Prevalence of alpha thalassemia in microcytic anemia: a tertiary care experience from north India

Cases with microcytosis not responding adequately to iron supplementation are diagnostic dilemma and have been reported to harbor alpha (α) thalassemia mutations. The aim of this study was to determine the common α globin gene deletions in cases with microcytic anemia.

Fifty four patients selected (22 females and 32 males) had microcytic anemia (MCV < 80 fl, Hb <12gm/dl) with raised TRBC (> 5M/mm3) but normal Hb HPLC. They had either low or normal Transferrin Saturation (TS). Gap-PCR for four common α-gene deletions (-α(3.7), -α(4.2), - -α(SA) and --α(SEA)) was done.

Out of the total fifty-four cases nineteen (35.2%) cases were found to have α gene mutations; Three homozygous and sixteen heterozygous cases including -α(3.7) deletions and a single case of -- α (SA) ; but no -α(4.2) and -(SEA) mutations were found.

α gene mutations can confound iron deficiency anemia, but no RBC indices, or a discriminant function can identify it is presence Molecular studies have to be resorted to. Gap PCR for common α thalassemia mutation including -α (SA) should be done even in the face of low iron stores in subjects who respond incompletely to iron supplementation.