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Background: Rare movement disorders often have a genetic etiology. New technological advances have increased the odds of achieving genetic diagnoses: next-generation sequencing (NGS) (whole-exome sequencing-WES; whole-genome sequencing-WGS) and long-read sequencing (LRS). In 2017, we launched a WES program for patients with rare movement disorders of suspected genetic etiology. We aim to describe the accumulated experience of a modern movement disorder genetic clinic, highlighting how different available genetic tests might be prioritized according to the clinical phenotype and pattern of inheritance. Methods: Participants were studied through WES analysis. Descriptive statistics, including the mean, standard deviation, counts, and percentages, were used to summarize demographic and clinical characteristics in all subjects and with each type of result [pathogenic or likely pathogenic, variants of uncertain significance (VUS), negative]. Results: We studied 88 patients (93.2% Caucasian, 5.72% African American, and 1.08% Hispanic or Latino). After excluding six family members from four index participants, the diagnostic yield of WES reached 27% (22/82 probands). The age at onset was significantly lower in patients with pathogenic/likely pathogenic variants. The most common clinical phenotypes were ataxia and parkinsonism. Dystonia, ataxia, leukoencephalopathy, and parkinsonism were associated with most genetic diagnoses. Conclusions: We propose a comprehensive protocol with decision tree testing for WGS and LRS, a return of results, and a re-analysis of inconclusive genetic data to increase the diagnostic yield of patients with rare neurogenetic disorders.

