Clinical phenotype varied dramatically with genotype; Arg207His and Ser647Pro caused a severe childhood-onset, sensory and motor, conduction-slowing neuropathy, whereas Gly552Asp caused a mild, adult-onset, sensory-predominant neuropathy, Thr991Ala an infantile-onset motor neuropathy, and the Met282Lys/Gly286Cys locus a complex, axonal neuropathy.<h4>Conclusions</h4>Heterozygous variants in <i>SLC12A6</i> can cause CMT of all clinical phenotypes, severity and age of onset, depending on the genotype. This evidence concerns the gene SLC12A6 and Infantile onset.