686
Prader - Willi syndrome ( PWS ) and Angelman syndrome ( AS ) result from the loss of function of imprinted genes in human chromosome 15q11 - q13 .
 Prader - Willi syndrome, PWS, Angelman syndrome, AS
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Disease 
Text: {0} 
Answer:
 Prader - Willi syndrome, PWS, Angelman syndrome, AS