GBA mutations are associated with Rapid eye movement sleep behavior disorder

Rapid eye movement sleep behavior disorder and GBA mutations are both associated with Parkinson’s disease. The GBA gene was sequenced in idiopathic rapid eye movement sleep behavior disorder patients (n = 265), and compared to controls (n = 2240). Rapid eye movement sleep behavior disorder questionnaire was performed in an independent Parkinson’s disease cohort (n = 120). GBA mutations carriers had an OR of 6.24 (10.2% in patients vs. 1.8% in controls, P < 0.0001) for rapid eye movement sleep behavior disorder, and among Parkinson’s disease patients, the OR for mutation carriers to have probable rapid eye movement sleep behavior disorder was 3.13 (P = 0.039). These results demonstrate that rapid eye movement sleep behavior disorder is associated with GBA mutations, and that combining genetic and prodromal data may assist in identifying individuals susceptible to Parkinson’s disease

The role of the melanoma gene MC1R in Parkinson disease and REM sleep behavior disorder

The MC1R gene, suggested to be involved in Parkinson disease (PD) and melanoma, was sequenced in PD patients (n=539) and controls (n=265) from New-York, and PD patients (n=551), rapid eye movement sleep behavior disorder (RBD) patients (n=351) and controls (n=956) of European ancestry. Sixty-eight MC1R variants were identified, including 7 common variants with frequency>0.01. None of the common variants was associated with PD or RBD in the different regression models. In a meta-analysis with fixed-effect model, the p.R160W variant was associated with an increased risk for PD (OR=1.22, 95%CI 1.02-1.47, p=0.03) but with significant heterogeneity (p=0.048). Removing one study that introduced the heterogeneity resulted in nonsignificant association (OR=1.11, 95%CI 0.92-1.35, p=0.27, heterogeneity p=0.57). Rare variants had similar frequencies in patients and controls (10.54% and 10.15%, respectively, p=0.75), and no cumulative effect of carrying more than one MC1R variant was found. The current study does not support a role for the MC1R p.R160W and other variants in susceptibility for PD or RBD

Progressive development of augmentation during long-term treatment with levodopa in restless legs syndrome: results of a prospective multi-center study

The European Restless Legs Syndrome (RLS) Study Group performed the first multi-center, long-term study systematically evaluating RLS augmentation under levodopa treatment. This prospective, open-label 6-month study was conducted in six European countries and included 65 patients (85% treatment naive) with idiopathic RLS. Levodopa was flexibly up-titrated to a maximum dose of 600 mg/day. Presence of augmentation was diagnosed independently by two international experts using established criteria. In addition to the augmentation severity rating scale (ASRS), changes in RLS severity (International RLS severity rating scale (IRLS), clinical global impression (CGI)) were analyzed. Sixty patients provided evaluable data, 35 completed the trial and 25 dropped out. Augmentation occurred in 60% (36/60) of patients, causing 11.7% (7/60) to drop out. Median time to occurrence of augmentation was 71 days. The mean maximum dose of levodopa was 311 mg/day (SD: 105). Patients with augmentation compared to those without were significantly more likely to be on higher doses of levodopa (≥300 mg, 83 vs. 54%, P = 0.03) and to show less improvement of symptom severity (IRLS, P = 0.039). Augmentation was common with levodopa, but could be tolerated by most patients during this 6-month trial. Patients should be followed over longer periods to determine if dropout rates increase with time

Common variants in P2RY11 are associated with narcolepsy.

