Since the pUPD6 in the PMD specimen in this case was isolated, which meant that there was normal methylation of ICR2 and a normal biparental genotype except for chromosome 6, hypomethylation of PLAGL1:alt-TSS-DMR at 6q24.2 was a possible etiology for the PMD. This evidence concerns the gene PLAGL1 and Pelizeaus-Merzbacher spectrum disorder.