BACKGROUND AND OBJECTIVES: Spinal muscular atrophy with progressive myoclonic epilepsy (SMA-PME) due to acid ceramidase deficiency is a rare disorder, allelic with Farber disease, resulting from recessive METHODS: We identified 9 patients with SMA-PME from 5 different families followed in neurology, rehabilitation, and genetics departments of university hospitals in France and the United States. During disease progression, motor functional scores were assessed for seven of them and C26-ceramide quantification on dried blood spots (DBSs) was performed for 4 of them. An RESULTS: Twelve years after the molecular characterization of SMA-PME, here we present the detailed history of 9 patients from 5 different families with 4 new DISCUSSION: This study presents the detailed natural history of SMA-PME. Given the rarity of this disease and the current lack of a reliable biomarker for patient follow-up, this work may serve as a retrospective control group for future therapeutic trials.