Inosine monophosphate dehydrogenase family
inosine monophosphate dehydrogenase family
Inosine-5′-monophosphate dehydrogenase (IMPDH) is an essential enzyme in purine biosynthesis where it catalyzes the first committed step in GTP synthesis. In humans, there are two isoforms of IMPDH that share 84% sequence identity: IMPDH2 is up-regulated in proliferating cells while IMPDH1 plays a housekeeping role and is expressed in most tissues. Missense mutations in both genes lead to disease in humans. Mutations in IMPDH1 result in autosomal dominant blindness in the form of retinitis pigmentosa (RP) or Leber congenital amaurosis (LCA). Mutations in IMPDH2 are associated with severe juvenile neuropathies.