1-Deoxysphingosine
1-Deoxysphingosine is elevated in lymphoblasts of individuals with hereditary sensory neuropathy type 1 (HSAN1) disorder; it features a (4E) double bond in its structure and is produced through the catabolism of 1-deoxyceramide catalyzed by the ceramidase enzyme, classifying it as an unsaturated deoxy-sphingoid base.