According to expert consensus, dystonia can be classified as focal, segmental, multifocal, and generalized, based on the affected body distribution. To provide an empirical and data-driven approach to categorizing these distributions, we used a data-driven clustering approach to compare frequency and co-occurrence rates of non-focal dystonia in pre-defined body regions using the Dystonia Coalition (DC) dataset. We analyzed 1,618 participants with isolated non-focal dystonia from the DC database. The analytic approach included construction of frequency tables, variable-wise analysis using hierarchical clustering and independent component analysis (ICA), and case-wise consensus hierarchical clustering to describe associations and clusters for dystonia affecting any combination of eighteen pre-defined body regions. Variable-wise hierarchical clustering demonstrated closest relationships between bilateral upper legs (distance = 0.40), upper and lower face (distance = 0.45), bilateral hands (distance = 0.53), and bilateral feet (distance = 0.53). ICA demonstrated clear grouping for the a) bilateral hands, b) neck, and c) upper and lower face. Case-wise consensus hierarchical clustering at k = 9 identified 3 major clusters. Major clusters consisted primarily of a) cervical dystonia with nearby regions, b) bilateral hand dystonia, and c) cranial dystonia. Our data-driven approach in a large dataset of isolated non-focal dystonia reinforces common segmental patterns in cranial and cervical regions. We observed unexpectedly strong associations between bilateral upper or lower limbs, which suggests that symmetric multifocal patterns may represent a previously underrecognized dystonia subtype., Competing Interests: JRY’s institution receives grant funding on his behalf from the National Institutes of Health (NIH). BB has received research grant support from the Dystonia Coalition (DC), the Parkinson’s Foundation (PF), the VCU School of Medicine, the Administration for Community Living, and the Dystonia Medical Research Foundation (DMRF). He has received honoraria from the International Parkinson and Movement Disorder Society (MDS) and serves on the medical advisory board of the Benign Essential Blepharospasm Research Foundation (BEBRF) and the National Spasmodic Torticollis Association. HJ has grant support (recent, active, or pending) from the US government (National Institutes of Health), private philanthropic organizations (Cure Dystonia Now), and industry (Addex, Aeon, Revance, Jazz) and has also served on advisory boards or as a consultant for Addex, Allergan, Apello, CoA Therapeutics, Cavion, Daiichi Sankyo, Ipsen, PureTech, Retrophin, Revance and Takaha/Ene. HJ has received honoraria or stipends for lectures or administrative work from the MDS and has also served on the Scientific Advisory Boards for several private foundations including the BEBRF, Cure Dystonia Now, the DMRF, the Tourette Association of America, and Tyler’s Hope for a Cure. JF is funded through an internal grant at the University of Colorado and through a philanthropic grant from the Mowry family. AW reports grant support from the NIH R01NS122943 as PI and RO1 NS121120-01 as a Co-I and reports past funding from BEBRF, DC, DMRF, and National Organization for Rare Disorders. AW has received consultant fees from Merz, Jazz and Acadia and is the current Vice President for the Tremor Research Group and recent advisor for Supernus and Biogen-Sage. AM has been funded by the DMRF, Sunflower Parkinson’s Disease Foundation and the PF. KD has received honoraria from the PF for web support. SP’s institution receives grant funding on her behalf from the NIH (P20 GM109899; U54 NS116025), Department of Defense (W81XWH-19-CTRR-CTA); Aeon, Scion, and she is a member of the Medical Scientific Advisory Committee for the DMRF and the BEBRF (uncompensated); she has received honoraria from American Academy of Neurology and the MDS for educational lectures. AD is funded by Teva (NCT04173260) and serves as site PI for trials from Cerevel, Teva, Lundbeck, and Annovis Bio. NS is an investigator in studies funded by F. Hoffmann-LaRoche Ltd., Neuraly, Inc., UCB Biopharma SPRL, Cerevel Therapeutics, Abbvie, Inc., Praxis Precision Medicines, Inc., DMRF, and NIH grant P50NS108675, and has been a consultant and received honoraria from The Huntington Study Group LTD., and PSG EARSTIM DSMB. SAN’s institution receives grant funding on his behalf from the NIH, DMRF, and Dysphonia International, and he is a member of the Medical Scientific Advisory Committee for the DMRF (uncompensated). The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Study Objectives: To evaluate the health-related quality of life (HRQoL) in patients with upper airway respiratory syndrome (UARS) and obstructive sleep apnea (OSA) compared to the general population (GP) in Lima, Peru, and to explore the variables associated with differences in HRQoL in patients with UARS., Methods: This was a retrospective study of medical and polysomnography records from 2009-2014 in a referral sleep medicine center for patients aged 18-64 years. UARS was defined by polysomnography as follows: apnea-hypopnea index < 5 events/h, oxygen saturation ≥ 92%, respiratory effort-related arousal index ≥ 5. HRQoL was assessed using the 36-Item Short Form Survey (version 1) questionnaire validated in Peru. The GP HRQoL was obtained from a population-based survey. Linear and logistic regression analyses were conducted., Results: We reviewed 1,329 polysomnograms and selected 888. UARS and OSA were diagnosed in 93 and 795 participants, respectively. The GP cohort consisted of 641 participants. Total HRQoL mean scores (95% confidence interval) in patients with UARS, patients with OSA, and the GP were 67.4 (63.7-71.1), 66.9 (65.4-68.4), and 82.9 (81.6-84.3), respectively. Patients with UARS and patients with OSA had a 5.5 times (95% confidence interval, 3.3-9.2) and 6.2 times (95% confidence interval, 4.6-8.4) greater probability of having a low total HRQoL score compared to patients in the GP, respectively. In patients with UARS, muscle pain, use of psychotropic medication, obesity, and depression were negatively correlated with the total HRQoL score., Conclusions: The impact of OSA and UARS on HRQoL is similar between disease groups and markedly worse when compared to the impact in the GP. In patients with UARS, the presence of muscle pain, obesity, female sex, depression, and use of psychotropic medication negatively impacted HRQoL., Citation: Vizcarra-Escobar D, Duque KR, Barbagelata-Agüero F, Vizcarra JA. Quality of life in upper airway resistance syndrome. J Clin Sleep Med. 2022;18(5):1263-1270., (© 2022 American Academy of Sleep Medicine.)

Long-read sequencing (LRS) technologies have been recently introduced to overcome intrinsic limitations of widely-used next-generation sequencing (NGS) technologies, namely the sequencing limited to short-read fragments (150-300 base pairs). Since its introduction, LRS has permitted many successes in unraveling hidden mutational mechanisms. One area in clinical neurology in need of rethinking as it applies to genetic mechanisms is essential tremor (ET). This disorder, among the most common in neurology, is a syndrome often exhibiting an autosomal dominant pattern of inheritance whose large phenotypic spectrum suggest a multitude of genetic etiologies. Exome sequencing has revealed the genetic etiology only in rare ET families ( FUS, SORT1, SCN4A, NOS3, KCNS2, HAPLN4/BRAL2 , and USP46 ). We hypothesize that a reason for this shortcoming may be non-classical genetic mechanism(s) underpinning ET, among them trinucleotide, tetranucleotide, or pentanucleotide repeat disorders. In support of this hypothesis, trinucleotide (e.g., GGC repeats in NOTCH2NLC ) and pentanucleotide repeat disorders (e.g., ATTTC repeats in STARD7 ) have been revealed as pathogenic in patients with a past history of what has come to be referred to as "ET plus," bilateral hand tremor associated with epilepsy and/or leukoencephalopathy. A systematic review of LRS in neurodegenerative disorders showed that 10 of the 22 (45%) genetic etiologies ascertained by LRS include tremor in their phenotypic spectrum, suggesting that future clinical applications of LRS for tremor disorders may uncover genetic subtypes of familial ET that have eluded NGS, particularly those with associated leukoencephalopathy or family history of epilepsy. LRS provides a pathway for potentially uncovering novel genes and genetic mechanisms, helping narrow the large proportion of "idiopathic" ET., Competing Interests: LM has received honoraria from the International Association of Parkinsonism and Related Disorders (IAPRD) Society for social media and web support. MK is an employee of the CONICET and has received grant support from the Ministry of Science and Technology of Argentina and the Ministry of Health of Buenos Aires. AE has received grant support from the NIH and the Michael J Fox Foundation; personal compensation as a consult-ant/scientific advisory board member for Abbvie, Neuroderm, Neurocrine, Amneal, Adamas, Acadia, Acorda, Kyowa Kirin, Sunovion, Lundbeck, and USWorldMeds; publishing royalties from Lippincott Williams & Wilkins, Cambridge University Press, and Springer; and honoraria from USWorldMeds, Acadia, and Sunovion. He is cofounder of REGAIN Therapeutics, owner of a provisional patent on compositions and methods for treatment and/or prophylaxis of proteinopathies. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Marsili, Duque, Bode, Kauffman and Espay.)

