|
|||||||||
|
|
|
|
|
|
|
|
|
|
|
Prepublished online as a Blood First Edition Paper on February 20, 2003; DOI 10.1182/blood-2002-11-3391.
Blood, 1 August 2003, Vol. 102, No. 3, pp. 919-925 Antithrombin Phe229Leu: a new homozygous variant leading to spontaneous antithrombin polymerization in vivo associated with severe childhood thrombosisFrom the Service d'Hématologie Biologique A, Hôpital Européen Georges Pompidou, Paris; France; the Laboratoire d'Hématologie, Faculté de Pharmacie, Université Paris XI, Châtenay-Malabry, Paris, France; the Laboratoire d'Hématologie, Hôpital Necker-Enfants Malades, Paris, France; Institut National de la Santé et de la Recherche Médicale (INSERM) Unité 428, Faculté de Pharmacie, Université Paris V, Paris, France; and the Département d'anesthésie-réanimation, Hôpital Necker-Enfants Malades, Paris, France
There is increasing evidence that serpin conformational alteration caused by single point mutations can be responsible for protein deficiency associated with human diseases. A typical example is the
This article has been cited by other articles:
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 |
 |
 |
|||||||
 |
 |
 |
 |
 |
 |
 |
 |
||
| Copyright © 2003 by American Society of Hematology Online ISSN: 1528-0020 | |||||||||
1-antitrypsin deficiency caused by the Z variant carrying a Glu342Lys substitution. Only a few cases of "conformational disease" involving other serpins have been described so far. We investigated a severe antithrombin deficiency in a 13-month-old child with fever and cerebral venous thrombosis. The infant was found to be homozygous for a new antithrombin gene mutation (7396T>C, predicting a Phe229Leu antithrombin variant), and heterozygous for the factor V Leiden mutation. Mild atypical antithrombin deficiency was found in both parents, who were first cousins, asymptomatic, and heterozygous for the same antithrombin gene mutation. The Phe229Leu variant, which does not readily fit into the current classification of antithrombin deficiency, was shown to be a thermolabile antithrombin that spontaneously polymerized in the proband's circulation. This points to a key role for the conserved Phe at position 229, which is near the reactive site loop in a region critical for serpin function and stability. Molecular modeling suggested how the mutation might destabilize this region of the protein and thereby favor reactive site loop insertion and polymerization. This study provides the first direct evidence of antithrombin polymerization in vivo causing antithrombin deficiency and severe thrombotic disease. 
