Abstract
Antenatal diagnosis of β-thal depends on safe acquisition of fetal RBC and detectability of β-thal in midtrimester. To approach these requirements, a normal nomogram of the β/γ globin chain synthetic ratio in fetal RBC obtained at hysterotomy was derived by incubation of the cells with 3H-leucine followed by urea-CMC radiochromatography. This revealed that the β/γ ratio increases from 0.075 ± 0.02 at 6 wks to 0.09 ± 0.02 at 16 wks of gestation. Secondly, globin chain synthesis was measured in fetal EBC collected in utero with a 2.7 mm aspiration fetoscope from midtrimester chorionic plate vessels of 4 normal women by the methods of Hobbins and Mahoney. All samples gave normal β/γ ratios for gestational age. Finally, to detect the presence of β-thal in the first trimester, fetal blood from vacuum-extracted abortuses of 3 Cypriot women, 2 of whom had β-thalassemia trait, was examined by similar methods which also included subtraction of β chain radioactivity contributed by contaminating maternal RBC. In 1 fetus of a β-thalassemia trait mother, the β/γ ratio was 0.04 at 10 ½ wks, a 50% reduction consistent with fetal β-thalassemia trait. The others were normal. These results suggest that fetal cells can be acquired at midtrimester and that β-thal may be detected as early as the first trimester; hence, the antenatal diagnosis of β-thal is becoming a biological and technical reality.
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Chang, H., Modell, C., Huehns, E. et al. ANTENATAL DIAGNOSIS OF THE β-THALASSEMIA GENE (β-thal). Pediatr Res 8, 398 (1974). https://doi.org/10.1203/00006450-197404000-00349
Issue Date:
DOI: https://doi.org/10.1203/00006450-197404000-00349