The gold standard for classification of neurodegenerative diseases is postmortem histopathology; however, the diagnostic odyssey of this case challenges such a clinicopathologic model. We evaluated a 60-year-old woman with a 7-year history of a progressive dystonia-ataxia syndrome with supranuclear gaze palsy, suspected to represent Niemann-Pick disease Type C. Postmortem evaluation unexpectedly demonstrated neurodegeneration with 4-repeat tau deposition in a distribution diagnostic of progressive supranuclear palsy (PSP). Whole-exome sequencing revealed a new heterozygous variant in TGM6 , associated with spinocerebellar ataxia type 35 (SCA35). This novel TGM6 variant reduced transglutaminase activity in vitro, suggesting it was pathogenic. This case could be interpreted as expanding: (1) the PSP phenotype to include a spinocerebellar variant; (2) SCA35 as a tau proteinopathy; or (3) TGM6 as a novel genetic variant underlying a SCA35 phenotype with PSP pathology. None of these interpretations seem adequate. We instead hypothesize that impairment in the crosslinking of tau by the TGM6 -encoded transglutaminase enzyme may compromise tau functionally and structurally, leading to its aggregation in a pattern currently classified as PSP. The lessons from this case study encourage a reassessment of our clinicopathology-based nosology.

Children in the Peruvian Amazon Basin are at risk of soil-transmitted helminths (STH) infections. This study aimed to determine the prevalence of STH infection in children from a rural Amazonian community of Peru and to elucidate epidemiological risk factors associated with its perpetuation while on a school-based deworming program with mebendazole. Stool samples of children aged 2-14 years and their mothers were analyzed through direct smear analysis, Kato-Katz, spontaneous sedimentation in tube, Baermann's method, and agar plate culture. A questionnaire was administered to collect epidemiological information of interest. Among 124 children, 25.8% had one or more STH. Individual prevalence rates were as follows: Ascaris lumbricoides , 16.1%; Strongyloides stercoralis , 10.5%; hookworm, 1.6%; and Trichuris trichiura , (1.6%). The prevalence of common STH ( A. lumbricoides , T. trichiura , and hookworm) was higher among children aged 2-5 years than older children (31.6% versus 12.8%; P = 0.01). In terms of sanitation deficits, walking barefoot was significantly associated with STH infection (OR = 3.28; CI 95% = 1.11-12.07). Furthermore, STH-infected children more frequently had a mother who was concomitantly infected by STH than the non-STH-infected counterpart (36.4% versus 14.1%, P = 0.02). In conclusion, STH infection is highly prevalent in children from this Amazonian community despite routine deworming. Institutional health policies may include hygiene and sanitation improvements and screening/deworming of mothers to limit the dissemination of STH. Further studies are needed to address the social and epidemiological mechanics perpetuating these infections.

Abstract: Cyclic alternating pattern (CAP) is widely recognized as an expression of sleep instability in electroencephalogram activity during non-rapid eye movement sleep. We report a case with sequences of CAP followed by bruxism and catathrenia in a 10-y-old male patient with a diagnosis of attention deficit hyperactivity disorder in treatment with methylphenidate. We found CAP in 83.1% of all episodes of catathrenia, and the CAP rate was 12.8%. We propose to consider catathrenia as one of the sleep disorders that may be accompanied by CAP., (© 2017 American Academy of Sleep Medicine)