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The 32·6 kb Indian δβ‐thalassaemia deletion ends in a 3·4 kb L1 element downstream of the β‐globin gene
Author(s) -
Gilman J. G.,
Brinson E. C.,
Mishima N.
Publication year - 1992
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1111/j.1365-2141.1992.tb06439.x
Subject(s) - breakpoint , biology , gene , genetics , microbiology and biotechnology , enhancer , genbank , globin , chromosome , gene expression
S ummary . The Indian δβ‐thalassaemia, with elevated fetal γ globin gene expression, was previously found to have a large deletion beginning 1 kb 3’of the A γ globin gene at GenBank HUMHBB coordinate 42151, and extending into a new L1 sequence. We have now determined the 3’breakpoint of this deletion, and in doing so we have extended the known β‐globin gene cluster DNA sequence from its end at 73326 to projected GenBank coordinate 79016. These data show that the deletion is 32–6 kb long, terminating 11 kb 3’of the β‐globin gene. This 3’breakpoint is at 74772, within a 3.4 kb partial L1 repeat at 74263–77665; the Black ( A γδβ)°‐thalassaemia also terminates in this L1, at 76508. In addition, two Alu sequences were found, at 73692–73816 and 78171–78441. Among the protein‐binding DNA sequence motifs 3’to the Indian δβ‐thalassaemia breakpoint, at 76581/76607 there is a TGATAA/ACACCC pair that binds the erythroid‐specific GATA‐1 and ubiquitous CACCC‐box binding proteins. We hypothesize that elevated fetal haemoglobin may be due to an enhancer or enhancers 3’to the deletion breakpoints and may involve the TGATAA/ ACACCC pair.