Wednesday, February 25, 2009

The Verdict on Autism

Finally we can get down to some real issues regarding autism. As reported in this editorial in the Los Angeles Times, the US Court of Federal Claims has found no substantiated link between autism and the MMR vaccine or the vaccine additive thimerosal.

I have covered autism in two previous posts "The Question of Fragile X " (9/27/2008) and "Autism in the News " (4/4/2008). In both cases I have discussed some of the genetics behind this disease. For example Scientists know that autism is a multifactorial trait - meaning that it probably has both a genetic and environmental component. It is also most likely that autism is a disease that displays genetic heterogenity - meaning that it is actually several different diseases that express themselves the same way. Cancer is a good example of a disease with genetic heterogeneity - just because you get cancer does not mean that it is from the same cause.

Should we have never investigated the MMR vaccine or thimerosol? - of course not. It is always important for scientists to follow-up any leads as to a cause of a complex disease such as autism. However, numerous studies have indicated that the link between these and autism is almost insignificant. So why is this an issue? For too long the research community has been having to focus on only one cause - vaccines and their additives. This focus on one factor is not resource-friendly and it distracts from the search for a real cure. The results are in - time to move on.

There will be those individuals who accuse the government, CDC, and pharmaceuticals of a massive cover-up. Others will decide not to vaccinate their kids based on religious preferences. Neither of these two groups should be treated seriously since 1) our government is not smart enough to cover-up the simplest lie, and 2) the consequences of not being vaccinated far, far outweigh the risks.

We need to support autism research, even when the results do not match what we want. That is what science is all about.

Want more information - check out the National Institutes for Health pages on autism and the National Autistic Society page on autism genetics.

Saturday, February 21, 2009

Neandertals in Our Midst

The commercials featuring the Geico caveman made it seem as if a Neandertal could readily interact within a Homo sapiens society.... we may soon find out if that is true.

Recently, scientists at the Max Plank Institute of Evolutionary Anthropology in Leipzig Germany announced that they had completed the sequencing of the Neandertal genome.

Neandertals went extinct around 30,000 years ago - most likely because of an untimely interaction with the Cro-Magnon, our early ancestors. As was the case with most species on the planet, Neandertals did not fare well from their encounters with us. For some time scientists have believed that it may have been possible that Neandertals simply bred into the Cro-Magnon population and the two became genetically integrated. Based on the work of these German scientists, it is now clear that this did not happen. There is no significant evidence of a transfer of Neandertal genes into our species.

While nature intends for extinction to be permanent, our mastering of the molecular world has made it possible to bring some species back to life. Wolly mammoths, the dodo bird, and passenger pidgeons have all been nominated as species to be returned to the surface of the planet. We can now add a new species - the Neandertals.

Once the genomic analysis is complete, it may be possible to transplant Neandertal DNA into a chimpanzee, or even human, ovum. Since there is very little genetic difference between these three, there should be relatively few developmental probems. In fact, it is estimated that this could occur within the next few years at the nominal cost of around $30 million.

So what would we do with these Neandertals? We should decide that before we begin. Our initial instinct may be to put them in a zoo. But we should be careful about that decision. For although we may consider ourselves to be the evolutionary favorite - we may have just gotten lucky the first time. We now know that Neandertals possessed the gene for speech, FOXP2, and they had a larger brain size than ours, and had the at least the beginnings of culture. They may give us a serious run for our money this time around. Who knows, maybe this time they will let us integrate into their culture..... or maybe not.

Wednesday, February 11, 2009

Walmart Offers Genome Sequencing? Not Yet...But Maybe Soon

Within the next few years it may be possible to go to Walmart, pick up a gallon of milk, and then stop by and have your genome sequenced while you wait. Sound unbelievable? Recent developments in the sequencing of your genome may make this a reality in the near future.

A company called Complete Genomics has recently announced that they intend to market the $5000 complete genome sequencing package. $5000 is not cheap, but it is definitely cheaper than some of the earlier efforts at genome sequencing.

The Human Genome Project cost 2.7 billion dollars, or roughly $1 per nucleotide in our genome. If the claims by Complete Genomics are correct, then the cost of having your 3 billion (+) nucleotides in your genome sequenced is be reduced to around $0.000016 each. And that opens the door for some pretty interesting developments....

First of all is the fact that the $5000 genome will ignite a form of biotech price war. When the first wide-screen plasma TVs hit the market, their average price was well over $5000. Many people wondered who would pay that much for a TV? But, very quickly, the price came down to the point where now you can get a wide-screen plasma for around $500. The same thing should happen with genome sequencing. Competition and technological advances will drive down the price, maybe even to less than $500. There is already financial incentive, the Archon X Prize in Genomics is offering $10 million to the first company to sequence 100 human genomes in less than 10 days. This is still a formidable task, but so was getting around the world in less than 80 days to Jules Verne.

The availability of inexpensive and rapid sequencing of individual genomes will be a huge asset to companies who need large databases for genomics work. Once these large databases become available, extensive association studies of the human genome become possible. These studies have the potential to reveal rare gene combinations that may be associated with some forms of diseases. This, in turn, has the potential to facilitate the development of new treatment options. As in any scientific experiment, the larger the database, the greater the chance of finding something rare and interesting. Right now, we are limited the availability of these large databases by cost...but it looks as if that may be changing.

Of course, there are real ethical questions that need to be addressed, mainly to do with the confidentiality of the genetics information and who ultimately owns the rights to your DNA. After all, the insurance companies would love to know about that rare allele you are hiding that will not only shorten your life (and time paying premiums) and cost them thousands in medical costs. We should be cautious of who has access to this information, but not so overly cautious as to delay development time of new technologies. In the long run, the availability of inexpensive genomic sequencing will advance medicine in ways that are currently only science fiction.

For more information on the work being done by Complete Genomics, see the article by Peter Aldhous "Genome Sequencing Falls to $5000"