Hi Farjana,
You are not a beta thal minor. You are a hemoglobin E (HbE) carrier. This is extremely common in Bangladesh. Your electrophoresis results would be very different if you also carried beta thal. However, if the electrophoresis is accurate, you may also be an alpha thalassemia carrier. A repeat of the hemoglobin electrophoresis could verify this. Normally, an HbE carrier will show at least 30% HbE, unless alpha thal carrier status is also present. Alpha thal trait and HbE are also commonly found in the same areas of the world, making it more likely that this is possible. Iron deficiency can also lower the HbE percentage, but you did not respond to iron therapy, so this leaves things somewhat clouded. A panel of tests called iron studies would measure ferritin but also other indicators of iron status, so it may be advisable to have this done first, to make sure it is not iron deficiency. If iron deficiency can be totally ruled out, then it may be necessary to look at your alpha gene status, which can only be done through a DNA analysis. While some alpha deletions will reduce the severity of HbE anemia, triplicated or quadruplicated {alpha}-globin genes increase the severity of E-thalassemia. Normally, HbE carriers have no symptoms at all, so it does appear that there may be more than HbE at work here. My suggestion would be the iron panel and then a DNA analysis, if possible. I am not certain this can be done in Bangaldesh, but if necessary, I can contact Dr Robin in Dhaka about this.