2025 studies in the dozens support genome-first testing in rare disease
Testing company pushing genomics approach to ID conditions like AADC
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Over the course of 2025, U.S.-based Genedx published dozens of studies powered by its rare disease genomics dataset — which, by the numbers, the testing company claims, shows the effectiveness of a genome-first approach.
Genomics is the study of an organism’s entire genome, essentially all of its DNA. This varies from genetics, which typically focuses on the study of individual genes.
According to Britt Johnson, PhD, senior vice president of medical affairs at Genedx, the company’s research “doesn’t just advance scientific understanding – it changes clinical practice.” In a company press release, Johnson said Genedx is working to make genomics the standard of care in rare disease research.
“In 2025, we showed at unprecedented scale how a genomic-first testing approach delivers precise diagnoses, greater equity, and more confident care decisions,” Johnson said.
Among the most influential publications leveraging Genedx’s technology was a study published in JAMA that reported early findings from an ongoing clinical trial called GUARDIAN (NCT05990179), fully Genomic Uniform-screening Against Rare Disease In All Newborns.
Newborn screening involves systematically testing all babies for congenital diseases, allowing children to be diagnosed and start appropriate treatment as early as possible. Currently, newborn screening programs in the U.S. test for a few dozen conditions, primarily by analyzing levels of specific molecules in the blood.
However, there are thousands of rare genetic diseases, such as aromatic l-amino acid decarboxylase (AADC) deficiency, that aren’t included in most newborn screening programs.
GUARDIAN study testing feasibility of genome-first approach
Genedx is pushing a so-called genome-first model: Instead of testing for specific disease-associated molecules, newborns have their entire genetic code sequenced and compared against established datasets to look for any probable disease-causing mutations. Theoretically, this approach could enable the diagnosis of many more diseases with a single test.
We can deliver better care for patients through true genomic precision medicine.
The GUARDIAN study, sponsored by Columbia University, is testing the feasibility of this approach. The study aims to test an estimated 100,000 babies born in New York. The JAMA publication covered outcomes from the first 4,000 babies who underwent testing in the study. Among these infants, 120 were ultimately found to have a rare disease, and most of the diagnosed diseases were conditions that aren’t included on standard newborn screening panels.
“We can deliver better care for patients through true genomic precision medicine,” Johnson said.
Other studies published last year supported the utility of Genedx’s approach in specific situations, including both critical and non-critical pediatric patients and people with unexplained seizures, according to the company.
“With unmatched clinical depth, real-world evidence, and a proven ability to translate discovery into care, Genedx is paving the way for a genome-first healthcare system,” said Katherine Stueland, president and CEO of Genedx. “Through our research and collaborations, we are demonstrating how healthcare can work better for patients, enabling earlier diagnosis, precision care, and better outcomes the standard, not the exception.”
