RESUMEN
AIM: To evaluate early dystonic features in children and adolescents with SGCE-myoclonus-dystonia. METHOD: In this cross-sectional study, 49 patients (26 females and 23 males) with SGCE-myoclonus-dystonia (aged 15y 2mo, SD 12y) with childhood-onset (2y 10mo, SD 1y 10mo) dystonia were examined using a standardized video recorded protocol. Dystonia was rated using the Writer's Cramp and Gait Dystonia Rating Scales. Disability and impairment for handwriting and walking were also rated. RESULTS: Dystonia was present at rest (n=1), posture (n=12), and during specific motor tasks (n=45) such as writing (n=35), walking (n=23), and running (n=20). Most children reported disability while performing these tasks. Early dystonic patterns were identified for writer's cramp and gait dystonia, the latter named the 'circular shaking leg', 'dragging leg', and 'hobby-horse gait' patterns. Sensory tricks were used by five and eight children to improve dystonia and myoclonus during writing and walking respectively. The rating scales accurately measured the severity of action dystonia and correlated with self-reported disability. INTERPRETATION: Children with SGCE-myoclonus-dystonia show recognizable dystonic patterns and sensory tricks that may lead to an early diagnosis and timely therapeutic approach. Isolated writer's cramp is a key feature in childhood and should prompt SCGE analysis. The proposed action dystonia scales could be used to monitor disease course and response to treatment. WHAT THIS PAPER ADDS: Most children with SGCE-myoclonus-dystonia got writer's cramp and had walking and running dystonia. Writer's cramp was a key feature and should prompt SGCE genetic investigation. 'Circular shaking leg', 'dragging leg', and 'hobby-horse gait' were recognized as early gait patterns. Children used sensory tricks to improve myoclonus and dystonia, suggesting common pathophysiological mechanisms. Action dystonia rating scales are valid tools to assess severity in children.
Asunto(s)
Distonía , Trastornos Distónicos , Trastornos del Movimiento , Mioclonía , Niño , Femenino , Humanos , Masculino , Estudios Transversales , Distonía/diagnóstico , Trastornos Distónicos/diagnóstico , Mioclonía/diagnóstico , Mioclonía/genética , Sarcoglicanos/genéticaRESUMEN
INTRODUCCIÓN: La discinesia de la mutación ADCY5 es un raro trastorno del movimiento de inicio en la infancia. Se caracteriza por movimientos coreicos aislados o asociados a mioclonías y distonías que afectan a las extremidades, el cuello y la cara. El escaso número de pacientes y familias no permite aún una adecuada relación genotipo-fenotipo. OBJETIVOS: Presentar el caso de un niño con trastornos del movimiento de inicio precoz en el seno de una familia con tres generaciones de afectados, y realizar una revisión actualizada de la casuística y el tratamiento de esta rara enfermedad. CASO CLÍNICO: Varón de 6 años, remitido por retraso del lenguaje e hiperactividad. Tras seis meses de seguimiento, comenzó a presentar movimientos coreicos de predominio facial y de la raíz de los miembros, especialmente al despertar. Al año de seguimiento, se evidenció corea generalizado en reposo con afectación orofacial y torpeza en la marcha. Como antecedentes familiares destacaban su madre, abuelo, tío y prima maternos, que fueron diagnosticados de síndrome de Meige (distonía oromandibular y músculos periorbitarios) con trastornos del movimiento de tipo coreiforme sin filiar desde la infancia. El estudio cerebral por resonancia magnética no presentó alteraciones. Se realizó un exoma clínico dirigido a trastornos del movimiento que descubrió la mutación patógena en el gen ADCY5 causante de la discinesia familiar autosómica. CONCLUSIÓN: La mutación c.1126G > A p.A376T muestra una historia natural con un fenotipo clínico no progresivo en tres generaciones de afectados, con inicio en la infancia y respuesta al tratamiento con guanfacina
INTRODUCTION. Dyskinesia of the ADCY5 mutation is a rare movement-onset disorder in childhood. It is characterized by isolated chorea movements or associated with myoclonus and dystonia affecting the limbs, neck and face. The low number of patients and families still does not allow an adequate genotype-phenotype relationship. AIMS. The case of a child with movement disorders of early onset is presented in a family with three generations of affected members. An updated review of the casuistry and management of this rare disease is made. CASE REPORT: A 6-year-old boy referred for language delay and hyperactivity. After six months of follow-up he begins to show chorea movements of predominantly facial and limb roots, especially when waking up. At one year of follow-up, generalized chorea at rest with orofacial involvement and awkward gait begins to show. His family history includes his mother, grandfather, maternal uncle and cousin, who were diagnosed with Meige's syndrome (oromandibular dystonia and periorbital muscles) with choreiform-like movement disorders without affiliation since childhood. The brain study by MRI showed no alterations. A clinical exome targeting movement disorders was performed that discovered the pathogenic mutation in the ADCY5 gene causing autosomal familial dyskinesia. CONCLUSION: The c.1126G>A p.A376T mutation shows a natural history with a non-progressive clinical phenotype in three generations of affected members, with childhood debut and response to guanfacine treatment