Meta-Biol

• Pathways

Polyprenol reductase (SRD5A3), resident on the endoplasmic reticulum membrane, mediates the reduction of the alpha-isoprene unit of polyprenol (pPNOL) to form dolichol (DCHOL) in a NADPH-dependent manner (Cantagrel et al. 2010). Defects in SRD5A3 cause congenital disorder of glycosylation 1q (SRD5A3-CDG, CDG1Q; MIM:612379), a neurodevelopmental disorder characterised by under-glycosylated serum glycoproteins resulting in nervous system development, psychomotor retardation, hypotonia, coagulation disorders and immunodeficiency (Cantagrel et al. 2010, Kasapkara et al. 2012). Defects in SRD5A3 can also cause Kahrizi syndrome (KHRZ; MIM:612713), a neurodevelopmental disorder characterised by mental retardation, cataracts, coloboma, kyphosis, and coarse facial features (Kahrizi et al. 2011).