Genetic epidemiology of obesity 2

Published on November 30, 2015   37 min

Other Talks in the Series: Obesity: Science, Medicine and Society

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Moving on to a new era, it's 2005. So in 2005 there was a major change. And again, that change was driven through advances in technology.
In 2005, the genome-wide association approach was introduced and genome-wide association as oppose to genome-wide linkage allows you to identify more exact chromosomal locations because you can screen a genome with higher resolution.
Genome-wide association is also hypothesis generating but it has a much higher resolution than genome-wide linkage. It's always designed as a two-stage design as opposed to genome-wide linkage. It has a discovery stage and whatever is discovered needs to be replicated within the same study. And I'll come back to that in the next slide. And genome-wide association studies turn out to have large sample sizes. And the reason for that is that very early on genome-wide association studies were very expensive. The chips that where designed to do these genotyping were extremely expensive, so people realized that to get a return on their investment they needed to collaborate. And that has lead to currently very large collaborations in large consortiums. Genome-wide association is the result of advances in technology. Predominately the advances in the genotyping technology which allowed to generate catalogues of genetic variation. And I'm showing you a few pictures of the Human Genome Project, the HapMap project, the 1000 genomes project. These are projects that have generated catalogues of genetic variations throughout the year. So the Human genome project was the oldest and then international HapMap and 1000 genomes are more recent and more complete ones. But these catalogues have allowed companies to develop these high-throughput genotyping SNP chips. You see these pictures of these chips that allow you to genotype hundreds, thousands, up to millions of variants in a very short time period.