Motor Neuronopathy With Widespread Fasciculations in MCM3AP‐Related Disorder: Clinical and Muscle MRI Insights

Biallelic pathogenic variants in MCM3AP, encoding the germinal center–associated nuclear protein (GANP), have been linked to autosomal recessive peripheral neuropathies variably accompanied by cognitive impairment and multisystem involvement. To date, anterior horn cell involvement has not been documented in association with MCM3AP‐related disorders.