Watching a loved one suffer from a debilitating disease is heartbreaking. It’s also scary thinking about whether you may also develop the same condition or pass it on to your own children.
Preimplantation genetic testing (PGT) is an option for many people facing the prospect of passing on a heritable adult-onset disorder. It’s a difficult decision, and you’ll likely have many questions about the process and factors to consider before embarking on this journey.
What are adult-onset disorders?
Sometimes people inherit a genetic mutation or malfunction. In the case of an adult-onset disorder, this mutation may go unnoticed for decades, until it manifests as a disease. Certain genes create an environment within the body where a particular disease might develop easier, but, unlike childhood diseases, these take many years of interactions within the body and from the environment for the disease to develop.
Disorders that develop later in life from an inherited mutation may be caused by a single gene or by multiple genes combined with environmental factors. Some single-gene disorders, such as Huntington Disease, eventually lead to disease regardless of environmental factors. Breakthroughs in science allow us an ever-increasing ability to test for single-gene mutations and even prevent them from being passed on to future generations. Inherited cancer syndromes and hypertrophic cardiomyopathy are examples of adult-onset disorders with a genetic cause that can be pinpointed through genetic testing.
What adult-onset disorders can be diagnosed?
PGT is most commonly used for conditions in which there is a single, known gene that causes the disease.
Other conditions that you may consider undergoing PGT for include:
- Some forms of cancer (hereditary breast and ovarian cancer syndrome, Lynch syndrome, diffuse gastric cancer)
- Certain heart disease (dilated cardiomyopathy, arrhythmias)
- Polycystic kidney disease
- Gerstmann-Sträussler-Scheinker (GSS) syndrome
- Frontotemporal dementia
This list is far from comprehensive, and more conditions can be found here. To undergo PGT, however, the disease-causing mutation in the gene associated with the disease must be identified.
What are some considerations?
The process. In vitro fertilization (IVF) with PGT is a medical process that requires several doctor’s appointments, tests, medications, and minor surgical procedures. Some patients feel these steps are well worth it to achieve the desired outcome, but some aspects of the process can be mentally or physically challenging. Hormone treatments to stimulate ovulation can lead to mood swings or emotional periods that resolve when the treatments end. It’s also possible that the first cycle of IVF may not lead to a successful pregnancy.
The future. PGT for an adult-onset disorder requires an immediate financial investment for a long-term benefit. Most couples weigh the possibility of whether a cure could be developed in the coming decades. The American Society for Reproductive Medicine, an organization involved in developing legislation related to reproductive rights, issued an official opinion finding that PGT is ethical for adult-onset disorders when there are no known treatments, or interventions are ineffective or significantly burdensome. In the United States, ultimately the decision about whether to do PGT for an adult-onset disorder is between you and your doctor. Regulations vary in other countries, and there may be more regulations for PGT with adult-onset disorders, which require citizens to seek out services within other countries such as the U.S.
Cost. IVF with PGT may not be covered by your insurance, and the process can be expensive. It’s important to learn the costs in advance and discuss financial options.
Do you want to know your genetic test results?
When you choose to undergo PGT, you are tested for the specific genetic mutation you want to avoid passing on. You have the choice whether you want to know your own results. Some people want to be aware of their risk, while others would prefer not to know if they’re likely to develop the condition being tested. If you learn that you don’t have the specific mutation which is known to cause the disease in your family, you don’t risk passing on the condition and continuing with the PGT process is not necessary. If you do have the mutation, your care team can discuss the possibility of passing on the disease.
Not everyone wants to know if they have a mutation, particularly in cases of neurological disease, so you have the option to undergo “non-disclosure PGT.” You won’t be told your results, and the PGT process will continue as scheduled. Your doctor also won’t disclose the number of healthy eggs retrieved.
Choosing to undergo PGT is a big decision. If you know you may be at risk of passing on an adult-onset disorder, consider making an appointment with a reproductive medicine clinic or a genetic counselor. Many families have successfully undergone IVF with PGT and gained the peace of mind knowing that their child won’t be at risk of developing certain heritable conditions. Working with your doctor and a genetic counselor will help you find the options that best suit your family.
Patricia Chaney is a freelance writer specializing in health and wellness. She has more than 10 years of experience demystifying health topics for people and promoting wellness. Her work has appeared on numerous health system websites and in industry journals. Ms. Chaney has a passion for health literacy, natural health, fitness, and food.