1139
CASE REPORT: A six-year-old boy with transfusion-dependent beta-thalassaemia developed a unilateral hearing loss shortly after commencing desferrioxamine therapy.
 adverse event: developed 
Please tell me event type and its trigger word from given type options. Output format is "type: trigger".  Option: adverse event, potential therapeutic event 
Text: {0} 
Answer:
 adverse event: developed 