Abstract
Newborns with trisomy 13 have elevated hemoglobin (HB) F; those with trisomy 21 have increased HB A. To examine this “switch”, blood was obtained from neonates, incubated with 3H-leucine, and globin chains separated on carboxymethylcellulose columns in urea:
β/α ratios were in the range of β-thal trait in trisomy 13, and in 4/6 with trisomy 18. (β+γ)/α was also low. β/α was above normal in 2/6 with trisomy 18, and in trisomy 21. (β+γ)/α was high. Thus the high HB F in trisomy 13 results from normal γ/α synthesis, but a delay in turning on β chain. High HB A in trisomy 21 is due to an early and coordinated switch from γ to β synthesis. Trisomy 18 infants represent both types. Finally these data emphasize that abnormalities other than thal genes may lead to aberrant β/α ratios in neonates and also may affect the β/γ ratios in utero that are used to define hemoglobin phenotypes in prenatal diagnoses.
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Alter, B., Beaudet, A. & Scott, C. 504 REGULATION OF GLOBIN CHAIN SYNTHESIS IN NEONATES. Pediatr Res 12 (Suppl 4), 447 (1978). https://doi.org/10.1203/00006450-197804001-00509
Issue Date:
DOI: https://doi.org/10.1203/00006450-197804001-00509