chromodomain helicase DNA binding protein 7
The CHD7 gene provides instructions for making a protein called chromodomain helicase DNA binding protein 7. The CHD7 protein belongs to a family of proteins that are thought to play a role in the organization of chromatin. Chromatin is the complex of DNA and protein that packages DNA into chromosomes. The CHD7 protein most likely regulates gene activity (expression) by a process known as chromatin remodeling. The structure of chromatin can be changed (remodeled) to alter how tightly DNA is packaged. When DNA is tightly packed, gene expression is lower than when DNA is loosely packed. Studies have shown that the CHD7 gene is expressed in many fetal tissues, including the eye, inner ear, and brain cells that process smell (olfactory bulb).
Mutations in the CHD7 gene are found in approximately 60 percent to 65 percent of individuals with CHARGE syndrome. At least 150 mutations have been found throughout the gene. Most mutations lead to the production of an abnormally short, nonfunctional CHD7 protein, which presumably disrupts chromatin remodeling and the regulation of gene expression. Changes in gene expression during embryonic development likely cause the signs and symptoms of CHARGE syndrome.