Scientists identify single-gene mutations that lead to atopic dermatitis

Researchers have identified mutations in a gene called CARD11 that lead to atopic dermatitis, or eczema, an allergic skin disease.

Atopic dermatitis. Image credit: James Heilman, MD/Wikipedia (CC BY-SA 3.0)

Scientists from the National Institute of Allergy and Infectious Diseases (NIAID) and other institutions discovered the mutations in four unrelated families with severe atopic dermatitis and studied the resulting cell-signaling defects that contribute to allergic disease.

Their findings also suggest that some of these defects potentially could be corrected by supplementation with the amino acid glutamine.

The scientists analyzed the genetic sequences of patients with severe atopic dermatitis and identified eight individuals from four families with mutations in the CARD11 gene, which provides instructions for production of a cell-signaling protein of the same name.

While some people with these mutations had other health issues, such as infections, others did not, implying that mutations in CARD11 could cause atopic dermatitis without leading to other medical issues often found in severe immune system syndromes.

The scientists next set out to understand how the newly discovered CARD11 mutations contribute to atopic dermatitis. Each of the four families had a distinct mutation that affected a different region of the CARD11 protein, but all the mutations had similar effects on T-cell signaling.

With cell culture and other laboratory experiments, the researchers determined that the mutations led to defective activation of two cell-signaling pathways, one of which typically is activated in part by glutamine.

Growing cultured T cells from patients with CARD11 mutations with excess glutamine boosted mTORC1 activation, a key part of one of the affected pathways, suggesting the potential to partially correct the cell-signaling defects that may contribute to atopic dermatitis.

The scientists now are planning a study to assess the effect of supplemental glutamine and leucine, another amino acid that activates mTORC1, in people with atopic dermatitis with and without CARD11 mutations. (National Institutes of Health)

YOU MAY ALSO LIKE

Moderate calorie restriction in young and middle-aged adults significantly reduces heart and metabolic risk factors independent of weight loss

Moderately reducing caloric intake over a period of two years significantly improved cardiometabolic risk factors in young and middle-aged, non-obese adults, according to new findings from the Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy.

Parental obesity linked to delays in child development

Children of obese parents may be at risk for developmental delays, according to a study by researchers at the National Institutes of Health.

Mutated Terrestrial Bacteria That Return from Space Pose Threat to Life on Earth

Russian scientists believe that terrestrial bacteria that were sent to space and returned to earth now pose a threat to the existence of life on Earth.

Antarctic seals may use Earth's magnetic field to navigate while hunting

Weddell seals have biological adaptations that allow them to dive deep--as much as of hundreds of meters--while hunting, but also an uncanny ability to find the breathing holes they need on the surface of the ice. Now, researchers believe they have figured out how they do it--by using the Earth's magnetic field as a natural GPS.

Cradle of evolution for cold-adapted mammals is in Tibet

For the last 2.5 million years, Earth has experienced millennia-long cold and warm cycles. During cold periods, continental-scale ice sheets have blanketed large tracts of the Northern Hemisphere.

New sea slug species discovered near condominiums of Florida’s Cedar Key

Feet from the raw bars and seashell-colored condominiums of Florida's Cedar Key, NSF-supported researchers at the Florida Museum of Natural History and California State University discovered a new species of sea slug that is a rare outlier in a group famous for being ultra-vegetarians.