It is caused by a defect in the gene for cGMP - phosphodiesterase , which leads to retinal levels of cyclic guanosine monophosphate ten times normal .
This type of PRA has an early onset of severe vision loss .
PRA is caused by a defect in the gene for cGMP - phosphodiesterase , which leads to retinal levels of cyclic guanosine monophosphate ten times normal .
This type of PRA has an early onset of severe vision loss .