CLC and nervous system disorder: Mutations such as ClC-3I607T, ClC-4I549N (equivalent to G554 in ClC-6), ClC-4V550L, and ClC-4A555V, located in the P/Q linker and helix Q; ClC-3T570I, located in helix O, ClC-4P310S, ClC-4V317F, and ClC-4V317I, located in helix I and I/J loop cause abnormal inward currents at acidic extracellular pH and are associated with neurological disease (70, 71).