Hemoglobin content of single erythrocytes from fetuses with parents having heterozygous beta-thalassemia.

The hemoglobin content of single erythrocytes was determined by microspectrophotometry as total extinction (TE) at 415 nm in subjects with a wide spectrum of hemoglobin levels and erythrocyte indices. Precise measurements of the cellular area (A) and the ratio TE/A were also recorded. A significant correlation was found between TE and mean corpuscular hemoglobin (MCH), A and mean corpuscular volume, and TE/A and mean cell hemoglobin concentration (MCHC) for the cases studied. In addition, TE, A and TE/A were determined in fetal erythrocytes obtained by fetoscopy at the 20th week of gestation for prenatal diagnosis of beta-thalassemia. The mean red cell TE and TE/A of the group of fetuses diagnosed to have thalassemia major were significantly lower than those of the group of normal controls and with heterozygous beta-thalassemia. The significant differences of TE, A and TE/A between maternal and fetal blood allowed a safe distinction of the latter. The calculated MCH of the fetuses with thalassemia major was 12% less than that of the normal controls; the respective difference of the mean cell size was 5% and that of MCHC 3% lower than normal.

Selective survival of only the healthy fetus following prenatal diagnosis of thalassaemia major in binovular twin gestation.

Selective feticide is the procedure of choice when, in twin binovular pregnancy, only one of the fetuses is shown to be affected. As the probabilities for this condition are almost 1:2 when the genetic disease is due to homozygosity for two autosomal recessive genes, the problem is expected to occur frequently among the ever increasing number of couples seeking prenatal diagnosis of thalassaemia and the haemoglobinopathies. The present report is the first case of this condition and the ninth in the overall medical literature.

Prenatal diagnosis of thalassaemia by haemoglobin chromatography on Biorex. An evaluation of the method.

The applicability of the chromatographic separation of haemoglobin F, A and S on Biorex 70 ( Blouquit et al., 1982) for the prenatal diagnosis of thalassaemia and related conditions was evaluated in comparison to the conventional globin chain separation technique. The method proved reliable, inexpensive and rapid and should be considered as a valuable alternative in laboratories carrying out great numbers of tests and those being newly set up for this purpose.