Learning how to make a diagnosis of alpha thalassemia
A 29 year old Taiwanese man, working as a painter, underwent a routine health check up. He was found to have microcytic blood indices on a complete blood count. He had no prior significant symptoms and had never visited the hospital ever before. On questioning further, he did mention that his father and his younger sibling both had similar microcytic blood indices, but they too remained asymptomatic like him. His physical examination was normal and showed no pallor or any significant organomegaly. His blood counts revealed a Hb 13.7 g/dl, Hct 43%, MCV 69.fl, MCH 21.7 pg and MCHC 31.6 g/dl, and a RBC of 6.28 million/ul. As part of microcytic anemia, his serum ferritin levels were done and was found to be normal. (Serum Ferritin is 80 ng/ml). The peripheral smear just showed some microcytic red blood cells. There was no evidence of any basophillic stippling. A hemoglobin electrophoresis done as a part of work up for microcytosis done shows the following reports - Hemoglobin A 96.8%, Hemoglobin F - 1% and hemoglobin A2 2.0%
What is the most likely diagnosis?