Neurologic orphan diseases: Emerging innovations and role for genetic treatments

Figure 4 Chromosome 15 (15q11-13) abnormality in patients with Prader-Willi syndrome and Angelman syndrome. In patients with Prader-Willi syndrome (PWS) and Angelman syndrome (AS), the imprinted gene abnormality is the 15q11-q13 region of chromosome 15. Although the abnormality is in the same region, the difference in disease and phenotype depends on the parental contribution. In PWS, the disease results due to loss of paternal gene expression. In AS, the disease results due to loss of maternal gene expression. PWS: Prader-Willi syndrome; AS: Angelman syndrome.