features, probable course, and range of variability
  • The genetic basis of the disorder and any environmental factors that may influence its onset
  • Their personal genetic risk as well as the recurrence risk for their family members
  • The diagnostic process and any genetic tests for the disorder, if available
  • The psychological, social, and economic impacts of the disease, both positive and negative
  • Management and/or treatment options including clinical trials, if available
  • If desired, reproductive strategies to ameliorate or prevent recurrence of the disorder
  • Any available resources, such as advocacy or support groups

The counselling element of their education is what allows genetic counsellors to provide support throughout the appointment, so that their patients are able to cope with the emotional responses that accompany genetic disease. These emotional responses can get in the way of patients assimilating the often overwhelming amount of information presented to them, and therefore these responses must be anticipated and addressed. This is especially important, since patient understanding throughout the session is necessary for patients to be able to make informed decisions about their healthcare.

Patient autonomy is a value central to genetic counselling sessions. Genetic counsellors help patients make informed decisions that are in line with their own needs and personal beliefs using an interactive and non-directive approach. To ensure this, genetic counselling appointments typically will involve discussion of the patient’s:

  • Experiences with and prior conceptions about genetic disease
  • Personal and family goals
  • Religious and/or cultural beliefs and values
  • Family and interpersonal dynamics
  • Social supports and coping styles

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Genetic counsellors may specialize in a particular area, such as prenatal or cancer genetics, or they may provide general care to any person, couple, or family whose lives have been impacted by genetic disease. Depending on the context and reasoning for being referred, genetic counselling appointments can broadly be categorized into three different types: prenatal, pediatric, and general (adult) genetic counselling. For instance, a couple who already has a child with Tay-Sachs disease, a condition that progressively destroys brain and spinal cord nerve cells, may opt to see a prenatal genetic counsellor if they are thinking about having another child. A pediatric genetic counsellor on the other hand, might see a family whose baby has been diagnosed through newborn screening with a rare metabolic condition called phenylketonuria, which can lead to serious health problems including intellectual disability if left untreated. Lastly, an individual with a family history of breast cancer may be referred to a general (or cancer) genetic counsellor if she is concerned about her own risk for developing breast cancer. The rest of this article explores these three fields of genetic counselling in more detail.

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Prenatal Genetic Counselling

Prenatal genetic counselling is for women and couples that are pregnant, or planning to become pregnant, and are concerned about how genetics may impact their pregnancy, child, or ability to get pregnant. Any of the following reasons may warrant a referral to a prenatal genetic counsellor:

  • Personal and/or family history of a genetic disorder, birth defect, or chromosomal disorder. This can include history of intellectual disabilities, developmental disabilities, and other known or unknown medical conditions
  • Planning to become pregnant again after having a previous child affected by any of the above
  • A couple who is having difficulties becoming pregnant

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A prenatal genetic counsellor will address these concerns and help patients better appreciate risks related to their pregnancy. Many genetic disorders are passed through generations in complex inheritance patterns; however, there are also many non-genetic or environmental factors that can influence recurrence risk. Understanding risk is certainly not intuitive. Often women and couples are faced with critical decisions that depend on their understanding of these risks; the role of a prenatal genetic counsellor here is to help them make informed decisions that are in line with personal goals and values. A person who is at increased risk of having their pregnancy affected by a heritable disorder can expect a prenatal genetic counsellor to educate them more about that particular disorder. This education includes what to expect when raising a child with special needs and how to prepare for the birth of that child.

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Additionally, a prenatal genetic counselling session will involve a discussion about options for how to manage risk, how these options align with personal needs and values, and how to anticipate and cope with the emotional reactions that come along with making difficult reproductive decisions. There are screening options (such as fetal ultrasound or blood tests) , that can detect an increased risk of certain disorders or birth defects, as well as invasive testing options (such as chorionic villus sampling or amniocentesis) , that are able to diagnose certain conditions during pregnancy. For couples who wish to ameliorate risk in a future pregnancy, there are assisted reproduction techniques that can help, such as preimplantation genetic diagnosis or sperm and egg donation. Pregnancy termination and adoption are also options that can be discussed in an appointment with a prenatal genetic counsellor.

