0:04
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.
0:16
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.
0:34
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.
