Amsterdam, The Netherlands. Direct-to-consumer (DTC) genetic tests give inaccurate predictions of disease risks and many European geneticists believe that some of them should be banned.

Two different studies presented at the annual conference of the European Society of Human Genetics (ESHG) followed different routes to the same conclusion. One focused on the predictive ability of DTC tests, while the other surveyed clinical geneticists on their experience and attitudes.

University Park, PA, USA. Scientists assembled entire chromosomes in a test tube from their component parts, revealing the process a cell uses to package the basic building blocks of an organism's entire genetic code — its genome.

A procedure described in the journal Science allows scientists, for the first time, to do highly controlled biochemical experiments with all the components of an organism's genome.

Chevy Chase, MD, USA. A detailed comparison of DNA and RNA in human cells uncovered a surprising number of cases where the corresponding sequences are not identical.

The RNA-DNA differences generate proteins that do not precisely match the genes that encode them, suggesting that unknown cellular processes act on RNA to generate a sequence that is not an exact replica of the DNA from which it is copied.

Rochester, MN, USA. Researchers succeeded in switching individual zebrafish genes from off to on, then observing embryonic and juvenile development.

The result is a new tool for identifying protein function from genetic code. In the mammal mouse model, conditional alleles switch from the on position to off. The new tool reverses direction, with direct observation of gene switching from the off position to on, permitting finer investigations of localized gene requirements.

New York, NY, USA. The first large scale investigation to search for trauma-induced changes in the genes of people found that traumatic experiences are biologically embedded in select genes, altering their functions and leading to the development of post-traumatic stress disorder (PTSD).

PTSD may occur shortly after a major trauma and is usually of short duration, with relief after 3 months. However, delays in the onset of more than 6 months after the event can result in the longer-term form an