Hereditary protein S deficiency

EDTA Blood, 4-8 ml

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Gene list: PROS1

The gene panels are not fixed and can be adapted upon request according to the clinical indication (see test request profile 21713).

Hereditary protein S deficiency is a rare inherited blood clotting disorder associated with an increased risk of venous thrombosis and pulmonary embolism. Protein S is a vitamin K-dependent plasma protein produced in the liver. It acts as a natural anticoagulant and helps regulate blood clot formation. Reduced levels or impaired function of protein S can lead to an increased tendency to form blood clots (thrombophilia).

Three types are distinguished based on laboratory findings: type I (reduced protein S activity and reduced total and free protein S levels), type II (reduced protein S activity with normal protein S levels) and type III (reduced protein S activity with normal total protein S levels but reduced free protein S levels). Clinical manifestations vary, ranging from an absence of symptoms to recurrent thromboembolic events.

Hereditary protein S deficiency is caused by pathogenic variants in the PROS1 gene. Next-generation sequencing (NGS) is used to analyse the entire coding region of the PROS1 gene. In addition, multiplex ligation-dependent probe amplification (MLPA) is performed to detect larger deletions and duplications as well as small sequence variants identified by sequencing.