The CLCN3 gene provides instructions for making a protein called ClC-3, which helps brain cells communicate and function properly. This protein works like a “gate” that moves charged particles (chloride and protons) in and out of small compartments inside cells. These processes are especially important in the brain for healthy development and ongoing brain activity.
Changes (variants) in the CLCN3 gene can affect how this protein works:
• In some cases, both copies of the gene are changed (inherited from each parent). This usually leads to the body making little or no working protein and causes more severe symptoms.
• In other cases, a change happens “by chance” in just one copy of the gene (not inherited from parents). These can still cause problems, but the severity is more variable.
Research shows that different gene changes may disrupt the protein in different ways. Sometimes the “gate” doesn’t open and close correctly, while in other cases the protein looks normal in the lab but still leads to disease in people. This suggests there may be several ways the gene changes can interfere with brain development.
Animal studies back this up: mice without a working CLCN3 gene develop brain shrinkage, loss of connections between brain regions, and other changes similar to what has been seen in children with the most severe form of the disorder.
CLCN3