PLP1 and Pelizeaus-Merzbacher spectrum disorder: An 11-year-old female patient (DGDP084) with these symptoms was reported to have a de novo Xq22.2 110 kb microdeletion encompassing GLRA4, MORF4L2 and TCEAL. While certain phenotypic features such as cognitive impairment and motor delay overlap with Pelizaeus-Merzbacher disease (PMD) caused by PLP1 mutations at Xq22.2, this gene was apparently not included in the microdeletion and was not dysregulated by a positional effect (Labonne et al., 2016).