Archive for June, 2011

Genetic Tests: facts and fictions

Thursday, June 23rd, 2011

Are you more susceptible to developing cancer? Are you getting heart disease? Is obesity in your future? Your risk for many diseases and health conditions is just partly written in your genes. One day soon we will be able to visit our doctor and find out more about our health risks for the next years through genetic testing. But scientists (and I am included in this category) have many things to learn about genes before this becomes a reality. Genetic Testing regulation turned into a controversial topic after the FDA in the USA blocked some Over The Counter Predictive Tests and started paying more attention to this market. Several companies have been offering predictive genetic tests (examples are 23andme, Navigenics, Pathway Genomics, and others); however the tests they offer can be misleading in some cases. This is mainly because the environment plays a role in complex conditions. Genetic Tests for monogenic disorders such as Cystic Fibrosis, Huntington’s disease, etc are well established and reliable in most of the cases. In monogenic disorders, the affected individual will have a mutation or a genetic defect in a single gene or just a few making it easier to detect the underlying problem. In the case of predictive tests for complex diseases such as diabetes, cancer, arthritis, and others, several genes and the environment can affect the condition making it more difficult to get conclusions. I am not saying the consumer should avoid doing these tests; they just need to be careful and if some defect is detected they need to verify the veracity of it. Predictive Tests in some cases have a lot of support in the literature for the analyses, but in most of the cases there is no scientific evidence. Some say these tests are “recreational”. I think this is a start for an area that is not very explored yet. The companies offering these services have to mature and the beginning is always difficult. I believe that what needs to be done is a better explanation to the consumer on how these tests work, what they are really paying for and a better support after they get the results. Whole Genome sequencing companies such as Knome offer the sequencing of a person’s genome with a follow-up to explain the findings. In my opinion this is good; however there are a lot of regions in the genome that we do not understand yet. In fact, these companies are offering services coupled to research. The person that pays for whole genome sequencing will sign a consent form if he/she wants that the sequenced genome become public and available for research. Maybe that is a good way to better understand human genomes. In the case of genetic tests, the results could be a “Yes” or “No” answer but for most of them it will be a “Maybe”. This happens mainly because we are realizing that the environment has a big role in interacting with genes. In conclusion, the increasing need for regulation is a fact and there is still a lot of fiction in several of these tests that companies are offering (one example is the Genetic Tests for Sports Performance; well, genes are important, but the environment that can be exemplified by nutrition and training are also important factors). I believe we need to start somewhere and that is what is happening right now. Let’s see how the regulation will shape the genetic tests’ market from now on. I am curious…