Recurrent deletion in the human antithrombin III gene
CB Grundy, F Thomas, DS Millar, M Krawczak, E Melissari, V Lindo, E Moffat, VV Kakkar and DN Cooper
Charter Molecular Genetics Laboratory, Thrombosis Research Institute,
Chelsea, London, UK.
Eight unrelated patients with recurrent thromboembolism, a family history
of thrombosis, and plasma antithrombin III (ATIII) activity/antigen levels
consistent with a diagnosis of heterozygous type I ATIII deficiency were
studied by polymerase chain reaction/direct sequencing of ATIII gene
exon-coding regions. Frameshift mutations of one base and two bases,
respectively, were found to have occurred in two unrelated patients at the
same GAG codon (Glu 245) within exon 4 of the ATIII gene. A literature
search showed six further hitherto unrecognized deletion "hotspots" in four
other human genes. These deletion-prone sites exhibited sufficient sequence
homology with each other to derive a consensus sequence (T G A/G A/G G
A/C), suggesting that deletion in human genes may not only be non- random
but also sequence-directed.
Volume 78,
Issue 4,
pp. 1027-1032,
08/15/1991
Copyright © 1991 by The American Society of Hematology