Gene That Makes Some Susceptible to Middle Ear Infections Discovered

Multiple genetic variants within the FUT2 gene that makes some people especially susceptible to middle ear infections discovered by scientists at the University of Colorado Anschutz Medical Campus.

"Middle ear infections are very common //in kids," said the study's lead author, Regie Santos-Cortez, MD, PhD, associate professor of Otolaryngology at the University of Colorado School of Medicine. "By the time they are 1-year-old around half have fever, ear pain or pus/fluid in the middle ear due to infection. Some of these infections may recur or become chronic thus requiring surgery."

Acute Ear Infection / Ear Discharge - Causes FAQs
Ear infection is very common in babies and young children. The type of ear discharge depends on the underlying cause.

‘FUT2 gene modifies the microbiome of the middle ear in a way that makes it more susceptible to infection by specific bacteria.’

Tweet it Now

The FUT2 gene is expressed in the salivary gland, colon and lungs but its expression in the middle ear has not been described previously.

Santos-Cortez and her colleagues discovered the role the gene played in middle ear infections or otitis media by initially examining DNA samples from 609 multi-ethnic families with the condition.

The study was published online today in the American Journal of Human Genetics.

Quiz on Ear Infections
Ear infections are generally classified depending upon the part of ear affected. They mostly affect the ear canal and the middle ear. Test your knowledge on ear infections by taking this quiz.

The researchers found common variants of the gene in Filipinos and South Asians and a rarer variant associated with recurrent middle ear infections in European-American children. The most common variant occurs in 30-50% of individuals in almost all population groups except East Asians.

"A number of things predispose people to getting these infections including a lack of vaccinations, lack of breastfeeding and being around smoking caregivers," said Santos-Cortez, who is also with the Center for Children's Surgery at Children's Hospital Colorado. "But even in the best case scenario, recurrent or chronic middle ear infections still happen in some kids, which may be due to genetic predisposition."

Ear Infections can Result in Neurological Complications
Neurological complications, including hearing loss, facial paralysis, meningitis and brain abscess can occur due to improper ear infection treatments, finds a new study.

Those who possessed the genetic variants had a much higher chance of getting the infection. "If you have these mutations, you will have a slightly different microbiota which could elevate the risk of disease," Santos-Cortez said.

The finding could eventually lead to new ways of determining who is likely to get the infection. The study confirmed expression of FUT2 in the middle ear which is spiked within 24 hours of bacterial infection. But the FUT2 genetic variants decrease presentation of A antigen used by bacteria to gain access to the middle ear lining.

New Instrument to Diagnose Ear Infection
In the U.S. nearly 2 million cases per year are incorrectly diagnosed and unnecessary antibiotics are prescribed causing, antibiotic resistance.

That causes a decrease in some bacteria while boosting the numbers of bacteria known to play a role in chronic or recurrent disease.

"The frequency of population-specific FUT2 variants makes this gene a potential target for preventative screening and future treatments for otitis media, including modulation of the middle ear microbiome," the study said.

Source-Eurekalert