985
Mounting evidence suggests a possible role for gamma - aminobutyric acid ( GABA ) in the neuropathophysiology of autism spectrum disorders ( ASD ) , but the extent of this impairment is unclear .
 Chemical: gamma - aminobutyric acid; Chemical: GABA
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: gamma - aminobutyric acid; Chemical: GABA