According to a story from EurekAlert!, scientists have always sought to improve their understanding of the role that the environment and genes play in different diseases, as well as the interplay between the two. A great many rare diseases, for example, are caused by genetic mutations, but the impact of environmental factors on many of these diseases is still unknown. Recently a team of researchers from the Australian University of Queensland and the Harvard Medical School have come together in an attempt to learn more.
Drawing upon a huge trove of data from insurance databases, the team analyzed data from almost 45 million people. Within this group also included thousands of pairs of twins, both identical and fraternal. With this data the researchers attempted to look at the impact of both environment and genetic factors in 560 different diseases. The study was first published in the scientific journal Nature Genetics.
The scientists claim that this study comprises the largest analysis of twins so far. The researchers looked at a total of 56,000 pairs of twins. This study also goes against the traditional research approach by looking at many different types of diseases at once instead of just focusing on one. While it is common for the cause of a diseases to be labeled as the result of environmental factors or genetic factors, the reality is a bit more complicated.
While it is common for genes or environment to play a dominant role in the origin of a certain disease, there is often some degree of interaction and interplay between these two factors. In the past, it has been practically impossible for scientists to decode exactly how these two factors play a role in a given disease, but the researchers think that this large scale approach could be effective.
The study found that around 40 percent of the diseases looked at were influenced by genes and 25 percent were influenced by characteristics from a shared environment. Disorder affecting cognition were the most strongly affected by genes; in contrast, connective tissue diseases showed the least amount of genetic influence. Diseases affecting the eyes and respiratory system were the most strongly influenced by the environment. The study also found that 145 of the diseases studied were impacted by socio-economic status.
This study provides a useful snapshot of how genes and environment affect different diseases.
Check out the abstract for this study here.