Since genetic counselling follows the principles of being non-directive and interactive, the outcome of each session will vary depending the needs, values, and beliefs of the patient. This is the case for all genetic counselling appointments, but especially for prenatal genetic counselling where strongly-held moral or religious beliefs may play a large role in reproductive decisions. The risk management options discussed here are not free of their own risks however, and these risks will also be discussed in the visit. By the end of an appointment with a prenatal genetic counsellor, patients should feel confident about making reproductive decisions based on a complete understanding of their risks, options, needs, and values.

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Pediatric Genetic Counselling

Pediatric genetic counselling is for children with known or suspected genetic conditions, as well as their families. A doctor might refer a family to a pediatric genetic counsellor if their child:

  • Has been diagnosed with a genetic disease through newborn screening
  • Is experiencing signs or symptoms of a disorder with a genetic component, including birth defects, vision or hearing problems, intellectual disabilities, and developmental delays
  • Has developed new symptoms that suggest a particular genetic disorder

The role of pediatric genetic counsellors is to help diagnose and provide support for children and their families whose lives have been affected by heritable disorders. These disorders can often appear without warning. All babies born in Alberta undergo newborn screening, and for the most part, this is common practice around the world to varying degrees. Newborn screening tests for rare inherited disorders including methylmalonic acidemia, and citrullinemia, both of which can be life-threatening. After the birth of a baby with a genetic disorder or birth defect, pediatric genetic counsellors can help families make sense of why this may have happened, and help them grieve the loss of the “normal” or “healthy” baby they had hoped for. Pediatric genetic counsellors can also support families who are grieving the stillbirth of a baby with an abnormality, or the death of an infant with a genetic condition. Genetic diseases and congenital anomalies are the leading cause of death in the Neonatal Intensive Care Unit.

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Other times, genetic conditions don’t become apparent until later on in the development of the child, as is the case with Angelman syndrome, a nervous system disorder that typically does not appear till 6 to 12 months of age. If a child has started showing symptoms of a potential genetic disorder, a pediatric genetic counsellor can help by gathering the information needed to establish a diagnosis. Often inherited disorders have common initial symptoms like delayed development, intellectual disability, and heart defects; determining a diagnosis requires expertise in genetic disease and clinical features. Some genetic disorders are very rare and not well researched; in these cases, a diagnosis must be made based upon clinical features alone.

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If the genetic basis of the suspected disorder is known, however, then there may be a test available to diagnose it. In these cases, a pediatric genetic counsellor will discuss with families the limits of the test and the possible results. They also help families anticipate the emotional impact of either positive or negative test results and address any fears or concerns. By the end of a visit with a pediatric genetic counsellor, patients and/or their families should feel comfortable in their understanding of the particular genetic condition they are faced with, the impacts it will have, and the medical services, social services, and support groups that are available to them as they adjust to life with a genetic disease.

 

General Genetic Counselling

General genetic counselling is for adults who are affected by, or at risk for, a genetic disorder. A doctor might refer someone to a general genetic counsellor or a specialized genetic counsellor if they:

  • Have a family history of a genetic disorder, such as Huntington disease or cystic fibrosis
  • Have a family history of a disease with a genetic component, such as hereditary cancer, cardiovascular disease, or dementia
  • Have a family history of early death, from known or unknown medical conditions
  • Are showing symptoms of a genetic condition, with or without family history

Adults who are concerned about their personal risk for developing a genetic condition may seek genetic counselling from a specialized genetic counsellor or a general genetics clinic. Cardiovascular, psychiatric, and cancer genetics are common specialties for genetic counsellors due to the relatively high frequencies of these types of conditions. However, many other genetic diseases, such as Gaucher disease, which affects multiple tissues and organs, are much rarer and patients would instead be referred to a genetic counsellor at a general genetics clinic.

