Dup (3) (pter-p22.1): A rare chromosomal disorder characterized by various anomalies. The listed symptoms are those observed in one reported case. The manifestations linked to most genetic defects are often variable to some degree.
Lennox-Gastaut Syndrome: A form of epilepsy that occurs mostly in preschool-aged children and is characterized mainly by absences.
Lissencephaly: A very rare disorder characterized by abnormal brain formation so that the brain surface appears smooth rather than convoluted.
Lissencephaly 3: A rare brain malformation where the surface of the brain is smoother than normal. The brain abnormality causes symptoms such as mental retardation and seizures. The severity of the disorder is variable and is caused by a genetic defect on chromosome 12q12-q14.
Lissencephaly type 1, due to LIS 1 anomalies: A rare brain malformation where the surface of the brain is smoother than normal. Type 1 is caused by a defect on the LIS1 gene on chromosome 17p13.3. The severity of the symptoms are variable depending on the severity of the brain abnormality. Miller-Dieker syndrome is a subtype of this condition.
Miller-Dieker syndrome: A rare genetic disorder characterized by a smooth brain surface. The condition occurs because of deletion of genetic material from the short arm of chromosome 17 ath a particular location (17p13.3).