Gait as a Quantitative Translational Outcome Measure inAngelman Syndrome

Abstract

Angelman Syndrome (AS) is a genetic neurodevelopmental disorder characterized by developmental delay, lack of speech, seizures, intellectual disability, and walking and balance disorders. Recently, motor ability became an interesting outcome measure in AS, as it is broad including ataxia, hypotonia, delayed and abnormal walking and postural movements and affects nearly every individual with AS. We predict that gait presents a strong opportunity for rigorous, reliable, and quantitative metrics with direct translation to evaluate pharmacological, dietary, and genetic therapies. Numerous motoric deficits have been identified clinically. In this study, we used an innovative, automated gait analysis as well as gold standard motor behavioral assays to further delineate components of motor, coordination, balance, and gait impairments in an AS mouse model across development. Our study demonstrated marked global motoric deficits in AS mice, corroborating many previous reports. Uniquely, this is the first report of nuanced and pertinent aberrations in quantitative spatial and temporal components of gait between AS and wildtype littermate controls, that are analogous in AS individuals. These metrics were followed longitudinally to observe the progression of maladaptive gait in AS, a clinical phenotype. This has not been reported previously and contributes a substantial novel metric for therapeutic development. Taken together, these findings demonstrate the robust translational value in the study of nuanced motor outcomes, i.e., gait, for AS, as well as similar genetic syndromes, in the endeavor of therapeutic screening. Lay AbstractMotor behaviors, like ambulation, gross and fine motor skills, coordination and balance, are easily quantifiable and readily translational between humans and preclinical rodent models for neurodevelopmental and neurodegenerative disorders, than other domains of behavior. To that end, we investigated gait across development in a mouse model for Angelman Syndrome and elucidated onset, progression, and decline of motor deficits in innovative, nuanced, and clinically relevant manner.