:19:40;09	others that are not.
00:19:47;20	the known functions of these genes, to begin to take the step after gene discovery to understand biology.
00:20:03;20	about what was gonna happen after that.
00:20:31;16	lead us to hypotheses about novel treatments.
00:20:39;22	you begin to realize pretty quickly that this is overly simplistic and there's some significant challenges.
00:20:56;08	was going to be reliable and reproducible, and we knew we had a path forward.
00:20:59;11	It was a gene, a sodium channel, SCN2A.
00:21:17;23	get us all the way around this circle to pathway very quickly.
00:21:22;19	And so, you know, very excitedly, we went into the office.
00:21:25;17	I was with a postdoc.
00:21:45;10	can have a successful collaboration I need to know some things.
00:21:54;10	where in the brain is having its effect.
00:22:04;15	and so if we just kind of randomly look at this we'll get some sort of phenotype.
00:22:08;21	I'll be able to show you something, an electrophysiological signature, or it'll change migration.
00:22:15;08	I don't know whether that has anything to do with autism.
00:22:17;01	And I... and I had two kind of reactions, simultaneously.
00:22:20;18	One was like, how in the world am I gonna tell you... we know so little about autism.
00:22:24;21	I can't tell you when and where.
00:22:30;15	the challenges of moving to genes to do biology that I really hadn't thought about.
00:22:53;04	and then to be able to move from that to identify targets.
00:22:59;28	all that Steve Waxman was telling me is that the brain is a lot harder than a kidney.
00:23:04;11	And the developing brain is a lot harder than just the brain.
00:23:13;23	a ton, honestly, about how the brain is built.
00:23:16;14	We don't have a full census of all the cells that go into the brain.
00:23:26;18	it is pretty primitive.
00:23:39;13	have multiple different effects -- they're highly pleiotropic.
00:23:51;00	is really relevant to the pathology of autism spectrum disorders.
00:23:54;28	So, in a... shortly after this conversation with Dr. Waxman, my lab took a turn.
00:24:29;10	was having its impact on disease pathology.
00:24:32;01	And so... so then the question is how we were gonna do that.
00:24:40;19	down the hall, Nenad Sestan, who remains at Yale.
00:25:01;20	didn't really have the tools in hand.
00:25:14;01	when genes are turned on and turned off in brain development?
00:25:22;26	of a developing human brain.
00:25:24;05	And he did it by taking 15 periods of development.
00:25:33;04	and they go all the way to over sixty years of age.
00:25:45;02	he dissected the brains into 16 identifiable, established anatomical regions.
00:25:52;21	And then he did expression analyses.
00:25:53;24	And he began to just build, as I said, this map, across development, of gene expression.
00:26:03;22	this question of when and where.
00:26:05;13	And the first idea that we had was to take the genes about which we had highest confidence.
00:26:18;03	stringent statistical threshold and were already obviously being identified in multiple different laboratories.
00:26:31;27	and we built co-expression networks.
00:26:33;16	So, we used the genes to seed these... the networks that are shown here.
00:26:47;25	we built a co-expression network.
00:26:54;11	may be connected, but, again, we wanted to understand something about autism risk.
00:27:04;18	ones that might be relevant to autism?
00:27:31;27	show up in those networks.
00:27:44;22	that was greater than expected by chance.
00:27:59;11	into just kind of four anatomical areas of the brain.
00:28:08;24	the deeper the red, the more significant the finding.
00:28:11;24	We found two periods right next to each other, one that was very highly statistically significant.
00:28:17;24	It was enriched for additional autism risk genes.
00:28:27;10	And that was in prefrontal cortex and primary motor cortex.
00:28:34;03	And so, here is just a drawing.
00:28:44;15	And this is the most enriched one that corresponds to this finding, here.
00:29:00;27	one that we were interested in, we could begin to ask questions about... about additional characteristics.
00:29:17;08	and that's represented down here.
00:29:20;25	But then we could go further and ask additional questions about that network.
00:29:24;02	So, we asked, if you looked at cortex, was that network present in all six layers of cortex?
00:29:30;11	And in fact it was not.
00:29:36;26	layers 5 and 6.
00:29:39;10	And... we also asked the question whether or not it was in all cell types in the cortex.
00:29:43;05	And we came up with the answer that it wasn't.
00:29:44;25	It was only in glutamatergic neurons in layers 5 and 6.
00:30:17;10	that we're looking at are mid-fetal human brain deep-layer cortex and glutamatergic projection neurons.
00:30:28;25	on how we were thinking about understanding pathology.
00:30:37;23	when and where is it going wrong?
00:30:44;10	they're involved in a variety of different functions from chromatin modification to synaptic functioning, etc.
00:30:49;13	What's bringing them together is not a pathway, not a protein-protein interaction.
00:30:53;24	What's bringing them together is the spatiotemporal distribution of risk.
00:30:57;20	So, I just want to summarize here.
00:31:12;22	characteristics of de novo mutation.
00:31:15;05	These are large effect mutations.
00:31:16;26	They are present in the coding portion of the genome.
00:31:19;06	And consequently give us a fairly direct pathway, now, to understand them at the bench.
00:31:35;23	but that's gonna really begin to hone in on pathophysiology.
00:31:48;02	biology that you might describe and the pathophysiology that we want to understand.
00:31:53;01	Already I've shown you that there is convergence, at least for a subset of autism genes.
00:31:58;05	This is unlikely to be the answer for all autism genes.
00:32:00;25	In fact, I would bet against it.
00:32:19;24	the tremendous opportunity to be successful in identifying novel treatments.
00:32:40;15	quite a different story, where we have many different potential targets that are coming up simultaneously.
00:33:05;12	in a way that will lead to the ultimate success in this research strategy.
00:33:11;20	This work was done by... by wonderful folks in the lab.
00:33:16;03	I particularly want to highlight the work of Stephan Sanders and Jeremy Willsey.
00:33:20;06	Stephan's name and Jeremy's you saw throughout the presentation.
00:33:29;23	from developing the analytic tools to writing the papers.
00:33:46;23	the role of de novo mutations to autism spectrum disorders.
00:34:00;04	Simons Simplex Collection and the other autism cohorts that... that I've talked about in this presentation.
00:34:08;26	So, thank you for your attention.
In the first lecture, Dr. Bryan King introduces the autism spectrum disorder (ASD) and defines the clinical criteria that characterizes ASD. Although there is no universal drug that is used to treat ASD, there are multiple medications used in the setting of autism. King