GENETIC ANALYSIS BY MULTIPLEX LIGATION-DEPENDENT PROBE AMPLIFICATION IN PROTEIN S DEFICIENCY

Abstract number: O-T-089

Garcia¹ A.A., Borgel² D., Alhenc-Gelas² M., Spek³ C., Gandrille² S., Reitsma¹ P.H.

¹¹Experimental Vascular Medicine, Leiden University Medical Center, Leiden, Netherlands ²²Service d'Hématologie Biologique A, Faculté des Sciences Pharmaceutiques et Biologiques, Paris, France ³³Center for Experimental and Molecular Medicine, Academic Medical Center, Amsterdam, Netherlands

How-to-cite Garcia AA, Borgel D, Alhenc-Gelas M, Spek C, Gandrille S, Reitsma PH. GENETIC ANALYSIS BY MULTIPLEX LIGATION-DEPENDENT PROBE AMPLIFICATION IN PROTEIN S DEFICIENCY. J Thromb Haemost 2007; 5 Supplement 2: O-T-089

Abstract

Introduction: Hereditary deficiency of Protein S (PS) is an autosomal disorder linked to the PS gene (PROS1). Conventional mutation detection techniques identify PROS1 point mutations in approximately 50% of the PS deficiencies. In order to verify the suggestion that gross gene abnormalities are often present in the remaining 50% of patients we used multiplex ligation-dependent probe amplification (MLPA).

Methods: DNA from 14 PS-deficient families, in which PROS1 mutations were not found by exon targeted DNA sequencing, was evaluated by MLPA, a PCR-based technique which allows exon copy number detection in genomic DNA. A commercial MLPA kit was used that contains probes for 12 out of the 15 PROS1 exons, 1 probe for a region just upstream of the PROS1 promoter, 1 probe for the PS pseudogene and 16 control probes. Deletions of probe recognition sequences will be apparent by a 35-50% reduced relative peak area of the amplification product of that probe.

Results: Complete deletion of PROS1 was detected in 3 families where the MLPA analysis of the exons showed a decrease of around 50% in the relative peak areas (heterozygous pattern in MLPA analysis) in comparison with the control probes. Two families presented a partial deletion involving different parts of the gene (one with deletion from exon 4 until 9 and another one with deletion between exon 9 and 11). There is apparent partial gene duplication in one family, in which exons 4-11 of the PROS1, showed a 2-fold increase in relative peak area

Conclusions: This study confirms that gross gene abnormalities in PROS1 are relatively common in PS deficient patients and that MLPA seems to be a useful tool in direct screening for copy number changes in PROS1 point mutation-negative individuals

To cite this abstract use the following format:

Journal of Thrombosis and Haemostasis 2007; Volume 5, Supplement 2: abstract number

Session Details

Date:	01/08/2007
Time:	00:00-00:00
Session name:	XXIst ISTH Congress
Subject:
Location:	Oxford, UK
Presentation type:
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