GJC2 and Pelizeaus-Merzbacher spectrum disorder: Pelizaeus-Merzbacher like disease (PMLD) is a hypomyelinating leukodystrophy with very similar clinical manifestation to PMD but caused by autosomal recessive loss-of-function mutations in the gap junction protein connexin 47 (GJC2) gene (Orthmann-Murphy et al., 2007).