Thromb Haemost 1996; 76(04): 505-509
DOI: 10.1055/s-0038-1650612
Original Article
Schattauer GmbH Stuttgart

A Heparin Cofactor II Mutation (HCII Rimini) Combined with Factor V Leiden or Type I Protein C Deficiency in Two Unrelated Thrombophilic Subjects

F Bernardi
Dipartimento di Biochimica e Biologia Molecolare, Centro di Studi Biochimici delle Patologie del Genoma Umano, Universita di Ferrara, Ferrrara
,
C Legnani
1   Divisione di Angiologia e Malattie della Coagulazione, Policlinico S. Orsola-Malpighi, Bologna, Italy
,
F Micheletti
Dipartimento di Biochimica e Biologia Molecolare, Centro di Studi Biochimici delle Patologie del Genoma Umano, Universita di Ferrara, Ferrrara
,
B Lunghi
Dipartimento di Biochimica e Biologia Molecolare, Centro di Studi Biochimici delle Patologie del Genoma Umano, Universita di Ferrara, Ferrrara
,
P Ferraresi
Dipartimento di Biochimica e Biologia Molecolare, Centro di Studi Biochimici delle Patologie del Genoma Umano, Universita di Ferrara, Ferrrara
,
G Palareti
1   Divisione di Angiologia e Malattie della Coagulazione, Policlinico S. Orsola-Malpighi, Bologna, Italy
,
R Biagi
1   Divisione di Angiologia e Malattie della Coagulazione, Policlinico S. Orsola-Malpighi, Bologna, Italy
,
G Marchetti
Dipartimento di Biochimica e Biologia Molecolare, Centro di Studi Biochimici delle Patologie del Genoma Umano, Universita di Ferrara, Ferrrara
› Author Affiliations
Further Information

Publication History

Received 28 February 1996

Accepted after resubmission 26 June 1996

Publication Date:
10 July 2018 (online)

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Summary

305 patients with juvenile thromboembolic episodes were screened for the presence of heparin cofactor II deficiency. The heterozygous deletion of two bases was found in the exon 5 of the heparin cofactor II gene in two unrelated patients, very likely due to a founder effect. This molecular lesion, causing a frameshift and elongated translation, affects the core of the molecule and should cause the complete unfolding of the protein, which is in accordance with the observed type I deficiency. The corresponding region of antithrombin III gene is affected by a cluster of frameshift mutations suggesting that heparin cofactor II and antithrombin III could share similar mutational patterns.

The heparin cofactor II gene alteration was associated with, in one patient, the factor V Leiden mutation and, in the other, type I protein C deficiency. The tracing of the single defects in several family members indicated that the mutations became clinically manifest only when present in the doubly heterozygous condition. This study provides two examples, based on molecular findings, of the interplay of risk factors which is potentially useful to define a role for heparin cofactor II deficiency in inherited thrombophilia.