Protein S

The PROS1 gene encodes a protein which plays an important role in taming blood coagulation, so inactivating mutations bring about a higher risk of intravascular coagulation, increased risk of thrombosis. Protein S deficiency is inherited either autosomal dominant or recessive.

Epidemiology

The prevalence of protein C deficiency is 0,03-0,13%. This figure is much higher among patients with thromboembolic diseases (1-5%) and it might rise up to 15% among younger patient. In Patients with Cerebral infarctions occurring without apparent reason before age of 45 this figure is even 20%.

Gene Structure

The gene can be abreviated by PROS1. Its locus is on chromosom 3 (3p11.1-q11.2). Size is about 95kb and it consists of 15 exons.

Phenotype

Clinically important are thromboembolic diseases. Cerebral infarktion before age of 45 are suspect too. An aquired protein S deficiency must be excluded.

Pathology

The protein product is a vitamin K dependent cofactor for activated protein C. It is produced in liver, endothelial and cells.

Test Strategy

Patient with biochemical evidence of Protein S deficiency when a secondary reason is excluded. Family screening if a family member is a carrier.

Interpretation

The mutation is rare but the relative risk for thromboembolic diseases is is 8,2.

Genetests:

Related Diseases:

Autosomal recessive protein S deficiency
	PROS1

Autosomal dominant protein S deficiency
	PROS1