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
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
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