Hello and thanks for writing. I can understand your concern and would try to help you in the best possible way. Selective Mutism is a complex childhood anxiety disorder characterized by a child s inability to speak and communicate effectively in select social settings, such as school. These children are able to speak and communicate in settings where they are comfortable, secure, and relaxed. It is a problem of language and speech and is treatable in most of the children. As a concerned parent your role i this becomes critical. Your child would require a few sessions with a speech or language therapist. I suggest you consult your GP or family doctor who would rule out any organic cause for it and also guide you to the nearest therapy centre.