As demonstrated by Verheij et al. [43] and Fernández et al. [44], SOX10 variants have been shown to be associated with a more severe phenotype, termed PCWH (peripheral demyelinating neuropathy, central demyelinating leukodystrophy, Waardenburg syndrome, and Hirschsprung’s disease), further supporting the genetic and phenotypic heterogeneity. The gene discussed is SOX10; the disease is Waardenburg syndrome.