This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
Angelman syndrome is due to? 
Select and explain. 
A. Mitochondrial inheritance, B. Chimerism, C. Mosaicism, D. Uniparental disomy
D: Uniparental disomy
Answer: D: Uniparental disomy 
Explanation: Angelman syndrome and prader willi syndrome are example of unipareantal disomy.