Virtually everyone with Williams Syndrome has exactly the same set of genes missing (25 to 28 genes are missing from one of two copies of chromosome 7). There also are rare cases of individuals who retain one or more genes that most people with the disorder have lost.
"I wanted to focus on something that could get me down to just a few genes related to behavior," says senior author Korenberg, also a USTAR professor of pediatric genetics at the University of Utah School of Medicine. "When it became clear that Williams Syndrome is caused by a microdeletion of genes, we could start looking at smaller and smaller gene deletions to study their effect on social behavior."
Two genes in particular, GTF2IRD1 and GTF2I, caught Korenberg's eye. Both encode transcription factors that help regulate the activity of other genes. Although their exact function is unknown, the genes are active in many body tissues and appear to be particularly important in regulating brain and skeletal muscle genes.
In earlier studies, Korenberg and her collaborators linked both GTF2I and GTF2IRD1 to deficits in visual-spatial processing, a hallmark of Williams Syndrome. The researchers are now dissecting the genes' roles even more. "Further parsing the effects of GTF2IRD1 versus GTF2I on spatial construction and social behavior was previously hampered by the small number of cases with fewer than the usual gene deletions and limited cognitive data," explains Korenberg.
To distinguish the roles of the two genes, postdoctoral researcher and study first author Li Dai, Ph.D., combed the genomes of 17 Williams Syndrome patients to identify those who had lost only one GTF2I gene. This allo
|Contact: Phil Sahm|
University of Utah Health Sciences