For Immediate Release: Thursday, October 22, 2026, 4:15 p.m. U.S. Eastern Time
Media Contact: Evelyn Mantegani, +1 240-833-2014, [email protected]
Presented By: Wendy Chung, MD, PhD, Boston Children’s Hospital, Harvard Medical School
Long QT syndrome is an inherited heart rhythm disorder that can cause life-threatening arrhythmias, but medications, cardiac monitoring, and avoidance of specific triggers can reduce risk. Results from a large genomic newborn screening study show that identifying the condition shortly after birth can guide preventive care for infants and uncover previously unrecognized risk among relatives.
The GUARDIAN study evaluated expanded genomic newborn screening at six New York City hospitals. Among the first 25,000 newborns enrolled, researchers identified pathogenic or likely pathogenic variants in the LQTS-associated genes KCNH2 and KCNQ1 in 30 infants, or approximately one in 800. This rate was higher than previous prevalence estimates. Follow-up information was available for 27 infants.
Electrocardiograms found at least one prolonged QT interval in 12 infants and borderline results in eight. Eight children began beta blocker therapy, and nearly all continue to receive cardiac follow-up.
Genetic testing showed that 26 infants had inherited their variant, while one had a new, or de novo, variant. Most families had no known history of long QT syndrome. Testing relatives resulted in six parents beginning beta blockers. An older sibling who had experienced fainting also started treatment after testing confirmed the familial variant and an electrocardiogram detected a markedly prolonged QT interval.
The findings demonstrate how genomic newborn screening for a preventable cardiac condition can inform immediate care while extending potential benefits to multiple generations of a family.
About the American Society of Human Genetics (ASHG)
The American Society of Human Genetics (ASHG) is the leading global organization advancing the science of human genetics and genomics. Representing nearly 8,000 researchers, clinicians, genetic counselors, educators, and other professionals, ASHG drives progress in understanding the human genome and its role in health and disease. The Society fosters innovation and collaboration through its flagship events and publications—including the ASHG Annual Meeting and its peer-reviewed journals The American Journal of Human Genetics and Human Genetics and Genomics Advances. ASHG also champions science advocacy, supports the next generation of genetics professionals, and promotes responsible policies and public engagement in genetics. Learn more at www.ashg.org.
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