Preimplantation genetic testing (PGT) has existed for more than 25 years and is a process that allows parents to screen embryos for potential serious genetic conditions. As our understanding of inherited diseases continues to grow, so do possible PGT applications.
Most organizations support PGT applications to test for severe, inherited childhood disorders. However, the choice to undergo PGT for adult-onset disorders raises questions regarding the ethics of screening for a disease that may or may not have an effective treatment in the future.
The American Society for Reproductive Medicine, an organization fundamental in establishing legislation behind reproductive rights, has weighed in regarding the appropriate uses of PGT.
Diseases Identified by PGT
Childhood Disorders
PGT for single gene disorders has commonly been used to test embryos for childhood conditions that develop within the first few months or years of life. These can be debilitating and result in a shortened lifespan, including:
- Cystic fibrosis
- Muscular dystrophy
- Spinal muscular atrophy
- Tay-Sachs disease
- Thalassemia
- Sickle cell anemia
- Fragile X syndrome
Many conditions have limited treatments that aim to keep symptoms at bay but don’t offer a cure. Some disorders, like muscular dystrophy and Tay-Sachs disease, are progressive, meaning that symptoms worsen over time.
Adult-Onset Disorders
As genetic testing advances, doctors can also test for inherited mutations that could lead to adult-onset disorders, including:
- Hereditary breast and ovarian cancer syndrome, mainly caused by BRCA mutations
- Lynch syndrome
- Familial Alzheimer’s disease
- Huntington’s disease
- Inherited heart diseases
A child may be born with a genetic mutation that predisposes them to develop the disease, but it will likely be decades before they experience any symptoms.
What Is the ASRM’s Stance?
Comprised of multidisciplinary members, including gynecologists, embryologists, and mental health professionals, the American Society for Reproductive Medicine (ASRM) is dedicated to maintaining a high level of ethics in reproductive medicine.
In 2013, the ASRM released its official opinion on PGT: The society believes that PGT is ethically justifiable for adult-onset conditions when there are no known interventions, or the interventions are ineffective or significantly burdensome. Determining what is significantly burdensome is left to the doctor and patient.
However, the ASRM acknowledges that some people could choose to undergo PGT for conditions that do not guarantee symptoms in adulthood that will be severe; some adult-onset conditions only increase the risk for symptoms to occur in adulthood, and the level of severity is unpredictable.
Public Opinion on PGT for Adult-Onset Disorders
A study released in 2015 by the U.S. National Library of Medicine sampled the opinions of more than 1,000 people on PGT. While there was overwhelming support for the use of PGT to determine childhood-onset disorders, there was significantly less support for the identification of adult-onset disorders.
The study attributes this lack of support to the fact that individuals may have different experiences with diseases, and they may have varying opinions on what constitutes a fatal or non-fatal disease. Additionally, the study notes that opinions varied depending on the gender, race, and education of the respondents.
PGT Testing for Adult-Onset Disorders
There are many couples who have chosen to do PGT for adult-onset disorders. Kris and Katie Cox, for example, who spoke to Genome, had used PGT to test for a severe kidney disorder that manifests in adulthood. The mother had the hereditary disease and felt that the eventual financial and emotional costs of the treatment justified going through PGT. Another couple, Whitney and Brittany, used PGT to have a healthy baby boy, free of the BRCA mutation that was carried by Whitney and his side of the family.
The opinions of different organizations are not legally binding within the U.S., and the decision to undergo PGT for an adult-onset condition ultimately lies with the individual or couple, along with their doctor.
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.