Question: What is (are) Absence of the Septum Pellucidum ?
Answer: The septum pellucidum (SP) is a thin membrane located at the midline of the brain between the two cerebral hemispheres, or halves of the brain.. It is connected to the corpus callosum -- a collection of nerve fibers that connect the cerebral hemispherers. This rare abnormality accompanies various malformations of the brain that affect intelligence, behavior, and the neurodevelopmental process, and seizures may occur. Children who are born without this membrane and also have other abnormalities--pituitary deficiencies and abnormal development of the optic disk--have a disorder known as septo-optic dysplasia. More information about this condition can be located at the NINDS Septo-Optic Dysplasia Information Page.
Source: NINDS

Question: What are the treatments for Absence of the Septum Pellucidum ?
Answer: Absence of the SP alone is not a disorder but is instead a characteristic noted in children with septo-optic dysplasia or other developmental anomalies.
Source: NINDS