Display omitted •FAME2, compared to EPM1, had confined beta-cortico-muscular coherence (CMC) and increased centrality index in the sensorimotor region contralateral to movement.•In FAME2, CMC distribution and increased centrality index could counteract the severity and the spreading of the myoclonus.•In FAME2, there was a main decline in the network connectivity indexes, possibly linked to neuropsychological comorbidities. Familial Adult Myoclonic Epilepsy (FAME) presents with action-activated myoclonus, often associated with epilepsy, sharing various features with Progressive Myoclonic Epilepsy (PMEs), but with slower course and limited motor disability. We aimed our study to identify measures suitable to explain the different severity of FAME2 compared to EPM1, the most common PME, and to detect the signature of the distinctive brain networks. We analyzed the EEG-EMG coherence (CMC) during segmental motor activity and indexes of connectivity in the two patient groups, and in healthy subjects (HS). We also investigated the regional and global properties of the network. In FAME2, differently from EPM1, we found a well-localized distribution of beta-CMC and increased betweenness-centrality (BC) on the sensorimotor region contralateral to the activated hand. In both patient groups, compared to HS, there was a decline in the network connectivity indexes in the beta and gamma band, which was more obvious in FAME2. In FAME2, better localized CMC and increased BC in comparison with EPM1 patients could counteract the severity and the spreading of the myoclonus. Decreased indexes of cortical integration were more severe in FAME2. Our measures correlated with different motor disabilities and identified distinctive brain network impairments.