Childhood-onset dystonia-causing KMT2B variants result in a distinctive genomic hypermethylation profile

Background: Dystonia is a clinically and genetically heterogeneous movement disorder characterized by sustained or intermittent muscle contractions causing abnormal, often repetitive, movements and/or postures. Heterozygous variants in lysine methyltransferase 2B (KMT2B), encoding a histone H3 methyltransferase, have been associated with a childhood-onset, progressive and complex form of dystonia (dystonia 28, DYT28). Since 2016, more than one hundred rare KMT2B variants have been reported, including frameshift, nonsense, splice site, missense and other in-frame changes, many having an uncertain clinical impact. Results: We characterize the genome-wide peripheral blood DNA methylation profiles of a cohort of 18 patients with pathogenic and unclassified KMT2B variants. We resolve the “episignature” associated with KMT2B haploinsufficiency, proving that this approach is robust in diagnosing clinically unsolved cases, properly classifying them with respect to other partially overlapping dystonic phenotypes, other rare neurodevelopmental disorders and healthy controls. Notably, defective KMT2B function in DYT28 causes a non-random DNA hypermethylation across the genome, selectively involving promoters and other regulatory regions positively controlling gene expression. Conclusions: We demonstrate a distinctive DNA hypermethylation pattern associated with DYT28, provide an epigenetic signature for this disorder enabling accurate diagnosis and reclassification of ambiguous genetic findings and suggest potential therapeutic approaches

Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study

Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008–11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003–13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 × 10−10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 × 10−8 DHFR p=8·37 × 10−7 MTRNR2L2 p=2·15 × 10−9) and to a lesser extent in REGISTRY (MSH3 p=9·36 × 10−4 DHFR p=8·45 × 10−4 MTRNR2L2 p=1·20 × 10−3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 × 10−8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16–0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06–0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation

Concordance between severity of disease, prevalence of nonmotor symptoms, patient-reported quality of life and disability and use of medication in Parkinson’s disease

none7noThe aim of this study was to test the concor- dance between disease severity, prevalence of nonmotor symptoms, age, health-related quality of life (HRQoL), disability and medication use in patients with Parkinson’s disease (PD). Severity was classified with the Hoehn and Yahr (HY) scale and Levodopa Equivalent Daily Dose (LEDD) calculated. HRQoL was evaluated with the SF-36, disability with the WHO-DAS II and nonmotor symptoms with the NMSQuest. Patients were clustered using SF-36 and WHO-DAS II into three groups covering the contin- uum from low disability and HRQoL, to severe disability and HRQoL decrement. Contingency Coefficient were used to verify the relationships between clusters and HY stage; ANOVA to evaluate differences in NMS, age and LEDD between clusters; odds ratio to test the likelihood of taking levodopa or dopamine agonist and being member of the three clusters; t test to evaluate differences in LEDD between patients with HY C3 or B2. Eighty-six patients were clustered: 48 had low disability and HRQoL decre- ment, 18 intermediate disability and HRQoL decrement and 20 high disability and HRQoL decrement. A significant relationship was found between PD severity groups, HRQoL and disability profiles. No differences for age and LEDD were observed in the three groups, and those with more disability and lower HRQoL reported a higher number of nonmotor symptoms; patients in HY C3 were prescribed higher doses of drugs. In conclusion, we found a substantial concordance between PD staging, prevalence of nonmotor symptoms and patient-reported HRQoL and disability measures. In our opinion, the SF-36 and the WHO-DAS II can be used for profiling patients.Raggi A; Leonardi M; Covelli V; Albanese A; Soliveri P; Carella F; Romito LRaggi, A; Leonardi, M; Covelli, Venusia; Albanese, A; Soliveri, P; Carella, F; Romito, L

Motor features and response to oral levodopa in patients with Parkinson's disease under continuous dopaminergic infusion or deep brain stimulation

Subthalamic nucleus deep brain stimulation (STN DBS) and continuous dopaminergic infusions (jejunal levodopa or subcutaneous apomorphine) are indicated in complicated Parkinson's disease (PD), although it remains unsettled how they compare to each other

Relationships between disability, quality of life and prevalence of nonmotor symptoms in Parkinson's disease

