Can cheek swabs save babies’ hearing?

Summary: Valley Children’s Precision Medicine Program is pioneering a genetic test that quickly identifies infants at risk of aminoglycoside-induced hearing loss, allowing doctors to choose safer antibiotics.

Key relationships:

1. Rapid genetic testing: The test identifies MT-RNR1 gene variants in less than an hour, enabling timely and personalized treatment decisions for sick infants.
2. Prevention of hearing loss: Early identification of genetic risk allows doctors to avoid aminoglycosides, preventing potential long-term hearing damage.
3. Innovative care: This approach is part of a broader effort to integrate advanced genetic testing into patient care, improving outcomes for critically ill infants.

What if a gentle swab of a baby’s cheek was all it took to know if giving a common antibiotic could also lead to long-term hearing loss?

That’s what Valley Children’s Precision Medicine Program is doing: the team is the first in the country to use a revolutionary genetic test that can quickly let a doctor know if their little patient is at higher risk of hearing damage by a type of antibiotic known as an aminoglycoside. Once a doctor knows that the baby has a special version of the key hearing gene, he can choose a different course of care to treat an infection.

“Genes are like individual instructions in a book that tell the body how to build and work, so understanding them is important in creating a treatment plan for each patient,” says Jeremy Woods, MD, geneticist at Children’s Valley and director of Precision Medicine. Program in Madera, California.

Aminoglycosides and the risk of hearing loss

Aminoglycosides are a class of antibiotics often used to treat infections in infants in the neonatal intensive care unit (NICU). But in addition to attacking bacteria, the drugs can also attack human proteins that are vital for hearing development. This is usually not a problem, but for babies born with certain variants of the MT-RNR1 gene, the risk for aminoglycoside-induced hearing loss (AIHL) is much greater. Insights suggest that this may account for at least 1% of hearing loss that occurs in children before language development, and likely more.

The problem until now was to quickly check the baby’s genetic “map” if he got sick. Valley Children’s has solved this with a simple, non-invasive test. A small sample of saliva from the baby’s cheek is then analyzed by a special machine that tests for changes in the MT-RNR1 gene. The machine is no bigger than an inkjet printer and can deliver results to doctors in less than an hour when time is of the essence. The Valley Children’s Precision Medicine team is performing rapid MT-RNR1 testing for outpatients, with plans to standardize the process for in-hospital infants later this year.

“Previously, we would have to wait weeks for MT-RNR1 genetic test results. Now, we can have results in less than an hour,” says Woods. “That gives us plenty of time to choose a safer antibiotic to treat a critically ill baby.”

Valley Children’s Precision Medicine Program Innovations

This life-changing breakthrough is one of several innovative tools pioneered by Valley Children’s Precision Medicine Program. Earlier this year, the hospital began using an advanced genetic testing module as part of its electronic patient information system. This system allows providers to effortlessly order a comprehensive genetic test (whole genome sequencing) involving one or both parents and provides immediate care recommendations based on the child’s specific genetic map.

Valley Children’s was also one of only five institutions to participate in a Medi-Cal pilot program called Project Baby Bear, which used rapid whole-genome sequencing to improve care for critically ill infants with undiagnosed illnesses.

“Standard genomic testing in the NICU underscores our commitment to using the latest technology and genetics to provide our patients with more than the best care, but the specialized type of care they need,” says Woods.