Enzyme found in humans
Dehydrodolichyl diphosphate synthase is an enzyme that in humans is encoded by the DHDDS gene.[5][6]
Function
Dehydrodolichyl diphosphate (dedol-PP) synthase catalyzes cis-prenyl chain elongation to produce the polyprenyl backbone of dolichol, a glycosyl carrier lipid required for the biosynthesis of several classes of glycoproteins.[6]
Clinical significance
It has been suggested that missense mutations in the DHDDS gene are responsible for certain variants of retinitis pigmentosa.[7] Since it is involved in the early steps of dolichol synthesis, vital e.g. for correct N-glycosylation, a disease caused by mutations in DHDDS should be considered a congenital disorder of glycosylation (and named DHDDS-CDG according to the novel nomenclature of CDGs).[8] Many CDG subtypes present with retinitis pigmentosa as a major feature.[9]