Hydrops Fetalis Caused by α-Thalassemia: An Emerging Health Care Problem

PCR-based diagnosis of the Filipino (--(FIL)) and Thai (--(THAI)) alpha-thalassemia-1 deletions

In southeast Asia, the carrier frequency of two-gene alpha-thalassemia deletions is quite high, ranging from 4% to 14% depending on the population. The most common alpha-thalassemia-1 deletion is the so-called southeast Asian deletion (--(SEA)). In addition, a significant proportion of cases involve two other deletions, the Filipino (--(FIL)) and Thai (--(THAI)) deletions. In this report, we identify the deletion breakpoints for the (--(FIL)) and (--(THAI)) deletions, and describe PCR-based protocols for rapid and reliable DNA diagnosis of these deletions.

Reversal of Lethal - and β-Thalassemias in Mice by Expression of Human Embryonic Globins

Genetic mutations that block - or β-globin gene expression in humans can result in severe and frequently lethal thalassemic phenotypes. Homozygous inactivation of the endogenous - or β-globin genes in mice results in corresponding thalassemic syndromes that are uniformly fatal in utero. In the current study, we show that the viability of these mice can be rescued by expression of human embryonic ζ- and -globins, respectively. The capacity of embryonic globins to fully substitute for their adult globin homologues is further demonstrated by showing that ζ- and -globins reverse the hemolytic anemia and abnormal erythrocyte morphology of mice with nonlethal forms of - and β-thalassemia. These results illustrate the potential therapeutic utility of embryonic globins as substitutes for deficient adult globins in thalassemic individuals. Moreover, the capacity of embryonic globins to functionally replace their adult homologues brings into question the physiologic basis for globin gene switching.

© 1998 by The American Society of Hematology.

Reversal of Lethal - and β-Thalassemias in Mice by Expression of Human Embryonic Globins

Genetic mutations that block - or β-globin gene expression in humans can result in severe and frequently lethal thalassemic phenotypes. Homozygous inactivation of the endogenous - or β-globin genes in mice results in corresponding thalassemic syndromes that are uniformly fatal in utero. In the current study, we show that the viability of these mice can be rescued by expression of human embryonic ζ- and -globins, respectively. The capacity of embryonic globins to fully substitute for their adult globin homologues is further demonstrated by showing that ζ- and -globins reverse the hemolytic anemia and abnormal erythrocyte morphology of mice with nonlethal forms of - and β-thalassemia. These results illustrate the potential therapeutic utility of embryonic globins as substitutes for deficient adult globins in thalassemic individuals. Moreover, the capacity of embryonic globins to functionally replace their adult homologues brings into question the physiologic basis for globin gene switching.

© 1998 by The American Society of Hematology.