Background: Identifying hereditary parkinsonism is valuable for diagnosis, genetic counseling, patient prioritization in trials, and studying the disease for personalized therapies. However, most studies were conducted in Europeans, and limited data exist on admixed populations like those from Latin America.Objectives: This study aims to assess the frequency and distribution of genetic parkinsonism in Latin America.Methods: We conducted a systematic review and meta‐analysis of the frequency of parkinsonian syndromes associated with genetic pathogenic variants in Latin America. We defined hereditary parkinsonism as those caused by the genes outlined by the MDS Nomenclature of Genetic Movement Disorders and heterozygous carriers of GBA1 pathogenic variants. A systematic search was conducted in PubMed, Web of Science, Embase, and LILACS in August 2022. Researchers reviewed titles and abstracts, and disagreements were resolved by a third researcher. After this screening, five researchers reanalyzed the selection criteria and extracted information based on the full paper. The frequency for each parkinsonism‐related gene was determined by the presence of pathogenic/likely pathogenic variants among screened patients. Cochran's Q and I² tests were used to quantify heterogeneity. Meta‐regression, publication bias tests, and sensitivity analysis regarding study quality were also used for LRRK2‐, PRKN‐, and GBA1‐related papers.Results: We included 73 studies involving 3014 screened studies from 16 countries. Among 7668 Latin American patients, pathogenic variants were found in 19 different genes. The frequency of the pathogenic variants in LRRK2 was 1.38% (95% confidence interval [CI]: 0.52–2.57), PRKN was 1.16% (95% CI: 0.08–3.05), and GBA1 was 4.17% (95% CI: 2.57–6.08). For all meta‐analysis, heterogeneity was high and publication bias tests were negative, except for PRKN, which was contradictory. Information on the number of pathogenic variants in the other genes is further presented in the text.Conclusions: This study provides insights into hereditary and GBA1‐related parkinsonism in Latin America. Lower GBA1 frequencies compared to European/North American cohorts may result from limited access to gene sequencing. Further research is vital for regional prevalence understanding, enabling personalized care and therapies. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Background: Dystonia is associated with disabling nonmotor symptoms like chronic pain (CP), which is prevalent in dystonia and significantly impacts the quality of life (QoL). There is no validated tool for assessing CP in dystonia, which substantially hampers pain management.Objective: The aim was to develop a CP classification and scoring system for dystonia.Methods: A multidisciplinary group was established to develop the Dystonia‐Pain Classification System (Dystonia‐PCS). The classification of CP as related or unrelated to dystonia was followed by the assessment of pain severity score, encompassing pain intensity, frequency, and impact on daily living. Then, consecutive patients with inherited/idiopathic dystonia of different spatial distribution were recruited in a cross‐sectional multicenter validation study. Dystonia‐PCS was compared to validated pain, mood, QoL, and dystonia scales (Brief Pain Inventory, Douleur Neuropathique‐4 questionnaire, European QoL‐5 Dimensions‐3 Level Version, and Burke–Fahn–Marsden Dystonia Rating Scale).Results: CP was present in 81 of 123 recruited patients, being directly related to dystonia in 82.7%, aggravated by dystonia in 8.8%, and nonrelated to dystonia in 7.5%. Dystonia‐PCS had excellent intra‐rater (Intraclass Correlation Coefficient ‐ ICC: 0.941) and inter‐rater (ICC: 0.867) reliability. In addition, pain severity score correlated with European QoL‐5 Dimensions‐3 Level Version's pain subscore (r = 0.635, P < 0.001) and the Brief Pain Inventory's severity and interference scores (r = 0.553, P < 0.001 and r = 0.609, P < 0.001, respectively).Conclusions: Dystonia‐PCS is a reliable tool to categorize and quantify CP impact in dystonia and will help improve clinical trial design and management of CP in patients affected by this disorder. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

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