Cheshire P, Bertram K, Ling H, O'Sullivan SS, Halliday G, McLean C, Bras J, Foltynie T, Storey E, Williams DR. Influence of single nucleotide polymorphisms in COMT, MAO-A and BDNF genes on dyskinesias and levodopa use in Parkinson's disease.
NEURODEGENER DIS 2013;
13:24-8. [PMID:
24008922 PMCID:
PMC4194629 DOI:
10.1159/000351097]
[Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 03/29/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND
Clinical heterogeneity in the development of levodopa-induced dyskinesias (LID) suggests endogenous factors play a significant role in determining their overall prevalence.
OBJECTIVE
We hypothesised that single nucleotide polymorphisms (SNPs) in specific genes may result in a clinical phenotype conducive to an increased risk of LID.
METHODS
We examined the influence of SNPs in the catechol-O-methyltransferase (COMT), monoamine oxidase A (MAO-A) and brain-derived neurotrophic factor (BDNF) genes on LID in a cohort of 285 pathologically confirmed Parkinson's disease patients, using data from their complete disease course.
RESULTS
Dyskinetic patients demonstrated younger age at disease onset (60.3 vs. 66.4 years, p < 0.0001), a longer disease duration (17.0 vs. 12.0 years, p < 0.0001) and a higher maximum daily levodopa equivalent dose (LED; 926.7 vs. 617.1 mg/day, p < 0.0001) than patients without dyskinesias. No individual SNP was found to influence prevalence or time to onset of dyskinesias, including after adjustment for known risk factors. We observed that patients carrying alleles conferring both high COMT activity and increased MAO-A mRNA expression received significantly higher maximum and mean daily LEDs than those with low enzyme activity/mRNA expression (max LED: 835 ± 445 vs. 508 ± 316 mg; p = 0.0056, mean LED: 601 ± 335 vs. 398 ± 260 mg; p = 0.025).
CONCLUSIONS
Individual SNPs in BDNF, COMT and MAO-A genes did not influence prevalence or time to onset of dyskinesias in this cohort. The possibility that combined COMT and MAO-A genotype is a significant factor in determining an individual's lifetime levodopa exposure warrants further investigation.
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