ISSN:
1420-9071
Keywords:
In vivo
;
cistron
;
thalassemia
;
heterozygotes
;
enhancer
;
locus control region
;
in cis
;
in trans
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract There is considerable evidence suggesting that the switch from γ to δ and β chain production after birth is due, in part, to silencing of the γ genes by stage-specific factors which bind to their promoters and to the competition from the adult (δ and β) genes for a common enhancer element located in the locus control region. As a consequence one can expect that the increased Hb F production in adults with hereditary persistence of fetal hemoglobin or δβ-thalassemia is directed mainly by γ-globin genes in cis to the deletion(s) responsible for these conditions. Here we review data on heterozygotes with γ-, δ-, or δβ-thalassemia, who also had anAγT mutation, in cis or in trans, which was used as a marker of γ gene expression. The results show that a deletion affecting adult β genes favors the expression of γ genes in cis, while the deletion of a single γ gene does not affect the expression of the β gene in cis but leads to a faster γ→β switch postnatally.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01984958
