What Experiment Led to the Identification of the DSCR Down

Question

What experiment led to the identification of the DSCR Down Syndrome Critical Region ?
A)an extra DSCR was injected into yeast cells
B)transgenic humans were developed that had a duplicated DSCR
C)a mouse model was developed lacking the DSCR
D)cancer cells were sequenced to identify the VEGF gene
E)a mouse model was developed trisomic for the DSCR

Accepted Answer

A mouse model was developed that was trisomic for the DSCR, meaning it had three copies of the region instead of the typical two copies found in most individuals. This led to the identification of the DSCR as an area in the human genome that is critical for the development of Down syndrome.