A defect of development of the brain characterized by absence of the telencephalon (embryonic structure from which the mature cerebrum develops).
Comment:
Atelencephaly can be differentiated from anencephaly by the presence of a\nskull and an intact scalp. Aprosencephaly is characterized by absence of the telencephalon and diencephalon (embryonic structure from which the thalamus develops). Atelencephaly is generally fatal.