How Accurate is Newborn Genetic Testing?

Newborn screening considerations

According to the National Center for Health Statistics, nearly four million babies are born in the United States each year. It is reported that 98% of these children born are tested within the first few days of life for more than 30 types of medical conditions. An established newborn screening program initially began for testing phenylketonuria (PKU) by Dr. Robert Guthrie in the 1960s. Since then, screening tests have evolved to help parents become aware of potential conditions their child may have in order to provide preventative treatment.

Is Genetic Testing Mandatory at Birth?

Newborn genetic screening (NBS) is mandated by state, and therefore each state’s screening requirements are different. Some states allow parents to opt-out of testing, while other states require stricter stipulations for refusal. Along with the existence of newborn genetic testing has come ethical and legal concerns raised regarding the logistics and rationale for testing.

What does Newborn Screening Consist Of?

Though screened conditions are determined by each state, in general, there are 35 federally recommended conditions included in the screening panel consisting of, 9 organic acidemias, 5 fatty acids oxidation disorders, 6 amino acid disorders, 2 other inborn errors of metabolism, 2 endocrine disorders, 3 hemoglobinopathies, hearing loss, severe combined immunodeficiency, lysosomal storage disorders, congenital heart disease using pulse oximetry, and cystic fibrosis, and the most recent inclusion of spinal muscular atrophy in 2018.

Together, the Advisory Committee on Heritable Disorders in Newborns and Children and the Secretary of the US Department of Health and Human Services institute national guidelines for screening known as the Recommended Uniform Screening Panel (RUSP). Parents are able to look up which conditions their state tests for by visiting

Newborn screening consists of a “heel-stick” test where a small amount of blood is collected from the baby’s heel onto a piece of filter paper. This is done within the first 24-72 hours of birth. The genetic information from the cells is sent to a state-approved laboratory and taken from the dried blood sample. Results are typically released within 10-14 days, at which time your doctor will discuss if there is a need for diagnostic testing.

How Common are False Negatives in New Born Screening?

The makeup of genes and changes within genes can paint a picture of a child’s current conditions or inclination to develop future conditions. However, genes can change from lifestyle and environmental factors as well. It is important to keep in mind that screenings are only predictive tests to measure the likelihood, not the actuality, of a child having a certain disease. For these reasons, genetic testing cannot solely be used to make predictions about health issues with a high level of certainty.

Newborn state screenings

Are There Other Types of Newborn Genetic Tests Offered?

Some companies offer additional or supplemental testing beyond the state-mandated screenings. These tests are used to detect the likelihood of conditions that extend beyond the 30+ listed on the RUSP. Some parents choose to undergo these additional tests for the sake of knowing what their child may or may not have in the hopes of being better prepared both emotionally and resource-wise. While there are some benefits of more extensive testing, there are also certain disadvantages associated with these types of genetic tests. It is always best to consult with your child’s pediatrician to discuss these options. In general, supplemental testing is requested upon a pediatrician’s referral.

Parents should understand that genetic screening and diagnostic testing are vastly different approaches to uncovering conditions. Genetic screening is a tool doctors use in diagnostic testing; a precursor. Diagnostic testing can consist of reviewing personal and familial medical history, specialized physical examinations, imaging scans, and additional laboratory testing to determine a diagnosis (i.e., if a condition is present).  

Genetic tests are designed to detect gene variants associated with only certain genetic diseases. They cannot detect every variant associated with each disease, nor can they look for all known genetic diseases that could affect a child. Genetic testing will only report back genetic changes that indicate a child is affected with the disease, but it will not report back whether your child is merely a “carrier” of the variation associated with a disease. Likewise, a negative test result does not mean that your child cannot develop a condition that has been tested. Thus, some beg the question of whether it’s better to know or not to know.

What Are Some Risks Associated with Newborn Genetic Screening?

