Deletional Hb H disease refers to the deletion removing both alpha globin genes on one chromosome 16 such as the SEA type of α0-thalassemia plus a deletion removing only a single alpha globin gene on the other chromosome 16 such as the 3.7 kb deletion (α3.7) or the 4.2 kb deletion (α4.2) [27]. Here, GSTM1 is linked to glycogen storage disease VI.