Periventricular Heterotopia
Periventricular heterotopia is a condition in which the nerve cells (neurons) do not migrate properly during early development of the fetal brain. People with this condition typically develop recurrent seizures (epilepsy) beginning in mid-adolescence. Intelligence is usually normal, but some people may have mild intellectual disability, including difficulty with reading or spelling. Less common features include microcephaly, developmental delay, recurrent infections, and blood vessel abnormalities. Some cases are caused by changes (mutations) in the FLNA gene and are inherited in an X-linked dominant manner. Other cases are caused by mutations in the ARFGEF2 gene and are inherited in an autosomal recessive manner. Rarely, periventricular heterotopia is associated with a duplication of genetic material on chromosome 5. Treatment is generally focused on managing recurrent seizures with medications.