Abstract |
A cause of antiepileptic medication resistant seizures presenting in neonates and young infants is pyridoxine-dependent epilepsy (PDE), an organic aciduria, which is due to recessive mutations in the ALDH7A1 gene, resulting in deficiency of antiquitin. Since the discovery of molecular basis of this disorder, a few patients have been reported with a similar clinical phenotype but without evidence of antiqutin dysfunction. We report on a patient who had carried a clinical diagnosis of PDE for 7 years, but who was than shown to have normal ALDH7A1 sequencing and the absence of biomarkers characteristic of this familial epilepsy. Array comparative genomic hybridization (CGH) demonstrated a 1.5-Mb terminal deletion of the long arm of chromosome 20, which included deletion of the KCNQ2 and CHRNA4 genes, both of which have been associated with specific epilepsy syndromes. We suggest that this boy's neonatal epilepsy and neurodevelopmental disabilities are secondary to this deletion and that his clinical response to pyridoxine was coincidental. This patient's history emphasizes the utility of array CGH in the evaluation of children with epilepsy of unknown etiology.
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Authors | Heather C Mefford, Joseph Cook, Sidney M Gospe Jr |
Journal | American journal of medical genetics. Part A
(Am J Med Genet A)
Vol. 158A
Issue 12
Pg. 3190-5
(Dec 2012)
ISSN: 1552-4833 [Electronic] United States |
PMID | 23166088
(Publication Type: Case Reports, Journal Article)
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Copyright | Copyright © 2012 Wiley Periodicals, Inc. |
Chemical References |
- KCNQ2 Potassium Channel
- KCNQ2 protein, human
- Receptors, Nicotinic
- nicotinic acetylcholine receptor alpha4 subunit
- ALDH7A1 protein, human
- Aldehyde Dehydrogenase
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Topics |
- Aldehyde Dehydrogenase
(genetics)
- Child
- Chromosomes, Human, 19-20
- Diagnosis, Differential
- Epilepsy
(diagnosis, genetics)
- Humans
- KCNQ2 Potassium Channel
(genetics)
- Male
- Mutation
- Receptors, Nicotinic
(genetics)
- Sequence Deletion
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