Abstract
Inosine 5′-monophosphate dehydrogenase (IMPDH) is a critical enzyme in the production of guanine nucleotides and an antiproliferative drug target. Recently mutations in IMPDH1 were linked to the RP10 allele of retinitis pigmentosa (RP). The mechanism of disease is puzzling, given that mutations in this ubiquitously expressed enzyme have an effect limited to death of the rod photoreceptors. Some clues to this puzzle include the expression of retina-specific splice variants and their interaction with rhodopsin mRNA.