Nonrandom distribution of genotypes among red cell indices.

Venous blood samples were obtained from 25,302 healthy adults in Kentucky, USA. The red cell indices measured on these samples were evaluated by multiple stepwise regression analysis to derive an algorithm capable of discriminating the 138 individuals within this population who had genotypes AA, AC, AS or AA beta-thalassemia. The simple discriminant MCV2 x MCH with a cut-off set at 1530 detected 137 out of 138 of the heterozygotes with a false positive rate in this population of 4.

A strategy to detect beta-thalassaemia minor.

Over the past three years 25 302 adults in Kentucky have been tested for haemoglobinopathies, and of these, haemoglobin A2 was measured on 3734, 1973 with microcytosis and 1761 within the normal range. The best methods of detecting beta-thalassaemia minor using red-blood-cell indices were compared. No method detected all heterozygotes.