GSTM1 and anemia (phenotype): A full blood count typically reveals moderate macrocytic anaemia, with a haemoglobin (Hb) of 66–116 g/l (mean 92 g/l), mean corpuscular volume (MCV) 100–120 and reticulocytopenia, although 30% of cases have a normal MCV (Wickramasinghe, 1998).