A 23 year old asymptomatic female pilot has MCV-70, FERRITIN-100g/L Hb-10gm% what is the cause

Ref Harrison 19 th ed pg 638 b Thalassemia minor (i.e., thalas- semia trait) usually presents as profound microcytosis and hypochromia with tar- get cells, but only minimal or mild ane- mia. The mean corpuscular volume is rarely >75 fL; the hematocrit is rarely <30-33%. Hemoglobin analysis classically reveals an elevated HbA2 (3.5-7.5%), but some forms are associated with normal HbA2 and/or elevated HbF. Genetic counseling and patient education are essential. Patients with b thalassemia trait should be warned that their blood picture resembles iron deficiency and can be misdiagnosed.