What’s in your genome?

With the completion of the human genome project in 2000 and advances in DNA sequencing technology it is now possible to have your own genome sequenced and discussions are starting to arise about whether it’s a good idea.

For most people it isn’t really a question, it simply isn’t affordable right now. But what if it was; would you get your genome sequenced and if you did what would you get out of it? Why shouldn’t you get your genome sequenced: What monsters do you have in your closet?

Your genome is the instruction manual required for you to live, to develop from a fertilized egg to a fully grown adult and then to maintain your body. All the processes that go on in all of your cells require different genes to be switched on at different times.

What kind of information can you get from sequencing your genome? You can get some information about your ancestry, some information about your physical characteristics and some information about diseases you might be prone to, very likely to get, or that you may pass on to the next generation.

The truth is that at the moment, we still don’t know a lot about what many of the genes in your genome do. This is something scientists around the world are working on but it will take a lot of time, or a much larger investment of resources, before we will have anything like a complete picture. There is also a lot of variation between different people and in only some cases (for some bits of the genome) do we know how important different changes are and what impact it might have on you. So you would be paying for a lot of information, much of which you can’t interpret, it’s just a long string of As, Ts, Cs and Gs.

Some people argue that it would give you vital information about what diseases you might be prone to, allowing you to take preventative measures. For most of us who don’t have a strong family history of anything, it would be far more effective to simply eat your 5 a day, take regular exercise, not take recreational drugs and not drink excessive amounts of alcohol. These are preventative measures everyone can easily take that will help everyone to stay healthy.

There are different versions of each gene, geneticists call these alleles, and there are some people who have a very high chance of developing a disease because of the particular version of the gene they have. In most cases if you are very likely to have inherited these genes you will know that there is a strong family history, the only additional information sequencing your own genome would give you is knowing for sure which versions of the gene you have. In some cases knowing this can be really useful, for instance individuals who inherit an allele that makes them prone to high cholesterol levels in their blood can be careful about their diet and there is medication they can now take as well.

Who does this information affect and can they handle it? In the case of Alzheimer’s having two copies of the epsilon 4 version of the ApoE gene will almost always result in a person developing the disease. Obviously this information affects you, as you get older will you wonder if the disease has taken hold every time you forget something? It also affects your partner, your children and your siblings. Your partner will know that they may end up caring for you and will have to face seeing you suffer from the disease. If you have two copies of this version then your children will know that they have at least one, as it’s the only version they could inherit from you. Your siblings will also know that both of your parents had this version of the gene, so the likelyhood that they too will have two copies is quite high. This could be the case even if neither of your parents had suffered from the disease.

There are other versions of the ApoE gene and they make it more or less likely that you may develop the disease, but at the end of the day it’s just an indication of the risk. You may or may not develop alzheimer’s so you’re not really any the wiser for having had your genome sequenced.

For people with a strong family history of a particular disease it isn’t necessary to get their whole genome sequenced to have this information, your doctor can request a genetic test to see which version of a particular gene you have. You can also be tested to see if you carry a disease related allele if it runs in your family, so that you can make more informed decisions about whether to have children and what tests to have during a pregnancy.

Having your genome sequenced isn’t a decision that should be taken lightly. If your doctor recommended a genetic test because of a family history you would receive counselling to help prepare you for the results, to understand what the results do and don’t mean and to help you cope with the impact. Private companies don’t offer this level of support, their priority is making money, not caring for you.

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One Response to What’s in your genome?

  1. Hi, I stumbled on this page from reddit. This isn’t not something I would regularly read, but I loved your perspective on it. Thanx for making a piece worth reading!

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