Human brain 'organoids' offer new insight into rare developmental disease
MDS is caused by a deletion of a section of human chromosome 17 containing genes important for neural development. The result is a brain whose outer layer, the neocortex, which is normally folded and furrowed to fit more brain into a limited skull, instead has a smooth appearance (lissencephaly) and is often smaller than normal (microcephaly). The disease is accompanied by severe seizures and intellectual disabilities, and few infants born with MDS survive beyond childhood. In the new study -- published online January 19, 2017 in Cell Stem Cell -- the research team transformed skin cells from MDS patients and normal adults into neural stem cells, which they placed in a 3 dimensional culture system to grow organoid models of the human neocortex with and without the genetic defect that causes MDS. Closely observing the development of these MDS organoids over time revealed that many neural stem cells die off at early stages of development, and others exhibit defects in c...