Gene Technology Outperforms Standard Newborn Screening Tests in Pioneering Study

By LabMedica International staff writers
Posted on 05 Nov 2024

Image: Genome sequencing technology has the potential to detect thousands of genetic disease (Photo courtesy of 123RF)

Since its introduction in the 1960s, newborn screening has grown to encompass dozens of primarily genetic disorders. The standard approach to newborn screening involves detecting specific biomarkers in blood that are associated with various conditions. However, many diseases still lack identifiable blood biomarkers, which limits the effectiveness of current screening methods. In contrast, genome sequencing, which was once rare and prohibitively expensive, has become increasingly accessible and affordable for clinical use, making it a potentially superior option for newborn screening. This technique analyzes a newborn’s DNA to identify hundreds of specific gene variants known to cause diseases, with the capability to detect thousands of genetic disorders—far exceeding the approximately 60 conditions currently identified through standard newborn screening. The genes included in newborn screening can lead to diseases that, if diagnosed early in infancy, could be prevented or treated. Now, early results from a study on newborn screening methods indicate that DNA analysis identifies significantly more preventable or treatable serious health conditions compared to standard newborn screening and is preferred by most parents offered this option.

The GUARDIAN study, conducted by researchers at Columbia University Irving Medical Center (New York, NY, USA), is one of the first large-scale studies globally to utilize genome sequencing for newborn screening and is the first to publish preliminary findings. Launched in September 2022, the GUARDIAN study provided genome sequencing to every newborn at NewYork-Presbyterian hospitals in New York City. In its inaugural year, GUARDIAN assessed genes associated with 156 rare but treatable conditions. Parents had the option to include an additional panel of 99 conditions that currently lack treatments but may benefit from early intervention. The study utilized DNA from the same dried blood spots collected at birth for traditional newborn screening, which is processed for each participant by the New York State Department of Health’s Newborn Screening Program.

Out of 147 children who screened positive using genome sequencing, 120 were confirmed true positives and diagnosed with a rare condition, with only 10 identified through standard screening methods. Most of the children diagnosed with a genetic condition (92 out of 120) had glucose-6-phosphate dehydrogenase deficiency (G6PD), an enzyme deficiency not included in traditional screening. Individuals with G6PD deficiency can experience moderate to life-threatening reactions to specific foods and medications, which can be easily prevented by avoiding those triggers. In one instance, genome sequencing identified a critical condition—severe combined immunodeficiency disorder (SCID), often referred to as “bubble boy syndrome”—that was missed by standard screening. The presence of a rare genetic variant causing SCID was detected, allowing doctors to protect the infant from life-threatening infections before they could occur.

Overall, 3.7% of children in the study tested positive for a genetic condition. Excluding G6PD cases, the positive screening rate was 0.6%, which is double the 0.3% rate achieved through standard screening in New York state. Parental acceptance of genome sequencing for newborn screening was notably high, with 72% of families approached agreeing to participate, and 90% of participants opting for the additional screening for untreatable conditions. The GUARDIAN study is now investigating gene variants linked to more than 450 conditions, with dozens of new conditions being identified each year. The ongoing study aims to enroll 100,000 infants in the coming years to gain insights into parental perceptions regarding genome sequencing, the associated costs, privacy concerns, and challenges in interpreting results across diverse ancestral backgrounds.

“The results show us that genome sequencing can radically improve children’s medical care,” said Joshua Milner, professor of Pediatrics, director of Allergy/Immunology and Rheumatology at Columbia University Vagelos College of Physicians and Surgeons, and one of the study’s co-authors. “Genome sequencing allows us to detect things that cause serious illness and take action to prevent those illnesses in a significant number of children, not just a few rare cases. It should be instituted as the next standard for newborn screening because it can detect so much more than current methods.”

Related Links:
Columbia University Irving Medical Center