By Diane Allingham-Hawkins, PhD, FCCMG, FACMG, Senior Director, Genetic Test Evaluation Program and Technical Editing
A recent article in The Wall Street Journal (WSJ) drew attention to a little-known unintended consequence of genetic screening, including, but not limited to, newborn screening: patients who test positive for presumably pathogenic genetic variants but who have no clinical symptoms of the associated disease. The article refers to these patients as “patients-in-waiting.”
Newborn screening is a public health initiative that screens the more than 4 million babies born annually in the United States. The number and types of diseases screened vary from state to state but the recommended “uniform newborn screening panel” lists 30 disorders, including biochemical disorders (e.g., phenylketonuria), hemoglobinopathies (e.g., sickle cell anemia), multisystem disorders (e.g., cystic fibrosis), and congenital hearing loss. The goal of newborn screening is to identify infants with health issues very early in life so that treatment or other interventions can be initiated as soon as possible. More information on newborn screening is available on the website Baby’s First Test.
Screening for genetic conditions may also be done in other instances such as when a particular condition is present in the family (e.g., cardiac conditions such as hypertrophic cardiomyopathy) or using more broad-based methods such as whole exome or whole genome sequencing or direct-to-consumer (DTC) genetic tests.
According to the WSJ article, however, an increasing number of screened individuals are told they carry genetic variants that predispose them to a particular disorder but currently have no symptoms. These patients-in-waiting may or may not ever develop the condition but they live their lives in a kind of medical limbo, wondering if or when the disease will develop. In addition, doctors are often unsure whether starting treatment will stop or delay the disease’s onset.
Situations such as these are only sure to increase as genetic testing technology rushes headlong toward the use of whole exome or whole genome sequencing for clinical purposes. Indeed, the National Institutes of Health (NIH) recently committed $25 million over 5 years to fund 4 centers to explore the use of whole genome sequencing in newborns. At the same time, professional organizations such as the American College of Medical Genetics and Genomics (ACMG) have published controversial guidelines about how physicians should handle so-called “incidental findings”—findings that are unrelated to the reason for performing the test but that may be clinically relevant to the patient or their family—that are discovered during clinical whole exome and whole genome sequencing. While the ACMG promotes a minimum list of incidental findings that its members believe should be disclosed to patients, concerns have been raised about informed consent, patient autonomy, and the resources required to support patients following disclosure of these incidental findings.
So, what does all of this mean? At Hayes, we believe that it is critical that the risks, benefits, and limitations of any genetic or genomic test are carefully considered before it is used in clinical testing. Receiving information that is difficult to interpret or understand is stressful for patients and their families and there are sure to be costs to the healthcare industry as we care for these “patients-in-waiting.” We urge caution and a consideration of all of the implications of implementing broad-based genetic testing in newborns or the general population at large.