Tracing the Distribution of European Lactase Persistence Genotypes Along the Americas

In adulthood, the ability to digest lactose, the main sugar present in milk of mammals, is a phenotype (lactase persistence) observed in historically herder populations, mainly Northern Europeans, Eastern Africans, and Middle Eastern nomads. As the –13910∗T allele in the MCM6 gene is the most well-characterized allele responsible for the lactase persistence phenotype, the –13910C > T (rs4988235) polymorphism is commonly evaluated in lactase persistence studies. Lactase non-persistent adults may develop symptoms of lactose intolerance when consuming dairy products. In the Americas, there is no evidence of the consumption of these products until the arrival of Europeans. However, several American countries’ dietary guidelines recommend consuming dairy for adequate human nutrition and health promotion. Considering the extensive use of dairy and the complex ancestry of Pan-American admixed populations, we studied the distribution of –13910C > T lactase persistence genotypes and its flanking haplotypes of European origin in 7,428 individuals from several Pan-American admixed populations. We found that the –13910∗T allele frequency in Pan-American admixed populations is directly correlated with allele frequency of the European sources. Moreover, we did not observe any overrepresentation of European haplotypes in the –13910C > T flanking region, suggesting no selective pressure after admixture in the Americas. Finally, considering the dominant effect of the –13910∗T allele, our results indicate that Pan-American admixed populations are likely to have higher frequency of lactose intolerance, suggesting that general dietary guidelines deserve further evaluation across the continent

Distonía del músico: fenomenología y desencadenantes vinculados a la ejecución musical

Resumen: Las distonías se definen como una contracción conjunta, sostenida e involuntaria de músculos agonistas y antagonistas, que puede causar torsión, movimientos involuntarios anormales repetitivos y/o posturas anormales. Un grupo especial de distonías son las conocidas como ocupacionales, que incluyen trastornos distónicos desencadenados por una actividad motora repetitiva, relacionada con la actividad profesional o tarea específica. Los músicos son una población especialmente vulnerable a este tipo de distonías que se presentan como una pérdida de coordinación y control motor voluntario de movimientos altamente entrenados en la interpretación musical. Nuestro objetivo es describir una serie clínica de distonías focales en músicos evaluados y tratados en nuestro centro. Pacientes y métodos: Se presentan los datos de una serie clínica de 12 músicos con distonía ocupacional; se describen sus antecedentes y fenomenología, así como su evolución después de de la terapia. Resultados: Antecedentes demográficos: edad promedio 34,8 ± 11,8 años, 10 hombres (83,3%) y 2 mujeres (16,7%). Antecedentes médicos: antecedentes traumáticos en segmento distónico, 6 pacientes (50%); antecedentes familiares de enfermedades neurológicas en parientes de primer grado, 6 pacientes (50%); antecedentes laborales según categoría musical, 8 pacientes (66,6%) eran músicos clásicos y 4 pacientes (33,3%) eran músicos populares. Fenomenología: El cuadro distónico se caracterizó por presentarse a una edad promedio de inicio de 28,2 ± 11,3 años (rango 18-57 años). En 11 pacientes el segmento afectado fue la mano (91,7%). De todos los músicos consultados, un total de 9 (75%) recibió terapia. En la mayoría de los pacientes se describen desencadenantes específicos de la ejecución musical, asociados a requerimientos de control motor fino. Cabe mencionar que el 50% de los músicos tratados mantuvo su actividad laboral o puesto en la orquesta a la que pertenecía. Conclusiones: La mayoría de nuestros hallazgos fenomenológicos son coherentes con la literatura actualmente disponible. Sin embargo, nos parece destacable la presencia de desencadenantes atribuibles a requerimientos específicos de la ejecución musical, ligados a la participación del control motor fino. Abstract: Dystonias are defined as a joint sustained and involuntary contraction of agonist and antagonist muscles, which can cause torsion, repetitive abnormal involuntary movements, and/or abnormal postures. One special group of dystonias are those known as occupational, which include dystonia disorders triggered by a repetitive motor activity associated with a specific professional activity or task. Musicians are a population particularly vulnerable to these types of dystonia, which are presented as a loss of coordination and voluntary motor control movements highly trained in musical interpretation. Our aim is to describe a clinical series of focal dystonias in musicians evaluated and treated in our centre. Patients and methods: Data is presented on a clinical series of 12 musicians with occupational dystonia. Their history and phenomenology are described, as well as well as their outcome after therapy. Results: Demographic details: Mean age 34.8 ± 11.8 years, 10 males (83.3%) and 2 females (16.7%). Clinical history: History of trauma in dystonic segment, 6 patients (50%); family history of neurological diseases in first-degree relatives, 6 patients (50%); occupational history according to music category, 8 patients (66.6%) were classical musicians and 4 patients (33.3%) were popular musicians. Phenomenology: The dystonia syndrome was characterised by having a mean age of onset of 28.2 ± 11.3 years (range 18-57 years). The segment affected was the hand (91.7%) in 11patients. Of all the musicians seen in the clinic, 9 of them (75%) received therapy. The majority of patients appeared to have triggering factors specific to musical execution and linked to the requirement of fine motor control. It should be mentioned that 50% of the musicians treated maintained their professional activity or position in the orchestra to which they belonged. Conclusions: The majority of our phenomenological findings are consistent with those reported in the current literature. However, it is worth mentioning the presence of triggering factors attributed to the specific requirements of performing music, linked to the participation of fine motor control. Palabras clave: Distonía focal, Músico, Tratamiento, Rehabilitación, Entrenamiento sensorial, Ocupación, Keywords: Focal dystonia, Musician, Treatment, Rehabilitation, Sensory training, Occupatio

