Small differences in gene expression during development could increase or reduce the risk of getting sick. This was revealed by a study by the Universities of Chicago and Johns Hopkins.
The researchers analyzed stem cell RNA as they turned into heart cells. During the process, they identified hundreds of gene expressions in different sections of DNA. Expressions changed from individual to individual, determining part of the functions of the genes involved. According to the researchers, this could influence the likelihood of a certain disease manifesting itself.
The changes in question occur in the midst of development, often invisible in adult cells. Hence the need to observe stem cells during development. For this purpose, the researchers took RNA samples from the cells once a day for 16 days. In this way they were able to measure gene expression from day to day, so as to identify even the most subtle changes.
The RNA could explain why the risk of getting sick changes from individual to individual, even when there are the same genetic variants. Diseases such as diabetes, for example, are caused by the combination of genes and lifestyle. Lifestyle that involves minute changes in the way genes express themselves. This may one day help to more accurately identify those most at risk. For the moment, however, the whole process is too expensive.