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|LETTER TO EDITOR
|Year : 2016 | Volume
| Issue : 2 | Page : 327-328
Epilepsy with PCDH19 mutation masquerading as benign partial epilepsy in infancy
Department of Pediatrics, Division of Child Neurology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
|Date of Web Publication||3-Mar-2016|
Department of Pediatrics, Division of Child Neurology, University of Arkansas for Medical Sciences,
Little Rock, Arkansas,
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Samanta D. Epilepsy with PCDH19 mutation masquerading as benign partial epilepsy in infancy. Neurol India 2016;64:327-8
An 8-month-old white female infant was admitted to the hospital with recent-onset seizures. She was in her usual health when she started having clusters of seizures. The seizure semiology consisted of staring, eyelid fluttering, stiffening, twitching and jerking of the extremities, and oxygen desaturation lasting for a few seconds to up to 3 minutes. In the post-ictal phase, she would remain drowsy for approximately 1 hour. The family denied any history of fever, constitutional symptoms of infection, head injury, or accidental exposure to any medicine. She was given intravenous lorazepam, levetiracetam, and fosphenytoin in the emergency department to stop her frequently occurring, recurrent seizures. However, these medications were unsuccessful to stop her seizures for more than a few hours. She was, subsequently, admitted to the inpatient unit, where over the next 5 days, she experienced 3–12 daily episodes of seizures. She received levetiracetam, phenytoin, phenobarbital, lacosamide, oral prednisolone (in tapering doses), intravenous immunoglobulin, and pyridoxine. From the day 6 of admission, she became seizure-free and was discharged with maintenance dose of levetiracetam and lacosamide. Her video-EEG showed bicentroparietal-onset electrographic seizures manifested as clonic body jerking that occurred more on the left when compared to the right side; a few episodes were associated with oxygen desaturation. Magnetic resonance imaging (MRI) of the brain, with and without contrast, and serum amino acid, urine organic acid, lactate, pyruvate and carnitine levels, as well as the cerebrospinal fluid (CSF) neurotransmitter assay were normal. After discharge, the patient was followed up in the neurology clinic. She remained seizure free for 2 years; the antiepileptic drugs were weaned off subsequently. Her routine electroencephalogram (EEG) and her development remained normal. She was characterized clinically as having the syndrome of benign partial epilepsy in infancy (BPEI). Subsequently, however, she again started having repeated clusters of seizures requiring frequent visits to the emergency department and admission to the hospital. The previously performed laboratory tests were repeated and remained unremarkable, but a sequencing and deletion/duplication analysis of 18 common genes associated with epilepsy revealed a novel missense mutation in the PCDH19 gene (cDNA-c. 344 T>A, Variant p Ile 115 Lys).
BPEI is characterized by seizure clusters, the onset of seizures during the first year of life, normal developmental milestones, no known etiology, normal neuroimaging, normal interictal EEG, and an excellent response to drug treatment. A positive family history can be helpful but may be found to be absent in many cases. Evaluation at the age of 2 years can diagnose more than 90% of the patients with BPEI if there is no seizure recurrence. The persistence of normal psychomotor development at the age of 5 years helps in a more definitive diagnosis of this syndrome. Autosomal-dominant transmission is possible, but no particular gene has been linked with this syndrome. In most of the patients with BPEI, epilepsy is easily controllable. They, therefore, have an excellent prognosis and do not usually undergo a genetic evaluation. Following the widespread and routine genetic testing in both research and clinical settings, this epilepsy syndrome may turn out to be a heterogeneous entity.
Mutations in the PCDH19 gene typically cause early infantile epileptic encephalopathy, often characterized as epilepsy and mental retardation limited to female individuals (EFMR). However, the clinical features of this disease are highly variable. The most common presenting feature is repeated clusters of focal seizures provoked by fever and usually difficult to control in early childhood. This manifestation is quite similar to that occurring in Dravet syndrome. Although normal intellectual development has been reported, prominent intellectual impairment, developmental regression, and behavioral abnormality, including autistic traits, are common. This mutation is inherited in an unusual X-linked manner: heterozygous female individuals have epilepsy, while male mutation carriers are asymptomatic. There is scarcity of literature on the availability of suitable agents that may help in promptly suppressing the seizure clusters in this epileptic encephalopathy.
This interesting case highlights two points: The importance of continuous vigilance of cases diagnosed with BPEI until the age of 5 years; and, the presence of variable phenotypes associated with the manifestations of the PCDH19 mutation. Further reporting of such cases may facilitate an early diagnosis and better management of patients with PCDH19-related epilepsy.
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Conflicts of interest
There are no conflicts of interest.
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Okumura A, Hayakawa F, Kato T, Kuno K, Negoro T, Watanabe K. Early recognition of benign partial epilepsy in infancy. Epilepsia 2000;41:714-7.
Higurashi N, Nakamura M, Sugai M, Ohfu M, Sakauchi M, Sugawara Y, et al
. PCDH19-related female-limited epilepsy: Further details regarding early clinical features and therapeutic efficacy. Epilepsy Res 2013;106:191-9.