X-linked nodular periventricular heterotopia is a migratory neuronal disorder characterized by the presence of noncalcified nodules of ectopic neurons located along the surface of the lateral ventricles. Affected individuals are predominantly heterozygous females, resulting lethal in males. Affected women begin to show symptoms at a mean age of 14-15 years; intelligence ranges from normal to borderline. The risk of heart attack and other vascular problems are increased.X-linked nodular periventricular heterotopia is caused by mutations in the FLNA gene, inheriting in an X-linked dominant manner, being lethal in most prenatal and newborn males; resulting in the majority of affected individuals being female. Approximately 50% of affected women inherit the mutation from their mother, with the other 50% having de novo mutations.