PLP1 and Pelizeaus-Merzbacher spectrum disorder: Recently, aCGH has been used to detect copy number alterations in the PLP1 region for prenatal diagnosis of Pelizaeus-Merzbacher disease (PMD) (Lee et al. 2005), a rare X-linked dysmyelinating disorder of the central nervous system (Garbern et al. 1999; Inoue, 2005).