prevalence of minor β-thalassemia based on rbc indices among final suspected individuals in premarital screening program referred to genetic laboratories

introduction: the current study evaluated the value of red blood cell (rbc) indices and the corresponding cut- off points for β-thalassemia control programs in iran. materials and methods: 1,150 individuals (575 couples) with low rbc indices and normal hemoglobin a2 who had been referred to the genetic centre of isfahan, were tested during pre-marital screening analyses, in the 2 year period, 2006-2008. β-thalassemia mutations were evaluated. results: β-thalassemia was identified in 67.8% of the cases with both mean corpuscular volume (mcv) less than 78fl and mean corpuscular hemoglobin (mch) less than 26 pg. however, 4.1% of the individuals with  78≤ mcv≤ 80 tested positive for thalassemia. mcv showed a higher diagnostic reliability than mch. however, the accompaniment of mch<26 with mcv<78 increased the risk of thalassemia 35 times. a significant association was found between the prevalence of minor β-thalassemia and educational levels, race and familial relationships. conclusion: according to the results of this study, it seems that mcv=80fl can be used as a proper cut- off point for the screening of minor β-thalassemia. although in the present study mcv was found to have a higher diagnostic reliability than mch, mch <26 along with mcv are very helpful indices for the counselor physician to estimate the risk of minor β-thalassemia more accurately.