Breast-feeding overcomes a genetic tendency toward ear infections, scientists discover

Dec 09, 2006

Breast-feeding protects children otherwise made susceptible to ear infections by abnormalities in specific human genes, researchers at the University of Texas Medical Branch at Galveston have discovered.

About 19 percent of children are prone to chronic and recurrent ear infections (known to physicians as "otitis media"). These infections can interfere with language development and lead to learning difficulties. Scientists have long known that genetics plays a role in this vulnerability, but very few investigations have been done to pinpoint the specific genes involved. Their complex relationship with specific infectious agents and environmental factors such as exposure to cigarette smoke and breast-feeding also has remained largely a mystery.

The UTMB study, published in the December issue of the journal Pediatrics, examined genetic samples taken from 505 children in Texas and Kentucky, about 60 percent of whom were classified as "otitis media susceptible" because they had suffered an ear infection before the age of 6 months; had undergone three or more episodes of acute otitis media within a six-month period; had four or more episodes within a 12-month period; or had six or more episodes by age 6. Children who had required drainage tubes to assuage recurrent or persistent ear infections were also placed in the "susceptible" category.

"We know that the tendency to get this infection runs in families, and so we decided to look for small variations — what we call ‘single-nucleotide polymorphisms,' or SNPs — in three important genes that produce inflammatory signaling molecules for the immune system," said lead author Janak A. Patel, a professor in the infectious disease division of UTMB's Department of Pediatrics. "Two of them stood out on their own as signals of increased risk."

The two identified genes generate the immune proteins known as tumor necrosis factor alpha (TNF-alpha) and interleukin 6 (IL-6). SNPs in each individual gene were enough, the researchers found, to create increased risk for childhood ear infections, and simultaneous SNPs in both genes created even more risk. The researchers believe that the particular variations detected cause greater production of inflammatory signaling molecules and reduce immune system effectiveness. But the UTMB scientists found that the effect could be counteracted with a practice long known to increase immune resistance: breast-feeding.

"This is a major finding, that breast-feeding neutralized the effect even in kids who had all the genetic polymorphisms," Patel said. "Not only that, they were protected from recurrent infections even later in childhood, long after they stopped breast-feeding."

By contrast, the group found that another environmental factor — exposure to cigarette smoke — increased vulnerability to otitis media in children with the TNF-alpha gene variation. Cigarette smoke exposure alone, however, was not enough to increase risk for ear infections.

Source: University of Texas Medical Branch at Galveston

Explore further: Growing a blood vessel in a week

add to favorites email to friend print save as pdf

Related Stories

Microsoft beefs up security protection in Windows 10

4 hours ago

What Microsoft users in business care deeply about—-a system architecture that supports efforts to get their work done efficiently; a work-centric menu to quickly access projects rather than weather readings ...

US official: Auto safety agency under review

17 hours ago

Transportation officials are reviewing the "safety culture" of the U.S. agency that oversees auto recalls, a senior Obama administration official said Friday. The National Highway Traffic Safety Administration has been criticized ...

Out-of-patience investors sell off Amazon

17 hours ago

Amazon has long acted like an ideal customer on its own website: a freewheeling big spender with no worries about balancing a checkbook. Investors confident in founder and CEO Jeff Bezos' invest-and-expand ...

Ebola.com domain sold for big payout

18 hours ago

The owners of the website Ebola.com have scored a big payday with the outbreak of the epidemic, selling the domain for more than $200,000 in cash and stock.

Recommended for you

Growing a blood vessel in a week

Oct 24, 2014

The technology for creating new tissues from stem cells has taken a giant leap forward. Three tablespoons of blood are all that is needed to grow a brand new blood vessel in just seven days. This is shown ...

Testing time for stem cells

Oct 24, 2014

DefiniGEN is one of the first commercial opportunities to arise from Cambridge's expertise in stem cell research. Here, we look at some of the fundamental research that enables it to supply liver and pancreatic ...

Team finds key signaling pathway in cause of preeclampsia

Oct 23, 2014

A team of researchers led by a Wayne State University School of Medicine associate professor of obstetrics and gynecology has published findings that provide novel insight into the cause of preeclampsia, the leading cause ...

Rapid test to diagnose severe sepsis

Oct 23, 2014

A new test, developed by University of British Columbia researchers, could help physicians predict within an hour if a patient will develop severe sepsis so they can begin treatment immediately.

User comments : 0