Patients with the haemoglobin (Hb) genotypes homozygous sickle cell disease, (HbSS), sickle βeta thalasaemia0, (HbSβ0) and haemoglobin SOArab, (HbSOA) are known to have more severe disease compared to those with milder genotypes such as haemoglobin SC, (Hb SC), and sickle βeta thalassemia+, (HbSβ+) [3]. Here, GSTM1 is linked to sickle cell disease.