Spinal muscular atrophy with progressive myoclonic epilepsy (SMA-PME), sometimes called Jankovic–Rivera syndrome, is a very rare neurodegenerative disease whose symptoms include slowly progressive muscle loss (atrophy), predominantly affecting proximal muscles, combined with denervation and myoclonic seizures.

[2] SMA-PME is associated with a missense mutation (c.125C→T) or deletion in exon 2 of the ASAH1 gene and is inherited in an autosomal recessive manner.

[3] SMA-PME is closely related to a lysosomal disorder disease called Farber lipogranulomatosis.

[5] The ASAH1 gene codes for acid ceramidase, an enzyme found in lysosomes.

Myelin is an insulating coating around the neurons in the body which helps to contain bioelectrical signals along a nerve cell's axon and increase transmission rate.