Focal dystonia in musicians: Phenomenology and musical triggering factors

Dystonias are defined as a joint sustained and involuntary contraction of agonist and antagonist muscles, which can cause torsion, repetitive abnormal involuntary movements, and/or abnormal postures. One special group of dystonias are those known as occupational, which include dystonia disorders triggered by a repetitive motor activity associated with a specific professional activity or task. Musicians are a population particularly vulnerable to these types of dystonia, which are presented as a loss of coordination and voluntary motor control movements highly trained in musical interpretation. Our aim is to describe a clinical series of focal dystonias in musicians evaluated and treated in our centre. Patients and methods: Data are presented on a clinical series of 12 musicians with occupational dystonia. Their history and phenomenology are described, as well as well as their outcome after therapy. Results: Demographic details: Mean age 34.8 ± 11.8 years, 10 males (83.3%) and 2 females (16.7%). Clinical history: History of trauma in dystonic segment, 6 patients (50%); family history of neurological diseases in first-degree relatives, 6 patients (50%). Occupational history according to music category: 8 patients (66.6%) were classical musicians and 4 patients (33.3%) were popular musicians. Phenomenology: Dystonia syndrome was characterised by having a mean age of onset of 28.2 ± 11.3 years (range 18–57 years). The segment affected was the hand (91.7%) in 11 patients. Of all the musicians seen in the clinic, 9 of them (75%) received therapy. The majority of patients appeared to have triggering factors specific to musical execution and linked to the requirement of fine motor control. It should be mentioned that 50% of the musicians treated maintained their professional activity or position in the orchestra to which they belonged. Conclusions: The majority of our phenomenological findings are consistent with those reported in the current literature. However, it is worth mentioning the presence of triggering factors attributed to the specific requirements of performing music, linked to the participation of fine motor control. Resumen: Las distonías se definen como una contracción conjunta, sostenida e involuntaria de músculos agonistas y antagonistas, que puede causar torsión, movimientos involuntarios anormales repetitivos y/o posturas anormales. Un grupo especial de distonías son las conocidas como ocupacionales, que incluyen trastornos distónicos desencadenados por una actividad motora repetitiva, relacionada con la actividad profesional o tarea específica. Los músicos son una población especialmente vulnerable a este tipo de distonías que se presentan como una pérdida de coordinación y control motor voluntario de movimientos altamente entrenados en la interpretación musical. Nuestro objetivo es describir una serie clínica de distonías focales en músicos evaluados y tratados en nuestro centro. Pacientes y métodos: Se presentan los datos de una serie clínica de 12 músicos con distonía ocupacional; se describen sus antecedentes y fenomenología, así como su evolución después de de la terapia. Resultados: Antecedentes demográficos: edad promedio 34,8 ± 11,8 años, 10 hombres (83,3%) y 2 mujeres (16,7%). Antecedentes médicos: antecedentes traumáticos en segmento distónico, 6 pacientes (50%); antecedentes familiares de enfermedades neurológicas en parientes de primer grado, 6 pacientes (50%); antecedentes laborales según categoría musical, 8 pacientes (66,6%) eran músicos clásicos y 4 pacientes (33,3%) eran músicos populares. Fenomenología: El cuadro distónico se caracterizó por presentarse a una edad promedio de inicio de 28,2 ± 11,3 años (rango 18–57 años). En 11 pacientes el segmento afectado fue la mano (91,7%). De todos los músicos consultados, un total de 9 (75%) recibió terapia. En la mayoría de los pacientes se describen desencadenantes específicos de la ejecución musical, asociados a requerimientos de control motor fino. Cabe mencionar que el 50% de los músicos tratados mantuvo su actividad laboral o puesto en la orquesta a la que pertenecía. Conclusiones: La mayoría de nuestros hallazgos fenomenológicos son coherentes con la literatura actualmente disponible. Sin embargo, nos parece destacable la presencia de desencadenantes atribuibles a requerimientos específicos de la ejecución musical, ligados a la participación del control motor fino. Keywords: Focal dystonia, Musician, Treatment, Rehabilitation, Sensory training, Occupation, Palabras clave: Distonía focal, Músico, Tratamiento, Rehabilitación, Entrenamiento sensorial, Ocupació

