Este texto foi traduzido/reescrito a partir de um texto no dia 23/09/2008 chamado “Genoma pessoal: o mapa astral do futuro” para ser submetido ao OpenLabs 2008.
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Companies that promise to analyse your genome are getting more and more popular. Today, you may hire one for only U$399. The company will send you a kit for you to collect your own DNA and send it for analysis.
The promise is to give you your own personal genome. However, instead of sequencing all your DNA, what those companies actually do is look for thousands of molecular markers in you DNA and throw back a bunch of random information (to which race your sequences are associated, the chances of developing certain diseases, how similar you are to your relatives and other people on their database, etc.).
These molecular markers are natural variations on certain DNA sequences of a given population. For example: the hypothetical gene XTX may have the sequence AATTCCGG or ATTTCCGG in it. The change in the second A to a T may not change anything in your physiology but it might give a clue about your genetic background. Having the first sequence may indicate an association to an Asian heritage or it may be associated to a high prevalence of breast cancer.
What should be noted is that the presence of a certain molecular marker in your genome does not determine your fate. For example, a molecular marker that is associated with breast cancer only suggests that you have an increased chance to develop this disease. If you were a 1000 individuals, we could say most of them will have breast cancer. But you are only one and these statistics apply poorly to individuals. You could end up dying of cancer but you a meteor could also fall in your head tomorrow.
Of course there are markers that are strongly correlated to important and fatal diseases. However, these markers are probably patented and the personal genomic company wouldn’t have screened for those in order to reduce the cost of the analysis. One cheap alternative to personal genome is what doctors do nowadays: look to your relatives and their medical records. If all your first-degree relatives wear glasses, guess what are your chances to use as well? If a lot of ancestors have died of due to diabetes complications, guess who has to pay attention to their own blood sugar? When doctors ask all those questions when you first meet them they are cheaply analysing your genetic background and looking for markers.
Thus, paying for your personal genome today has no practical finality other than personal curiosity (How similar am i to my brother? Do I have more African or Asian genes?). For me, it is like a modern astrological chart. Indeed, I predict that, in the next few months, a Hollywood star will say in national TV that he stopped eating sugar because his personal genome told him that he WILL have diabetes. Another one will end her career earlier to prepare herself for her Alzheimer years. In a few years we may read in the cover of some magazines things like: “Test whether your MHC is compatible with your fiancee’s” or even “If you carry the BZDDE marker, take care of your stomach this month. Beware: someone will cheat on you.”
Welcome to the Age of the Genome Horoscope.

markresch (FLICKR)