Types of HPE
This brain malformation can range from mild to severe and is classified into four types:
(1) Alobar (severe) – where the brain is not divided and there are severe abnormalities.
(2) Semi-Lobar (moderate) – where the brain is partially divided and there are some moderate abnormalities; where there are two hemispheres in the rear but not the front of the brain.
(3) Lobar (mild) – where the brain is divided and there are some mild abnormalities.
(3a) Lobar Subtype: Septopreoptic HPE (very mild) – only a small area of the brain is fused and the abnormalities are very mild; children with this subtype usually have good motor function.
(4) Middle Interhemispheric Variant (MIHV) – where the middle of the brain (posterior frontal and parietal lobes) are not well separated.
One of the very best sources of research and clinical diagnosis of HPE is The Carter Centers for Brain Research in Holoprosencephaly and Related Malformations. If you have received a diagnosis of HPE for your child and have not yet contacted the Carter Centers, we strongly encourage you to do so.