While two out of 75 tested patients with Kuf's disease, which features phenotypes in common with those found in ClC-6 knock-out mice (Berkovic et al., 1988), were heterozygous for CLCN6 missense variants, no further evidence for ClC-6 dysfunction underlying this disease was found (Poët et al., 2006). This evidence concerns the gene CLCN6 and adult neuronal ceroid lipofuscinosis.