Patients with Parkinson's disease suffer from a variety of motor and nonmotor symptoms (NMS), report reduced quality of life and increased disability. Aims of this study are to assess the impact of Parkinson's disease on disability and quality of life, to evaluate the relationships between them and NMS prevalence. In this cross-sectional study, adult patients were consecutively enrolled and administered the World Health Organization Disability Assessment Schedule (WHO-DAS II), the 36-Item Short-Form Health Survey (SF-36) and the Non Motor Symptoms Questionnaire (NMSQuest). One-sample t-test was used to compare WHO-DAS II and SF-36 scores with normative value. Pearson's correlation was performed between NMSQuest, WHO-DAS II and SF-36 summary scales. Independent-sample t-test was used to compare NMSQuest, WHO-DAS II and SF-36 scores in patients with Hoehn & Yahr stage <3 and 65 3. In total, 96 patients were enrolled. SF-36 and WHO-DAS II scores were significantly worse than the normative values. Correlation coefficients between NMSQuest, WHO-DAS II and SF-36's mental score were moderate, and were high between WHO-DAS II and and SF-36's physical score. Patients with Hoehn & Yahr stage 65 3 reported reduced quality of life, higher disability and more NMS. Parkinson's disease severity is strongly associated with reduced quality of life, increased disability and NMS prevalence. Disability and quality of life assessment tools measure psychosocial facets that are similar specifically with regard to physical health component of health-related quality of life, are sensitive enough to capture differences related to disease's progression and increased prevalence of NMS

Geographic differences in the incidence of Huntington's disease in Sardinia, Italy

BACKGROUND: The frequency of Huntington's disease (HD) may vary considerably, with higher estimates in non-Asian populations. We have recently examined the prevalence of HD in the southern part of Sardinia, a large Italian Mediterranean island that is considered a genetic isolate. We observed regional microgeographic differences in the prevalence of HD across the study area similar to those recently reported in other studies conducted in European countries. To explore the basis for this variability, we undertook a study of the incidence of HD in Sardinia over a 10-year period, 2009 to 2018.METHODS: Our research was conducted in the 5 administrative areas of Sardinia island. Case patients were ascertained through multiple sources in Sardinia and Italy.RESULTS: During the incidence period 53 individuals were diagnosed with clinically manifested HD. The average annual incidence rate 2009-2018 was 2.92 per 106 persons-year (95% CI, 2.2 to 3.9). The highest incidence rate was observed in South Sardinia (6.3; 95% CI, 4.2-9.5). This rate was significantly higher (p<0.01) than the rates from Cagliari, Oristano, and Sassari provinces but did not significantly differ (p = 0.38) from the Nuoro rate.CONCLUSIONS: The overall incidence of HD in Sardinia is close to the correspondent estimates in Mediterranean countries. Our findings highlight also the possibility of local microgeographic variations in the epidemiology of HD that might reflect several factors, including a possible founder effect in the rural areas of South Sardinia and Nuoro

Long-term safety, discontinuation and mortality in an Italian cohort with advanced Parkinson's disease on levodopa/carbidopa intestinal gel infusion

Introduction Levodopa/carbidopa intestinal gel (LCIG) is an effective treatment in patients with advanced Parkinson's disease (PD) with consolidated evidence of clinical efficacy. However, only few studies have assessed long-term safety, causes of discontinuation, mortality, and relative predictors. Methods We conducted a retrospective analysis of 79 PD patients treated with LCIG between 2005 and 2020 in two Italian Neurological Centers, recording all adverse events (AEs), including weight loss (WL). Kaplan-Meier curve was used to estimate the time to discontinuation and survival. Cox proportional hazard model was employed to identify predictors of discontinuation and mortality, while Pearson's correlation was used to analyze predictors of WL. Results The average follow-up was 47.7 +/- 40.5 months and the median survival from disease onset was 25 years. There were three cases of polyradiculoneuropathy Guillain-Barre syndrome-like, all occurred in the early years of LCIG treatment. Twenty-five patients died (32%), 18 on LCIG (including one suicide) and seven after discontinuation. The mean WL was 3.62 +/- 7.5 kg, which correlated with levodopa dose at baseline (p = 0.002), levodopa equivalent daily dose (LEDD) baseline (p = 0.017) and off-duration (p = 0.0014), but not dyskinesia. Peristomal complications emerged as a negative predictor of discontinuation (p = 0.008). Conclusions LCIG has a relatively satisfactory long-term safety profile and efficacy and a relatively low rate of discontinuation. Peristomal complications may represent a predictor of longer duration of therapy. According to the mortality analysis, LCIG patients show a long lifespan. Delaying the initiation of LCIG does not affect the sustainability of LCIG therapy