G6PD and Jaundice: Among intermediate phenotypes, 80% were identified as either deficient or intermediate, allowing a better identification of neonates at potential jaundice risk as compared with the currently used FST-based diagnosis.14 30 Poor performance of FST can be explained by the higher G6PD enzymatic activity at birth as compared with adulthood31 32; this is probably the result of several haematological factors including younger red cell age, increased number of reticulocytes with higher G6PD activity33 34 and higher white cell count28 as observed here.