Babies don’t wait until school to take their first test. In fact, their first few tests occur within the first several hours of life outside of the womb. No pressure, right?
The newborn genetic screen is one of the first and most important tests of a new baby’s life. This test is performed in every US state, although the number of conditions for which each state screens varies. The screen is designed to detect treatable genetic disorders that are not necessarily clinically detectable at birth; this early detection allows for diagnosis and for treatment to begin early in order to reduce or eliminate symptoms that could lead to long-term disabilities or even death.
The earliest version of this screen began in the 1960s when American microbiologist Robert Guthrie began using a test to detect levels of the amino acid phenylalanine in the blood of newborn babies. High level of phenylalanine could be an indicator of the metabolic condition phenylketonuria (PKU; more on this condition in a few weeks), and Dr. Guthrie knew that early treatment could help prevent the neurological symptoms that were associated with this condition as individuals grew older. He and his colleagues also began screening for congenital hypothyroidism in the 1970s, and further advances in technology allowed them to expand their screening efforts in the 1990s.
So how is this screen performed? All it takes is a small blood sample collected from the heel. This sample is collected from the newborn within the first day or two of life, typically when they’re still in the hospital. (In the case of births at home or at birthing centers, pediatricians or midwifes are typically able to perform the necessary blood draw, but this should be confirmed in advance. It’s better to have this screen performed as soon after birth as possible, so delays due to lack of materials, knowledge, etc. could potentially lead to significant issues down the road.) The blood sample is then sent to a laboratory for testing, with results returned within a few days or a week. Parents are usually only contacted with results if something of concern is found on the screen, and additional testing is then needed to officially confirm the diagnosis.
So what conditions are tested for? The newborn screen tests for rare genetic, hormone-related, and metabolic conditions including:
PKU
Maple Syrup Urine Disease (MSUD)
Congenital hypothyroidism
Congenital adrenal hyperplasia
Sickle cell disease
Cystic fibrosis
Severe combined immunodeficiency
Spinal muscle atrophy
Galactosemia
As I said, different states test for different things, but by 2011, all states reported screening for at least 26 conditions, including PKU and hypothyroidism. (For the list of conditions screened in your state, click here).
Newborn screening saves or improves the lives of more than 12,000 babies each year. Last year, one of those babies was my son, Mason. Three days after he was born, my husband and I received a call informing us that Mason had flagged for PKU on his newborn screen. My husband and I are trained scientists, and we had both heard of PKU before that call but had very little knowledge of the diagnosis. Even before we met with our geneticist and our dietician, we began researching the disorder on our own; it quickly became apparent that, although the news of Mason’s PKU seemed devastating and overwhelming, having an early diagnosis and being able to begin treatment was the very best thing for him. The newborn screen made all the difference in Mason’s health and ensured that he would begin life on the right track to become a happy, healthy little boy. Today, Mason is a happy thriving seven month old whose diet looks a little different than other infants his age, but he’s otherwise a normal, into-everything, drooly, smiley little guy.
The newborn genetic screen is, in my opinion, one of the most important public health initiatives in place today. Without Dr. Guthrie’s work as well as the continued efforts of medical and public health officials, rare genetic and metabolic conditions such as PKU would continue to negatively impact the lives of babies across the country. Luckily, this first test that babies take allows for these conditions to be diagnosed and treated early on, which makes all the difference in the lives of these little ones.
Do you have or does anyone you know have a condition discovered through the newborn genetic screen? Share below in the comments!