'People think if we do a genetic test, we can look for everything and if it comes back as a normal test, then everything will be healthy', says Jill Fischer, director of the genetic counselling programme at Kean University in New Jersey, summarising one of the fundamental misconceptions about genetic counselling today. In fact, a clear or negative test does not guarantee a healthy child.
Throughout the American Society for Reproductive Medicine (ASRM) Today - 'Misconceptions about genetic counselling' podcast, Fischer answered questions from host Jeffery Hayes to explore some of these common misunderstandings - illuminating the complexity of the role a genetic counsellor plays in assisted reproductive medicine.
First Fischer clarifies the role of the genetic counsellor. According to her, these are 'in house genetics experts, decision-makers sitting at the table deciding policy and fostering patient-centred care'. Although in some clinics the genetic's role is associated with the preimplantation genetic testing team, there is a growing awareness among assisted reproductive medical teams of the benefits genetic counsellors can bring. Fischer explained that close interaction with patients can help mitigate clinics' risk for liability through understanding genetic testing and consent, alongside written counselling reports. Genetic counsellors also assist with the initiation of treatment and oversee the patient journey for specific areas of male and female infertility, carrier screening and donor gamete programmes. They offer valuable advice regarding non-invasive or other prenatal screening/testing as patients transition out of the clinic and provide psychosocial support.
The short but informative interview summarised the most important genetic misconceptions among reproductive practitioners. It is commonly believed that both partners in a couple need to have the same genetic mutation to be at risk. However, if this was the case, then couples on treatment with different mutations in the same gene would not be identified to be at risk. Furthermore, different autosomal recessive diseases have varying numbers of mutations: sickle cell anaemia is only caused by one mutation, a person either has it or they do not. For cystic fibrosis, there are over 2000 different associated mutations. Some mutations can stop a gene from working or can modify a protein a gene makes, affecting its functionality. Mutations are often described as severe, moderate or mild, the severity of the disease can depend on the type of mutation present.
The second misconception is that only people of a certain ethnicity get certain diseases. Fischer deconstructed the misunderstanding that although a genetic disorder may be more common in a particular population, it does not mean that it is non-existent in other populations. Fischer gave the example of Tay Sachs diseases which was thought to solely occur in the Ashkenazi Jewish population, but it has also been found at similar frequencies in other geographical populations. An interesting topic that arose from was the concept of heterozygote advantage – a selective advantage to being a carrier of an autosomal recessive condition in certain situations. A carrier is healthy, and they do not have symptoms of the disorder because it takes two mutations to cause the disease. Examples include sickle cell anaemia where a carrier is protected against malaria, and cystic fibrosis where a carrier was protected against cholera. As carrier individuals are more likely to survive these diseases, the mutations perpetuate in the population as carriers have children. Again, although both of these advantages are associated with certain populations, it does not mean they do not exist in other populations.
The key take-home message was that a clear or negative genetic test does not guarantee a healthy child, instead, it can greatly reduce, but does not eliminate risk. It is clear from the podcast that access to a genetic counsellor is highly valuable for clinics; however, the model to add this to existing services is not clear. Fischer explained that service delivery of effective genetic counselling has progressed from the traditional face-to-face appointment to phone or video, so that clinics can outsource or contract independent genetic counselling services that specialise in assisted reproduction and infertility.
The podcast does more than just demystify the role of a genetic counsellor. By delving into some common misconceptions surrounding genetics, the succinct and informative podcast addresses the importance of on-boarding specialist genetic support for assisted reproductive medical providers.