Genes & Cells

Scientists say no to genetic testing
Genetic tests marketed to consumers are misleading and should be banned, European scientists say in two studies presented in Amsterdam May 31 at the European Human Genetics Conference. Rachel Kalf of Erasmus University Medical Center in the Netherlands and colleagues found that one genetic-testing company predicted disease risks greater than 100 percent for five of eight diseases studied. A 100 percent risk means a person will definitely develop the disease. Researchers from the University of Leuven in Belgium surveyed 131 European geneticists and found that a majority believe most genetic tests for consumers should be banned, except for ancestry testing. —Tina Hesman Saey

How flu triggers asthma
Influenza viruses may dupe parasite-fighting cells into causing asthma. Researchers used to think that overreacting immune cells called T cells were the cause of flu-induced asthma. But mice infected with flu viruses can still get asthma even without T cells, researchers from Children’s Hospital Boston and colleagues report online May 29 in Nature Immunology. The researchers traced the source of the asthma to recently-discovered immune cells called natural helper cells and to chemicals called IL-33 and IL-13 in the lungs. The chemicals trigger increased mucus production and cause muscles to contract, which is helpful for expelling intestinal parasites, but leads to constricted airways and breathing problems in the lungs. —Tina Hesman Saey

Small RNA spurs Alzheimer’s disease
A mysterious piece of RNA may help cause Alzheimer’s disease by making an evil-twin version of an important brain protein. A piece of RNA, designated 38A, causes cells to make an alternative version of the KCNIP4 protein, researchers in Italy report in the May 30 Journal of Cell Biology.  The normal protein helps brain cells send electrical signals in a regular pattern to other brain cells. The alternate version of the protein short-circuits the electrical signal and may lead to the buildup of proteins associated with Alzheimer’s disease. —Tina Hesman Saey