Mediobasal and Mantle Defect of the Prosencephalon: Lobar Holoprosencephaly, Schizencephaly and Diabetes Insipidus

Abstract

An infant is described who had a combination of lobar holoprosencephaly and open-lip schizencephaly. Midline fusion of the basal ganglia was associated with bilateral absence of abundant parts of the brain mantle. Agenesis of the corpus callosum, hypoplasia of the optic nerves and chiasm, absence of the septum pellucidum, posterior pituitary and olfactory bulbs were further components of the malformation. Blindness, intractable seizures, spastic tetra-plegie, somatomental retardation and diabetes insipidus were the main clinical features. A defect in the induction of the mediobasal part of the prosencephalon and failure of cell proliferation can be responsible for this complex malformation. Recent results of homeobox gene research relevant to the development of the prosencephalon are discussed.

Key words

Mediobasal prosencephalic defect - Lobar holoprosencephaly - Schizencephaly - Diabetes insipidus - Homeobox genes