Periventricular heterotopia.
Periventricular heterotopia (PH) is clinically diagnosed on the basis of the radiographic characteristics of heterotopic nodules composed of disorganized neurons along the lateral ventricles of the brain. Epilepsy is the main presenting symptom of patients with PH. Behaviorally, patients generally are of normal intelligence, although there have been associated findings of learning disabilities, namely, dyslexia. Two genes responsible for PH have been identified: FilaminA, which encodes for the protein filamin A, and ARFGEF2, which encodes for the vesical transport-regulating protein ARFGEF2. The much more common X-linked dominant form of this disorder is due to filamin A, affects females, and is typically lethal in males. A much rarer autosomal recessive form due to ARFGEF2 mutations leads to microcephaly and developmental delay in addition to PH. Cell motility, adhesion defects, and weakening along the neuroepithelial lining may result from defects in these genes during cortical development and contribute to PH, but the mechanisms are not clear yet. Treatment of PH is largely symptomatic, following basic principles for epilepsy management and genetic counseling.
Division of Neurogenetics and Howard Hughes Medical Institute, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA.
Jie
J
Lu
Volney
V
Sheen
D000818:Animals; D001927:Brain Diseases / Q000150:complications / Q000235:genetics / Q000473:pathology* / Q000628:therapy; D002318:Cardiovascular Diseases / Q000209:etiology; D003285:Contractile Proteins / Q000235:genetics; D004410:Dyslexia / Q000209:etiology; D004535:Ehlers-Danlos Syndrome / Q000209:etiology; D004827:Epilepsy / Q000209:etiology*; D064448:Filamins; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics; D006801:Humans; D020547:Lateral Ventricles / Q000002:abnormalities* / Q000000981:diagnostic imaging; D008840:Microfilament Proteins / Q000235:genetics; D009474:Neurons / Q000473:pathology*; D011859:Radiography; D014960:X Chromosome
C119088:ARFGEF2 protein, human; D003285:Contractile Proteins; D064448:Filamins; D020662:Guanine Nucleotide Exchange Factors; D008840:Microfilament Proteins