Glucose-6-phosphate dehydrogenase, hexokinase and pyruvate kinase activities in erythrocytes of neonates and adults in Basrah

Abstract

The mean activities (95% confidence interval; number of patients) for erythrocyte glucose-6-phosphate dehydrogenase (G6PD), hexokinase (HK), and pyruvate kinase (PK) in haemolysate of clinically normal neonates from Basrah, Iraq were found to be 3.29 (0.10; n = 456), 0.61 (0.02; n = 219), and 5.10 (0.07; n = 500), respectively, all expressed as U/10(10) RBC at 37 degrees C. Comparative values for apparently healthy adults were: 2.14 (0.06; n = 186), 0.41 (0.02; n = 46), and 3.61 (0.07; n = 243). Differences between sexes in the mean activities of each of the three enzymes were not significant (p > 0.5), being several times less than the corresponding 95% confidence intervals. However, differences were highly significant between neonates and adults (p < 0.001), presumably reflecting the greater proportion of 'young' cells and/or their programming for higher activity in cord blood. The neonate-adult difference (95% confidence interval) for each enzyme was: G6PD, 1.15 (0.43); HK, 0.20 (0.14); and PK, 1.49 (0.64). Some degree of G6PD-deficiency was observed in 7.9% of male and 9.7% of female neonates, whereas the frequency in adults was 9.2% and 11.8% for males and females, respectively. The higher frequency in females accords with expectations based on gene frequency estimations.

Archived Unfrozen Neonatal Blood Spots Are Amenable to Quantitative Gene Expression Analysis

“…HK1, a metabolic gene expressed in higher number in neonatal erythrocytes [37], gave Ct values before 35 cycles for 26/36 assays (72%) and was present in all (12/12) samples. MRPL11 gave Ct values before 35 cycles for 24/36 assays (67%, 11/12 samples).…”