Although efforts should be made to use WHO Hb values of 11g/dl as cutoff for anaemia rather than the 10g/dl classification according to the HCS instruction [13], interestingly, studies have shown that there is increase in the performance of the HCS as the haemoglobin level descends towards the range of severe anaemia cutoffs [11, 13, 15]. Here, GSTM1 is linked to anemia (phenotype).