Discrimination between iron-deficiency and heterozygous-thalassaemia syndromes in differential diagnosis of microcytosis

Lancet. 1979 Jan 20;1(8108):145-8. doi: 10.1016/s0140-6736(79)90532-4.


Three formulae have been advocated for interpreting the blood-count when differentiating between iron deficiency and heterozygous thalassaemia: the discriminant function. M.C.V.-R.B.C.-(5 X Hb)-k, the M.C.V/R.B.C. ratio, and the (M.C.V.)2 X M.C.H. product. In a comparison of their diagnostic accuracy in microcytic adults from several countries, the discriminant function was the most satisfactory. 417 of 455 uncomplicated cases (91.6%) of iron deficiency, heterozygous alpha1- and beta- thalassaemia were correctly identified. The function was not able to distinguish heterozygous alpha2-thalassaemia from iron deficiency. A flow chart illustrates how the discriminant function can be used in haematological practice.

Publication types

  • Comparative Study

MeSH terms

  • Anemia, Hypochromic / blood
  • Anemia, Hypochromic / diagnosis*
  • Diagnosis, Differential
  • Diagnostic Errors
  • Erythrocyte Count
  • Erythrocyte Volume
  • Erythrocytes, Abnormal / pathology
  • Hemoglobin A / analysis
  • Heterozygote
  • Humans
  • Thalassemia / blood
  • Thalassemia / diagnosis*
  • Thalassemia / genetics


  • Hemoglobin A