The ASAH1 gene encodes in humans the acid ceramidase enzyme. This gene encodes a heterodimeric protein consisting of a nonglycosylated alpha subunit and a glycosylated beta subunit that is cleaved to the mature enzyme posttranslationally. The encoded protein catalyzes the synthesis and degradation of ceramide into sphingosine and fatty acid. Mutations in this gene have been associated with a lysosomal storage disorder known as Farber disease and, recently, with a rare neurodegenerative condition known as spinal muscular atrophy with progressive myoclonic epilepsy. Two transcript variants encoding distinct isoforms have been identified for this gene. In melanocytic cells ASAH1 gene expression may be regulated by MITF.