N-Acylsphingosine Amidohydrolase 1 (ASAH1)

Acid ceramidase is 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. Two transcript variants encoding distinct isoforms have been identified for this gene. In melanocytic cells ASAH1 gene expression may be regulated by MITF. Defects in ASAH1 are the cause of Farber disease (FD). This sphingolipid disease is characterized by subcutaneous lipid-loaded nodules, excruciating pain in the joints and extremities, marked accumulation of ceramide in lysosomes, and death by three years of age.