Focal dystonia in musicians

Introduction: A special group of focal dystonia is that known as occupational, which include dystonic disorders triggered by repetitive motor activity, closely associated with the professional activity of a specific task that the affected person performs. In this sense, musicians are a population particularly vulnerable to this disorder, which is presented during the execution of highly trained movements. Objective: This article reviews the pathophysiology of focal dystonia and its therapeutic implications. Development: The pathophysiological basis of focal dystonia in the musician is still not well established. However, due to the contribution of neurophysiological studies and functional neuroimaging, there is growing evidence of anomalies in the processing of sensory information, sensorimotor integration, cortical and subcortical inhibitory processes, which underline this disease.Clinically, it is characterised by the appearance of involuntary muscle contractions, and is associated with loss of motor control while practicing music. It is a gradual appearance and sometimes there may be a history of musculoskeletal injuries or nonphysiological postures preceding the appearance of the symptoms. The neurological examination is usually normal, although subtle dystonic postures can develop spontaneously or with movements that involve the affected segments. The dystonia remains focal and is not generalised. Conclusions: Treatment is based on using multiple strategies for the management of the dystonia, with variable results. Although a specific therapy has not been defined, there are general principles that are combined in each situation looking for results. This includes, among others, pharmacological interventions, management with botulinum toxin, and sensory re-training techniques. Resumen: Introducción: : Un grupo especial de distonía focal son las conocidas como ocupacionales, las que incluyen trastornos distónicos desencadenados por una actividad motora repetitiva, íntimamente relacionada con la actividad profesional o tarea específica que realiza el afectado. En este sentido los músicos son una población especialmente vulnerable a esta patología, que se presenta durante la ejecución de movimientos altamente entrenados. Objetivo: En este manuscrito se revisa la fisiopatología y sus implicancias terapéuticas. Desarrollo: Las bases fisiopatológicas de la distonía focal del músico aún no se conocen completamente. Sin embargo, gracias al aporte de estudios neurofisiológicos y de neuroimágenes funcionales, existe creciente evidencia de alteraciones en el procesamiento de información sensorial, integración sensorio-motora, procesos corticales y subcorticales de inhibición, que subyacen a esta patología.Clínicamente, se caracteriza por aparición de contracción muscular involuntaria y se asocia a pérdida del control motor durante la ejecución musical. Es de aparición gradual y ocasionalmente pueden existir antecedentes de lesiones musculoesqueléticas o posturas no fisiológicas que anteceden la aparición de los síntomas. El examen neurológico es usualmente normal, aunque pueden desarrollarse posturas distónicas sutiles espontáneamente o con movimientos que involucran los segmentos afectados. La distonía permanece focal y no se generaliza. Conclusiones: El tratamiento se basa en la utilización de múltiples estrategias para el manejo de la distonía, con resultado variables. Si bien no se ha definido una terapia especifica, existen principios generales que se combinan en cada situación buscando obtener resultados. Esto incluye intervenciones desde una perspectiva farmacológica, manejo con toxina botulínica, técnicas de reentrenamiento sensorial, entre otras. Keywords: Focal dystonia, Musician, Pathophysiology, Treatment, Botulin toxin, Sensory training, Palabras clave: Distonía focal, Músico, Fisiopatología, Tratamiento, Toxina botulínica, Entrenamiento sensoria

How kinesin-2 forms a stalk

The two distinct motor domains KLP11 and KLP20 of Caenorhabditis elegans kinesin-2 require a dimerization seed of two heptads at the C terminus of the stalk to promote heterodimerization along the entire length of the stalk. This short sequence bears great potential for generating specific heterodimerization in other protein biochemical applications

Genome-Wide Analysis of Copy Number Variation in Latin American Parkinson's Disease Patients

Background Parkinson's disease is the second most common neurodegenerative disorder and affects people from all ethnic backgrounds, yet little is known about the genetics of Parkinson's disease in non-European populations. In addition, the overall identification of copy number variants at a genome-wide level has been understudied in Parkinson's patients. The objective of this study was to understand the genome-wide burden of copy number variants in Latinos and its association with Parkinson's disease. Methods We used genome-wide genotyping data from 747 Parkinson's disease patients and 632 controls from the Latin American Research Consortium on the Genetics of Parkinson's disease. Results Genome-wide copy number burden analysis showed that patients were significantly enriched for copy number variants overlapping known Parkinson's disease genes compared with controls (odds ratio, 3.97; 95%CI, 1.69-10.5; P = 0.018). PRKN showed the strongest copy number burden, with 20 copy number variant carriers. These patients presented an earlier age of disease onset compared with patients with other copy number variants (median age at onset, 31 vs 57 years, respectively; P = 7.46 x 10(-7)). Conclusions We found that although overall genome-wide copy number variant burden was not significantly different, Parkinson's disease patients were significantly enriched with copy number variants affecting known Parkinson's disease genes. We also identified that of 250 patients with early-onset disease, 5.6% carried a copy number variant on PRKN in our cohort. Our study is the first to analyze genome-wide copy number variant association in Latino Parkinson's disease patients and provides insights about this complex disease in this understudied population. (c) 2020 International Parkinson and Movement Disorder Societ