Complete blood count revealed severe anemia (Hb 5.7 g/dL, MCV 97.8 fL, MCH 32.6 pg, reticulocytes 7200/μL, white blood cells 10,070/μL, and platelets 725,000/μL), while further laboratory investigations were significant only for low B12 vitamin levels (126 pg/mL). This evidence concerns the gene GSTM1 and anemia (phenotype).