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Abstract Details

Blood Mitochondrial DNA Copy Number Is Associated with Motor Symptoms and Dementia in Parkinson’s Disease
Movement Disorders
S26 - Movement Disorders: Basic Science (4:54 PM-5:06 PM)
Mitochondria dysfunction affects PD through the accumulation of pathogenic alpha-synuclein, oxidative stress, impaired autophagy, and neuroinflammation. Previous studies showed that blood mtDNA-CN was lower in patients with PD and Alzheimer’s disease than in healthy controls. However, little is known about the correlation between mtDNA-CN and the severity of motor symptoms or dementia in PD.
We aimed to investigate the association of mitochondrial DNA copy number (mtDNA-CN) obtained from peripheral blood cells with the severity of motor symptoms or cognitive impairment in PD.

We estimated mtDNA-CN in 405 patients with PD and 200 healthy individuals, using whole genome sequencing for blood samples. We defined mtDNA-CN level as [ 2*mitochondrial DNA coverage/nuclear DNA coverage]. Pearson correlation analysis was performed to find the association between mtDNA-CN and motor severity (UPDRS II+III at medication off state) and Hoehn and Yahr (H&Y) stage.  In a subgroup of PD patients who were diagnosed with PD within the last three years, Cox regression analysis was performed to assess the progression of motor symptoms from H&Y stage 2.5 to 3, and the progression to dementia according to mtDNA-CN, after adjusting for age and sex.

The mtDNA-CN level was significantly lower in patients with PD than in healthy controls (median 179.1 vs. 211.6, P=1.1x10-5). The mtDNA-CN level was negatively correlated with motor severity of PD (r=-0.20; P=0.008). Among 210 patients with early PD within three years from diagnosis, Cox regression analysis showed that patients in the lowest tertile of mtDNA-CN were associated with higher risk of dementia compared to the highest tertile (HR=4.10, CI 1.12−15.26, P=0.03) after adjusting for sex and age. However, mtDNA-CN was not associated with motor progression.

Our study provides significant association of blood mtDNA-CN with PD and cognitive outcome in PD.

Sun Ju Chung (Neurology, Asan Medical Center)
Dr. Chung has nothing to disclose.
Sungyang Jo (Asan Medical Center) Dr. Jo has nothing to disclose.
No disclosure on file
No disclosure on file
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