Lissencephaly syndrome, Norman-Roberts type is a rare condition that affects brain development. It is characterized by a smooth brain surface due to lissencephaly type I, which means there are fewer or no folds in the brain. Additionally, people with this condition have distinctive craniofacial features including severe microcephaly (a very small head), a low sloping forehead, a broad and prominent nasal bridge, and widely set eyes. The condition is further associated with postnatal growth retardation, meaning growth after birth is slower than expected. This combination of brain development differences and unique facial features underlies the challenges faced by people with Norman-Roberts syndrome.

People with Norman-Roberts syndrome often show signs of lissencephaly, which means the brain has an abnormally smooth surface. They usually present with severe microcephaly and noticeable facial differences, such as a low sloping forehead, a broad and prominent nasal bridge, and eyes that are set wider apart than usual. Growth after birth may also be slower than normal.

This syndrome is linked to genetic changes. The gene implicated in this condition is RELN. Changes in this gene can affect how the brain forms and develops, leading to the features seen in Norman-Roberts syndrome. Associated genes include RELN.