PURINE AND PYRIDINE-NUCLEOTIDE METABOLISM IN THE ERYTHROCYTES OF PATIENTS WITH RETT-SYNDROME

The possible involvement of purine and pyridine metabolism in Rett syn drome, a neurodegenerative disorder of unknown aetiology affecting fem ales, was investigated. The levels of purine and pyridine nucleotides and their metabolites were determined by HPLC in the erythrocytes and plasma of 31 Rett patients and of 17 age-matched controls. Nucleotide production rate from extracellular precursors was determined in intact cells and enzyme activities were assayed in crude lysates using the s ame HPLC method. Decreased plasma nicotinamide concentrations and lowe r erythrocyte activities of hypoxanthine phosphoribosyl transferase, a denine phosphoribosyl transferase and phosphoribosylpyrophosphate synt hetase were observed in Rett children compared with age-matched contro ls, while the production rate of IMP from hypoxanthine and of total py ridine nucleotides from nicotinic acid by intact erythrocytes was sign ificantly increased, No significant difference was found in any of the other parameters examined. These findings give a nem contribution to the knowledge of the biochemical alterations in Rett syndrome and enco urage further investigations in the nucleotide field.