A male infant with trisomy 21 simultaneously showed clinical features of hypomelanosis of Ito and hemimegalencephaly, with related intractable epileptic seizures. The epileptic seizures were refractory to conventional antiepileptic drugs and persisted until the patient underwent functional hemispherotomy. It is well known that patients with hypomelanosis of Ito may also have cortical dysplasia and hemimegalencephaly and that approximately half of these patients have chromosomal abnormalities. However, to our knowledge, there is no previous report of a patient with trisomy 21 associated with hemimegalencephaly. Here, we describe a rare case of coexisting trisomy 21 and hypomelanosis of Ito, associated with hemimegalencephaly.
JonesKL. Down syndrome. In: HummelTDavisKJ, eds. SMITH’S Recognizable Patterns of Human Malformation. 6th ed. Philadelphia, PA: Elsevier; 2006:7–12.
3.
Goldberg-SternHStrawsburgRHPattersonB. Seizure frequency and characteristics in children with Down syndrome. Brain Dev. 2001;23:375–378.
4.
TatsunoMHayashiMIwamotoH. Epilepsy in childhood Down syndrome. Brain Dev. 1984;6:37–44.
5.
Pascual-CastroviejoIRocheCMartinez-BermejoA. Hypomelanosis of Ito. A study of 76 infantile cases. Brain Dev. 1998;20:36–43.
6.
Flores-SarnatL.Hemimegalencephaly. Part 1. Genetic, clinical, and imaging aspects. J Child Neurol. 2002;17:373–384.
7.
TagawaTFutagiYAraiH. Hypomelanosis of Ito associated with hemimegalencephaly: a clinicopathological study. Pediatr Neurol. 1997;17:180–184.
8.
BoerKTroostDSplietWGM. A neuropathological study of two autopsy cases of syndromic hemimegalencephaly. Neuropathol Appl Neurobiol. 2007;33:455–470.
9.
AssogbaKFerlazzoEStrianoP. Heterogeneous seizure manifestations in hypomelanosis of Ito: report of four new cases and review of the literature. Neurol Sci. 2010;31:9–16.
10.
IypeMIypeTGeethaSRetnakumarJ. Hypomelanosis of Ito with cerebral malformation. Indian J Pediatr. 2007;74:1044–1045.
11.
RuggieriMPavoneL. Hypomelanosis of Ito: clinical syndrome or just phenotype?J Child Neurol. 2000;15:635–644.
12.
SchwartzMFJrEaterlyNBFretzinDF. Hypomelanosis of Ito (incontinentia pigmenti achromians): a neurocutaneous syndrome. J Pediatr. 1977;90:236–240.
13.
ArdingerHHBellWE. Hypomelanosis of Ito. Wood’s light and magnetic resonance imaging as diagnostic measures. Arch Neurol. 1986;43:848–850.
14.
RuggieriMRogginiMSpaliceA. Pigmentary mosaicism, subcortical band heterotopia, and brain cystic lesions. Pediatr Neurol. 2009;40:383–386.
15.
BarankinBGuentherL. Dermatological manifestations of Down’s syndrome. J Cutan Med Surg. 2001;5:289–293.
16.
Di RoccoCBattagliaDPietriniD. Hemimegalencephaly: clinical implications and surgical treatment. Child Nerv Syst. 2006;22:852–866.
17.
DevlinAMCrossJHHarknessW. Clinical outcomes of hemispherectomy for epilepsy in childhood and adolescence. Brain. 2003;126:556–566.
18.
SasakiMHashimotoTFurushimaW. Clinical aspects of hemimegalencephaly by means of a nationwide survey. J Child Neurol. 2005;20:337–341.
19.
ChapmanKCardenasJF. Hemimegalencephaly in a patient with a neurocutaneous syndrome. Semin Pediatr Neurol. 2008;15:190–193.
20.
GuptaSShahSMcgawA. Trisomy 2 mosaicism in hypomelanosis of Ito. Am J Med Genet A. 2007;143:2466–2468.
21.
MirzaaGAshwalSDobynsWB. Disorders of brain size. In: SwaimanKFAshwalSFerrieroDMSchorNF, eds. Pediatric Neurology Principles and Practice. 4th ed. Philadelphia, PA: Mosby Elsevier; 2012:173–201.
22.
LoddenkemperTAlexopoulosAVKotagalP. Epilepsy surgery in epidermal nevus syndrome variant with hemimegalencephaly and intractable seizures. J Neurol. 2008;255:1829–1831.
23.
ChuganiHTAsanoESoodS.Infantile spasms: Who are the ideal surgical candidates?Epilepsia. 2010;51(suppl 1):94–96.
