In the search for an explanation for this rarity, it has been found that the patient has a seldom-seen allelic combination. One allele is a non-functional null allele, while the other encodes for a partially active enzyme. Furthermore, the partially functional allele has expression deficits that depend on the cell type in which it is expressed. Therefore, some of the patient's cells have a considerable amount of RPI activity, whereas others do not. The molecular cause of the pathology is not fully understood. One hypothesis is that<unk> -5-phosphate may be insufficient for RNA synthesis. Another possibility is that the accumulation of D-ribitol and D-arabitol may be toxic.
Ribose-5-phosphate isomerase deficiency
Triosephosphate isomerase deficiency
Arginine:glycine amidinotransferase deficiency
Adenine phosphoribosyltransferase deficiency
Glutaminase deficiency
Galactose-1-phosphate uridylyltransferase deficiency
Malonyl-CoA decarboxylase deficiency
Carbamoyl phosphate synthetase I deficiency