SLC12A6 and peripheral neuropathy: However, global knockout of Kcc3 in the mouse partially phenocopies the human KCC3 loss‐of‐function disease, Andermann syndrome, characterized by severe peripheral neuropathy with variable agenesis of the corpus callosum (Boettger et al., 2003; Ding & Delpire, 2014; Howard et al., 2002).