Growing evidence supports the hypothesis that narcolepsy with cataplexy is an autoimmune disease. We here report genome-wide association analyses for narcolepsy with replication and fine mapping across three ethnic groups (3,406 individuals of European ancestry, 2,414 Asians and 302 African Americans). We identify a SNP in the 3' untranslated region of P2RY11, the purinergic receptor subtype P2Y₁₁ gene, which is associated with narcolepsy (rs2305795, combined P = 6.1 × 10⁻¹⁰, odds ratio = 1.28, 95% CI 1.19-1.39, n = 5689). The disease-associated allele is correlated with reduced expression of P2RY11 in CD8(+) T lymphocytes (339% reduced, P = 0.003) and natural killer (NK) cells (P = 0.031), but not in other peripheral blood mononuclear cell types. The low expression variant is also associated with reduced P2RY11-mediated resistance to ATP-induced cell death in T lymphocytes (P = 0.0007) and natural killer cells (P = 0.001). These results identify P2RY11 as an important regulator of immune-cell survival, with possible implications in narcolepsy and other autoimmune diseases.journal articleresearch support, n.i.h., extramuralresearch support, non-u.s. gov'tresearch support, u.s. gov't, p.h.s.2011 Jan2010 12 19importedErratum in : Nat Genet. 2011 Oct;43(10):1040

The role of the melanoma gene MC1R in Parkinson disease and REM sleep behavior disorder

The MC1R gene, suggested to be involved in Parkinson disease (PD) and melanoma, was sequenced in PD patients (n = 539) and controls (n = 265) from New York, and PD patients (n = 551), rapid eye movement sleep behavior disorder (RBD) patients (n = 351), and controls (n = 956) of European ancestry. Sixty-eight MC1R variants were identified, including 7 common variants with frequency > 0.01. None of the common variants was associated with PD or RBD in the different regression models. In a meta-analysis with fixed-effect model, the p.R160W variant was associated with an increased risk for PD (odds ratio = 1.22, 95% confidence interval = 1.02–1.47, p = 0.03) but with significant heterogeneity (p = 0.048). Removing one study that introduced the heterogeneity resulted in nonsignificant association (odds ratio = 1.11, 95% confidence interval, 0.92–1.35, p = 0.27, heterogeneity p = 0.57). Rare variants had similar frequencies in patients and controls (10.54% and 10.15%, respectively, p = 0.75), and no cumulative effect of carrying more than one MC1R variant was found. The present study does not support a role for the MC1R p.R160W and other variants in susceptibility for PD or RBD

The role of the melanoma gene MC1R in Parkinson disease and REM sleep behavior disorder

The MC1R gene, suggested to be involved in Parkinson disease (PD) and melanoma, was sequenced in PD patients (n = 539) and controls (n = 265) from New York, and PD patients (n = 551), rapid eye movement sleep behavior disorder (RBD) patients (n = 351), and controls (n = 956) of European ancestry. Sixty-eight MC1R variants were identified, including 7 common variants with frequency > 0.01. None of the common variants was associated with PD or RBD in the different regression models. In a meta-analysis with fixed-effect model, the p.R160W variant was associated with an increased risk for PD (odds ratio = 1.22, 95% confidence interval = 1.02–1.47, p = 0.03) but with significant heterogeneity (p = 0.048). Removing one study that introduced the heterogeneity resulted in nonsignificant association (odds ratio = 1.11, 95% confidence interval, 0.92–1.35, p = 0.27, heterogeneity p = 0.57). Rare variants had similar frequencies in patients and controls (10.54% and 10.15%, respectively, p = 0.75), and no cumulative effect of carrying more than one MC1R variant was found. The present study does not support a role for the MC1R p.R160W and other variants in susceptibility for PD or RBD

Review of quality of life instruments for the restless legs syndrome/Willis-Ekbom Disease (RLS/WED):critique and recommendations

