GABA and the ornithine delta-aminotransferase gene in vigabatrin-associated visual field defects.
Vigabatrin use in some epilepsy patients has been associated with persistent visual field constriction and retinal dysfunction. The mechanism is unknown, but could be related to vigabatrin, chronic epilepsy, GABA toxicity, or the effect of a metabolite in combination with a predisposing genotype. The aim of this study was to investigate the latter two hypotheses. Levels of brain gamma-aminobutyric acid (GABA) measured by nuclear magnetic resonance spectroscopy were similar in subjects taking vigabatrin who developed visual field constriction and those who did not. We tested whether allelic heterogeneity of the ornithine aminotransferase gene occurs in the affected patients. No clinically significant mutation was detected, although a common intronic polymorphism was identified.
Hisama
F M
FM
Department of Neurology, Yale University School of Medicine, P.O. Box 208018, 333 Cedar St., New Haven, CT, USA. fuki.hisama@yale.edu
Mattson
R H
RH
Lee
H H
HH
Felice
K
K
Petroff
O A
OA
D000927:Anticonvulsants / Q000009:adverse effects*; D001921:Brain / Q000201:enzymology; D004827:Epilepsy / Q000188:drug therapy*; D015698:Genomic Library; D006801:Humans; D009953:Ornithine-Oxo-Acid Transaminase / Q000235:genetics* / Q000378:metabolism; D020888:Vigabatrin / Q000009:adverse effects*; D014786:Vision Disorders / Q000139:chemically induced* / Q000175:diagnosis; D014794:Visual Fields / Q000187:drug effects*; D005680:gamma-Aminobutyric Acid / Q000235:genetics*
D000927:Anticonvulsants; D005680:gamma-Aminobutyric Acid; D009953:Ornithine-Oxo-Acid Transaminase; D020888:Vigabatrin