The critical region is the same as PWS (i.e., 15q11-q13), but parental-of-origin is different; either maternal deletion or paternal uniparental disomy causes Angelman syndrome, because the causative gene, ubiquitin protein ligase E3A (UBE3A), is maternally expressed [67]. The gene discussed is UBE3A; the disease is Angelman syndrome.