Source:http://linkedlifedata.com/resource/umls/id/C0236826
NCI: A disorder characterized by an impairment in the development of an individual's expressive language which is in contrast to his/her nonverbal intellect and receptive language development. The impairment may be acquired (i.e., due to a brain lesion or head trauma) or developmental (i.e., no known neurological insult).