Some particular types of cancers tend to run in families. For example, hereditary breast cancer, and ovarian cancer, are caused by mutations in the BRCA1 and BRCA2 genes. Someone who has had multiple family members affected by these cancers may want to talk to a genetic counsellor about getting tested for these mutations. Although genetic testing is not available for all types of hereditary cancer, there are many potential benefits to getting these tests when they are available. Knowing that they are at higher risk for developing cancer can help people make positive lifestyle choices to manage that risk, such as adopting a healthier diet, a new exercise regimen, or getting early screening to try and catch cancer at its beginning stages of development. In some cases where a person already has cancer, genetic testing can help guide decisions about the course of treatment. There are many hereditary cardiovascular diseases (hypertrophic cardiomyopathy, Andersen-Tawil Syndrome, and Marfan syndrome, to name a few), that can be tested for as well. In the case of cardiovascular disease, testing can serve to confirm a diagnosis, guide treatment, identify family members at risk, and sometimes explain cases of sudden death.

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When psychiatric conditions like autism spectrum disorder, depression, or Alzheimer disease, run in families, a genetic counsellor can help patients understand the cause and the chances of it recurring in their family. For those pregnant or planning on becoming pregnant, a genetic counsellor can discuss the risk of passing a psychiatric disorder on to their child, and if they are taking any medications to treat a psychiatric illness, a genetic counsellor can work collaboratively with patients and their mental health professionals to ensure safety for both the mother and the baby during pregnancy. However, genetic testing is typically not offered for heritable psychiatric conditions as they are diseases of complex etiology with no easy genetic diagnosis.

Once a genetic condition has been identified in a family, family members of the initial patient may want to be referred for genetic counselling and genetic testing to determine their personal risk. For adult onset conditions like Huntington disease, or familial amyotrophic lateral sclerosis (familial ALS), pre-symptomatic testing can remove uncertainty, reduce anxiety, and help patients make important medical and life decisions. When a recessive genetic disorder is diagnosed in a family, other members of that family may wish to get testing to find out their carrier status, especially if they or their partner are of an ethnic background where that disorder occurs in higher frequency and they are planning on having children.

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Although many potential benefits for genetic testing have been discussed here, there are also many reasons why someone would choose NOT to get genetic testing done. For some, ignorance is bliss; a positive pre-symptomatic test for Huntington disease has the potential to cause unnecessary stress and anxiety with every normal clumsy behaviour, while a negative test could come with unexpected emotions like guilt that could interfere with family dynamics. Also, as is the case for Huntington disease, sometimes there are no known treatments available to prevent or delay the onset of the condition.

In cases where genetic disease has been present in the family for generations, a negative test might contradict long-held beliefs about a person’s risk for developing or passing on a genetic disease to their children. This can be quite disorienting for some. But even if you personally believe 100% that you would want to know your status, the nature of genetic diseases means that your test result (positive or negative) could inform the status of a family member who would prefer to remain in “blissful” ignorance. Clearly the decision to get testing done is more complicated than it might seem. But when faced with these decisions, genetic counsellors are there to help patients consider all of these factors and make the choice that is right for them and their family.

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Understanding what genetic counselling is or what genetic counsellors do for patients is as complicated as understanding genetic disease itself. There is no one type of genetic disease that affects families, and as such there is not one type of service that is provided by genetic counsellors. It is possible, and very likely, that in the future the role of genetic counsellors will expand as we learn more about our genome. As more genetic variations are discovered that enhance our understanding of personalized medicine, genetic counsellors may soon see themselves counselling patients about therapeutic drugs or managing their susceptibilities to environmental pollutants. Perhaps the best way to describe genetic counselling after all is simply to say that it is a non-directive communication process that empowers patients to make informed decisions about their healthcare.

 

This article has been produced by Jenna Phillips, B.Sc. and edited by Kerri Bryant. Reproduction and reuse of any portion of this content requires Merogenomics Inc. permission and source acknowledgment. It is your responsibility to obtain additional permissions from the third party owners that might be cited by Merogenomics Inc. Merogenomics Inc. disclaims any responsibility for any use you make of content owned by third parties without their permission.

 

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