The proverbial can of worms that comes from the results of a test that are not conclusive or comprehensive can build unnecessary anxiety in expecting parents. Some of the conditions screened for in these supplemental tests are not included in state-mandated tests for specific reasons including, the lack of existing treatment possibilities, the risks of undergoing treatment, the onset of a condition does not present itself until later in life, or because the condition is non-threatening. Furthermore, as with most other types of screenings, false positives can occur. As one study reveals, in the case of testing with tandem mass spectrometry, for every one true-positive, there are an estimated nine false-positive results, as cutoff thresholds are generally set low to avoid missing affected infants. The anxiety induced by these tests can have emotional, financial, and, sometimes, harmful ramifications for both the parents and child.

As Rajani Aatre, M.S., M.Sc., and genetic counselor at the University of Michigan Frankel Cardiovascular Center explains it, “The science is easy to process; the emotional component is not.” Beyond the emotional fallout, there are other things to consider when looking into newborn genetic testing. As one source states, these tests may be “more controversial based on their cost, reliability, and predictive value, as well as the availability and success of treatment. This uncertainty about testing technology in a newborn context contributes to variation in both health care practice and state policy standards.”

In addition, some consider the fact that the DNA collected for screening can be kept indefinitely and be used for medical research. Screening companies are also able to give de-identified information to research databases for scientific or medical use, with no compensation to the child, often under limited regulation. Furthermore, if a parent chooses to have supplemental screening done, testing is not covered under the fees charged by each state for newborn screening. The costs of additional testing are charged by the laboratory that performs the tests and can run parents upwards of $600+ out-of-pocket.  

Screening may also reveal sensitive information about your child’s health, your own health, or that of your relatives. The “burden of knowledge” that comes along with testing results can have a significant impact on any parent’s emotional state. Thus, it is always recommended that you speak with your child’s healthcare provider when considering supplemental newborn screenings. Most often, if it is decided that your child may benefit from additional screening, you will be referred to a genetic counselor who can help you cope with a gamut of outcomes that may arise as a result of testing. 

A Warning from the FDA

According to a press release from the FDA, “Pregnant people have ended pregnancies based on the results of genetic prenatal screening alone, without understanding the limitations of the screening test and that the fetus may not have the genetic abnormality identified by the screening test.” The agency is also advising patients to take their time to discuss the benefits and risks of prenatal testing with a genetic counselor or a health care provider prior to making any decisions based on the results of prenatal testing.
Most Laboratory Developed Tests (LDTs) currently on the market are offered without any review by the FDA. According to the agency, LDTs are medical devices that have a general policy of enforcement discretion. This means the FDA is not enforcing applicable regulatory requirements for the LDTs. However, the FDA is working to make improvements to establish a modern regulatory framework for all testing being administered.
Currently the FDA is concerned that the laboratories who are advertising their services as reliable or highly accurate that the claims being made are not supported by scientific evidence. Some conditions are very rare and may not be included in the testing due to limitations. For example, when testing for a rare condition it is more likely to receive a false positive than a true positive result from these tests. Another result could show an abnormality, which may only be present in the placenta and not in the fetus.

What Questions Should I Ask My Pediatrician If I’m Considering Genetic Testing for My Newborn?

Questions for your pediatrician
  • Which conditions are screened for in my state?
  • Can additional screening benefit my child?
  • What happens if my child screens positive for a condition?
  • What consent is required for genetic testing?
  • Can my child’s results be subject to privacy violations?
  • What happens if I am found to be a genetic carrier?
  • What costs can I expect to pay?
  • Is a genetic counselor available for me? At what cost?
  • Does genetic testing make sense for my child?
  • Can test results dictate my child's health coverage?

Though newborn genetic screening can be beneficial for families wherein screening makes sense, supplemental genetic screening should first be discussed with your child’s pediatrician. There are several aspects to consider before jumping into additional screening beyond what is mandated. Navigating life as a new parent can be overwhelming, and there are many decisions to make. As always, we encourage parents to make informed decisions that best suit the individualized needs of their families.



Last Updated on: 09/29/2023 by Diane Paradise