A 19-year-old female patient has had low haemoglobin rate of 90-95 g/l since childhood. Blood count results obtained after hospitalization are as follows: erythrocytes - 3,2 × 1012/l, Hb- 85 g/l, colour index - 0,78; leukocytes - 5,6 × 109/l, platelets - 210 × 109/l. Smear examination revealed anisocytosis, poikilocytosis and target cells. Reticulocyte rate is 6%. Iron therapy was ineffective. What blood pathology corresponds with the described clinical presentations?