This malformation involves defects in midline septation of the brain. Various degrees of severity occur, ranging from alobar to lobar types .
![Image](https://tchescolove.wordpress.com/wp-content/uploads/2012/12/holoprosencephaly-types.gif?w=412)
![Image](https://tchescolove.wordpress.com/wp-content/uploads/2012/12/ra1-1.jpg?w=487)
Affected children are usually diagnosed as neonates because of facial dysmorphism that includes close-set eyes, hypoplastic or absent nose, and microcephaly
![Image](https://tchescolove.wordpress.com/wp-content/uploads/2012/12/holo.jpg?w=487)