The p.P1127S pathogenic variant lowers von Willebrand factor levels through higher affinity for the macrophagic scavenger receptor LRP1: Clinical phenotype and pathogenic mechanisms.
J Thromb Haemost
; 20(8): 1818-1829, 2022 08.
Article
en En
| MEDLINE
| ID: mdl-35596664
ABSTRACT
BACKGROUND:
The index case is a 21-year-old Italian woman with a mild hemorrhagic syndrome and von Willebrand factor antigen (VWFAg) = 34.3 U/dl, VWF recombinant glycoprotein Ib (VWFGpIbR) = 32.8 U/dl, and factor VIII (FVIII) = 55.3 IU/dl.AIMS:
The aim of this study is to characterize from a genetic and biochemical standpoint this low VWF phenotype.METHODS:
Coagulation and biochemical methods were used to study the structural and functional pattern of VWF multimers in the index case's plasma. Recombinant wild-type and p.P1127S VWF variants were produced using human embryonic kidney (HEK)-293 cells. In addition, genetic screening was carried out to detect single nucleotide variants of some scavenger VWF/FVIII receptor genes such as CLEC4M, STAB2, and ASGR2.RESULTS:
Genetic investigation revealed that the index case inherited from her mother the heterozygous missense mutation c.3379C > T (VWF exon 25), causing the p.P1127S substitution in the VWF D'D3 domain. The index case was also homozygous for the scavenger receptor ASGR2 c.-95 CC-genotype. Desmopressin normalized the VWF level of the patient, although its clearance was faster (t1/2 = 6.7 h) than in normal subjects (t1/2 = 12 ± 0.7 h). FVIII-VWF interaction, A Disintegrin And Metalloprotease with ThromboSpondin type 1 motif-13 levels, ristocetin-induced-platelet-aggregation, and VWF multimeric pattern were normal. The p.P1127S variant was normally synthesized and secreted by HEK-293 cells, and molecular modeling predicts a conformational change showing higher affinity for the macrophagic scavenger receptor lipoprotein receptor-related protein 1 (LRP1), as also experimentally verified.CONCLUSIONS:
The p.P1127S variant may cause a low VWF phenotype, stemming from an increased VWF affinity for the scavenger receptor LRP1 and, consequently, an accelerated clearance of VWF.Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Enfermedades de von Willebrand
/
Factor de von Willebrand
Tipo de estudio:
Prognostic_studies
Límite:
Adult
/
Female
/
Humans
Idioma:
En
Revista:
J Thromb Haemost
Asunto de la revista:
HEMATOLOGIA
Año:
2022
Tipo del documento:
Article
País de afiliación:
Italia