Camilleri, Raymond, Cohen, H., Mackie, I.J., Skully, M., Starke, R.D., Crawley, J.T., Lane, D.A. and Machin, S.J. (2008) Prevalence of the ADAMTS-13 missense mutation R1060W in late onset adult thrombotic thrombocytopenic purpura. Journal of Thrombosis and Haemostasis, 6 (2). pp. 331-338. ISSN 1538-7933Full text not available from this repository.
Background: Thrombotic thrombocytopenic purpura (TTP) is most commonly associated with deficiency or inhibition of von Willebrand factor-cleaving protease (ADAMTS-13) activity. ADAMTS-13 mutations and polymorphisms have been reported in childhood congenital TTP, but their significance in adult onset TTP remains unclear. Objectives: We sought to identify common ADAMTS-13 mutations in adults with late onset TTP and to investigate whether they may predispose acute clinical episodes of the disorder in adulthood. Patients/Methods/Results: We detected a missense mutation (C3178T) in exon 24 of ADAMTS-13 in 6/53 (11.3%) adult onset TTP patients, but no normal controls (n = 100). Three of the patients had pregnancy-associated TTP; three had chronic relapsing acute idiopathic TTP. C3178T encodes an arginine to tryptophan (R1060W) substitution in the TSP1-7 domain of ADAMTS-13. In vitro expression of mutant and wild-type ADAMTS-13 demonstrated that R1060W caused severe intracellular retention of ADAMTS-13 (<5% secretion) without affecting its metalloprotease activity. One homozygous and five heterozygous patients were identified. No other causative mutations were discovered, yet all six patients had ADAMTS-13 activity levels <5% at presentation (normal: 66–126%). Antibodies/inhibitors to ADAMTS-13 were detected in three/five heterozygous patients, and all six patients had subnormal antigen levels. Six asymptomatic first-degree relatives, including those of two probands with antibodies, were also heterozygous for C3178T; all but one had subnormal ADAMTS-13 activity. Conclusion: The high prevalence of R1060W ADAMTS-13 in adult onset TTP, together with its absence in childhood congenital TTP cases reported elsewhere, suggests it may be a factor in the development of late onset TTP.
|Subjects:||University of Westminster > Science and Technology > Life Sciences, School of (No longer in use)|
|Depositing User:||Miss Nina Watts|
|Date Deposited:||15 Jun 2011 15:01|
|Last Modified:||15 Jun 2011 15:01|
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