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Updated: Aug 29, 2026

Induction and Assessment of Levodopa-induced Dyskinesias in a Rat Model of Parkinson's Disease
Published on: October 14, 2021
Association between catechol-O-methyltransferase gene polymorphisms and wearing-off and dyskinesia in Parkinson's
M Watanabe1, S Harada, T Nakamura
1Department of Neurology, Institute of Clinical Medicine, University of Tsukuba, Tsukuba, Japan. masa.wat@igaku.md.tsukuba.ac.jp
Abstract:
Catechol-O-methyltransferase (COMT) is an enzyme that inactivates catecholamines, including levodopa. An amino acid change (Val-108-Met) in the COMT protein has been found to result in a change from high to low enzyme activity. In the present study, we genotyped 121 Japanese patients with Parkinson's disease (PD) and 100 controls. Comparison of the allele frequencies revealed that homozygosity for the low-activity allele was significantly more common among PD patients than the controls (p = 0.047, odds ratio = 3.23). In addition, homozygosity for the low-activity allele was overrepresented in PD patients that exhibited the 'wearing-off' phenomenon (p = 0.045, odds ratio = 3.82) or dyskinesia (p = 0.030, odds ratio = 4.80) compared with controls, although these differences were not significant after Bonferroni's correction. Our results may help understand the mechanism that cause complications of levodopa therapy in PD patients.
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