Thromb Haemost 1985; 53(03): 314-319
DOI: 10.1055/s-0038-1661305
Original Article
Schattauer GmbH Stuttgart

Antithrombin III “Northwick Park”: A Variant Antithrombin with Normal Affinity for Heparin but Reduced Heparin Cofactor Activity

D J Howarth
The M.R.C. Epidemiology and Medical Care Unit, Northwick Park Hospital, Harrow, UK
,
Diana Samson
1   The Department of Haematology, Northwick Park Hospital, Harrow, UK
The M.R.C. Epidemiology and Medical Care Unit, Northwick Park Hospital, Harrow, UK
,
Yvonne Stirling
The M.R.C. Epidemiology and Medical Care Unit, Northwick Park Hospital, Harrow, UK
,
M J Seghatchian
The M.R.C. Epidemiology and Medical Care Unit, Northwick Park Hospital, Harrow, UK
› Institutsangaben
Weitere Informationen

Publikationsverlauf

Received 07. Juli 1984

Accepted 19. Februar 1985

Publikationsdatum:
18. Juli 2018 (online)

Preview

Summary

Further studies have been carried out in a previously reported family with congenital antithrombin III (AT III) deficiency due to an abnormal variant of AT III (AT III Northwick Park). The variant has been identified in five members of the family, three of whom had a history of venous thrombosis. Inheritance followed an autosomal dominant pattern. The affected family members have reduced levels of antithrombin heparin cofactor (41–67%) and progressive antithrombin activity (44–62%) but normal levels of immunoreactive AT III (91–162%). Two dimensional immunoelectrophoresis (2 DIE) of AT III in the absence of heparin revealed an abnormal fast-moving peak in addition to the normal peak but 2 DIE in the presence of heparin appeared normal. Further studies confirmed that the abnormal AT III binds completely to heparin but has no heparin cofactor or progressive antithrombin activity. These results would be consistent with a mutation affecting the binding site for thrombin.