A 15-year-old male patient has had anemia and jaundice for 5 years, with a spleen palpable 2.5 cm below the costal margin. Hb is 75 g/L, reticulocytes 0.06, and normal white blood cell (WBC) and platelet (PLT) counts. Bone marrow shows marked hyperplasia with erythroid predominance. Red cell osmotic fragility test reveals hemolysis initiation in 0.70% saline solution. His father also has mild anemia and jaundice. The most likely diagnosis is: