Science Translational Medicine: High-Speed Test Can Diagnose Genetic Disorders in Newborns
New whole-genome sequencing technology can diagnose genetic disorders in newborn babies in intensive care units in just a few days, according a new study appearing in the 3 October issue of the journal Science Translational Medicine.
The technique’s main revolutionary feature is speed—a 50-hour turnaround time for genetic results compared to the few weeks needed using current methods. The genetic test could potentially shorten the time it takes to get a diagnosis, jumpstart any available treatments, and lessen the time to genetic counseling for anxious parents.
“These programs help us answer the question of what genes we should be looking at, what parts of the genome are relevant to the symptoms that a patient has, and what should we look at in more detail,” said Neil Miller, director of informatics at the Center for Pediatric Genomic Medicine at Children’s Mercy Hospital, during a 2 October teleconference with reporters.
In genetic diseases for which treatments exist, rapid diagnosis is critical for neonatal interventions. | Image © 2012 Sarah Maxey Photography
Called SSAGA, the technology allows any physician to order a complex genomic test with a few clicks. Using DNA extracted from a drop of the baby’s blood, computers analyze the child’s genome and map it to a set of nearly 7500 disease-related genes and genetic diseases, many of which may not familiar to the ordering physician.
Doctors then press buttons to enter data that represent the disease features they are seeing in a patient, and the system then looks for changes in the baby’s DNA code that explain his or her illness. The whole process is performed in roughly two days and is ideal for use in neonatal intensive care units. The researchers were able to make a definitive diagnosis in three out of the four babies they tested with the new technique.
Such rapid diagnosis can make a dramatic difference to a baby’s health. There are about 500 genetic diseases for which treatments are available. For example, phenylketonuria, or PKU, is a genetic disease that affects newborns and leads to intellectual disability and seizures. Yet early diagnosis and subsequent treatment (a diet lacking the amino acid phenylalanine) allows children to have a normal mental development and lifespan.
“Importantly, [the technique] also allows us to have accurate genetic counseling regarding the risk for parents to have another affected baby and make informative decisions about their reproductive future,” said Carol Saunders, clinical director at Children’s Mercy Hospital in Kansas City, Missouri.
“For example, we worked with a family to find a diagnosis, and they now know the gene that caused two stillbirths in the only two pregnancies that they have had,” Saunders added. “They are now pursuing genetic diagnosis so that they can have a healthy baby.”
The research team plans to broaden the test to 100 or more babies in order to pinpoint the exact benefits, costs, and potential problems of testing. The researchers also believe they can trim total testing time down from 50 hours to 36 hours by the end of the year.
Read the abstract, “Rapid Whole-Genome Sequencing for Genetic Disease Diagnosis in Neonatal Intensive Care Units,” by Carol Jean Saunders and colleagues.
Listen to a 2 October press teleconference with the article’s authors.