What are the genetic changes related to WAGR syndrome ?
WAGR syndrome is caused by a deletion of genetic material on the short (p) arm of chromosome 11. The size of the deletion varies among affected individuals.  The signs and symptoms of WAGR syndrome are related to the loss of multiple genes on the short arm of chromosome 11. WAGR syndrome is often described as a contiguous gene deletion syndrome because it results from the loss of several neighboring genes. The PAX6 and WT1 genes are always deleted in people with the typical signs and symptoms of this disorder. Because changes in the PAX6 gene can affect eye development, researchers think that the loss of the PAX6 gene is responsible for the characteristic eye features of WAGR syndrome. The PAX6 gene may also affect brain development. Wilms tumor and genitourinary abnormalities are often the result of mutations in the WT1 gene, so deletion of the WT1 gene is very likely the cause of these features in WAGR syndrome.  In people with WAGRO syndrome, the chromosome 11 deletion includes an additional gene, BDNF. This gene is active (expressed) in the brain and plays a role in the survival of nerve cells (neurons). The protein produced from the BDNF gene is thought to be involved in the management of eating, drinking, and body weight. Loss of the BDNF gene is likely responsible for childhood-onset obesity in people with WAGRO syndrome. People with WAGRO syndrome may be at greater risk of neurological problems such as intellectual disability and autism than those with WAGR syndrome. It is unclear whether this increased risk is due to the loss of the BDNF gene or other nearby genes.  Research is ongoing to identify additional genes deleted in people with WAGR syndrome and to determine how their loss leads to the other features of the disorder.