OBJECTIVES: Over the last decade therapeutic, pathogenetic, epidemiological and genetic research in restless legs syndrome/Willis-Ekbom Disease (RLS/WED) has required the development of specific quality of life scales and sleep scales. A Movement Disorder Society Task Force formally evaluated the quality of these scales. METHODS: A literature search retrieved 5 quality of life instruments specific to RLS. As per MDS protocol, each scale was evaluated by 3 criteria which included (a) use in RLS, (b) use by research or clinical groups other than the group that developed the scale, and (c) formal validation and adequate clinimetric properties. Scales were categorized as “Recommended” when all 3 criteria were met, “Suggested” when used for RLS but only one of the other criteria was met, and “Listed” when used in RLS but there was absence of the other two criteria. Details regarding the development, use and clinimetric properties of each instrument are summarized along with the recommendations of the Task Force. RESULTS AND CONCLUSION: The Restless Legs Syndrome Quality of Life Scale-Abetz (RLS-QOL-Abetz) is the only scale designated as Recommended for use in cross-sectional assessments and treatment-related changes in RLS quality of life. Daily diaries hold future promise for the evaluation of RLS symptoms without the need for retrospective recall. An important need is the development of pediatric RLS quality of life instruments. CITATION: Walters AS, Frauscher B, Allen R, Benes H, Chaudhuri KR, Garcia-Borreguero D, Lee HB, Picchietti DL, Trenkwalder C, Martinez-Martin P, Stebbins GT, Schrag A; MDS Committee on Rating Scales. Review of quality of life instruments for the restless legs syndrome/Willis-Ekbom Disease (RLS/WED): critique and recommendations. J Clin Sleep Med 2014;10(12):1351-1357

A single-question screen for rapid eye movement sleep behavior disorder:a multicenter validation study

BACKGROUND: Idiopathic REM sleep behavior disorder (RBD) is a parasomnia that is an important risk factor for PD and Lewy body dementia. Its prevalence is unknown. One barrier to determining prevalence is that current screening tools are too long for large-scale epidemiologic surveys. Therefore, we designed the REM Sleep Behavior Disorder Single-Question Screen (RBD1Q), a screening question for dream enactment with a simple yes/no response. METHODS: Four hundred and eighty-four sleep-clinic– based participants (242 idiopathic RBD patients and 242 controls) completed the screen during a multicenter case-control study. All participants underwent a polysomnogram to define gold-standard diagnosis according to standard criteria. RESULTS: We found a sensitivity of 93.8% and a specificity of 87.2%. Sensitivity and specificity were similar in healthy volunteers, compared to controls or patients, with other sleep diagnoses. CONCLUSIONS: A single-question screen for RBD may reliably detect disease, with psychometric properties favorably comparable to those reported for longer questionnaires

Family history of idiopathic REM behavior disorder: a multicenter case-control study

OBJECTIVE: To compare the frequency of proxy-reported REM sleep behavior disorder (RBD) among relatives of patients with polysomnogram-diagnosed idiopathic RBD (iRBD) in comparison to controls using a large multicenter clinic-based cohort. METHODS: A total of 316 patients with polysomnography-confirmed iRBD were recruited from 12 RBD study group centers, along with 316 controls matched on sex and age group. All subjects completed a self-administered questionnaire that collected proxy-reported information on family history of tremor, gait trouble, balance trouble, Parkinson disease, memory loss, and Alzheimer disease. The questionnaire also included a single question that asked about possible symptoms of RBD among first-degree relatives (siblings, parents, and children). RESULTS: A positive family history of dream enactment was reported in 13.8% of iRBD cases compared to 4.8% of controls (odds ratio [OR] = 3.9, 95% confidence interval [CI] 2.0-7.7). ORs were increased for both siblings (OR = 6.1, 95% CI 2.1-18.1) and parents (OR = 3.2, 95% CI 1.4-7.8). We found no significant difference in sex, current age (65.3 10.2 vs 66.9 10.2 years), or age at self-reported RBD onset (55.2 11.7 vs 56.6 15.1 years) in possible familial vs sporadic iRBD. No differences were found in family history of tremor, walking and balance troubles, Parkinson disease, memory loss, or Alzheimer disease. CONCLUSION: We found increased odds of proxy-reported family history of presumed RBD among individuals with confirmed iRBD. This suggests the possibility of a genetic contribution to RBD