Disturbances of cerebral purine and pyrimidine metabolism in young children with chronic renal failure.

Chronic renal failure during childhood may be associated with delayed cognitive development. From 10 children with chronic renal failure, aged 2-59 months, plasma and cerebrospinal fluid (CSF) purines and pyrimidines have been determined. A marked increase of pseudouridine and cytidine was demonstrated in CSF of 10 and 8 children, respectively. The plasma concentration of pseudouridine was increased in a varying degree to a maximal value of more than 10 times the upper limit of normal. The plasma concentration of cytidine showed only moderately elevated values. In 3 children the study of CSF and plasma was repeated 6 weeks after the start of continuous ambulatory peritoneal dialysis. The abnormal concentrations of pseudouridine and cytidine were still present in CSF and plasma. Further studies are necessary to elucidate the cause of this unknown biochemical aberration of the central nervous system.