I will have to admit that when I hear a little kid scream all crazy like when mom or dad leave the room, drives me absolutely bonkers! But; little did I know that this separation anxiety could be due to extra doses to a particular gene. On chromosome 7 there is a gene called GTF2I. When people miss parts of that chromosome that contain GTF2I, they usually get diagnosed with a condition called Williams Syndrome, and are generally extra social people. On the negative side, people who have extra copies of that part of chromosome 7 tend to have anxiety. According to Lucy Osborne of the University of Toronto, “about 26 percent of of children with an extra copy the region containingGTF2I have been diagnosed by a doctor as having separation anxiety”. Research was done on lab mice that had been genetically engineered with, three or four copies of the GTF2I gene, missing one copy of the gene, or the normal (~2) copies of GTF2I genes. The mice with the normal two copies of the gene squeaked 192 times over four minutes, when taken away from their mother. Mice with double the gene squeaked almost twice as much, and he one’s missing a copy were not as vocal. This test showed that separation anxiety and a few other kinds of anxiety could be a mental illness link up with how our genes are expressed.