Alobar, the most serious form in which the brain has no tendency to separate, is usually associated with severe facial anomalies. Semilobar, in which the brain's hemispheres have a slight tendency to separate, is an intermediate form of the disease. Lobar, in which there is considerable evidence of separate brain hemispheres, is the least severe form. In some cases of lobar holoprosencephaly the patient's brain may be nearly normal. There is no standard course of treatment for holoprosencephaly.
Treatment is symptomatic and supportive.
The prognosis for individuals with the disorder is poor. Most of those who survive show no significant developmental gains. The knowledge gained from these fundamental studies provides the foundation for understanding how this process can go awry and, thus, may eventually give clues to understanding disorders such as holoprosencephaly. The Neurological Disorders. II, 2nd edition, Butterworth-Heinemann, Boston, pp.