Autosomal recessive protein S deficiency is caused by mutations of the PROS1 gene. In contrast to the dominantly inherited form the mutations are not so severe such that a residual function may persist, and only if two alleles are affected a typical thrombophilia phenotype develops. Heterozygous carriers of those mutations usually have about 50% of the normal protein S activity.
Clinical chemistry allows to distinguish three types of protein S deficiency: Type 1: The protein is reduced in plasma. Type 2: The protein concentration in plasma is normal but its activity reduced. Type 3: The concentration of the free protein is reduced and this leads to a reduced plasma activity. Occasionally, a combination of type 3 and 1 or 2 can exist in one patient. The combination 1/3 is most common.[Error: Macro 'ref' doesn't exist]
When measuring plasma concentration, warfarin and other vitamin K antagonists have to be discontinued sufficiently enough.
1. |
Espinosa-Parrilla Y et al. (1999) Protein S gene analysis reveals the presence of a cosegregating mutation in most pedigrees with type I but not type III PS deficiency. |
2. |
Pung-amritt P et al. (1999) Compound heterozygosity for one novel and one recurrent mutation in a Thai patient with severe protein S deficiency. |
3. |
Mintz-Hittner HA et al. (1999) Vitreoretinal findings similar to retinopathy of prematurity in infants with compound heterozygous protein S deficiency. |
4. |
Fischer D et al. (2010) Intracerebral mass bleeding in a term neonate: manifestation of hereditary protein S deficiency with a new mutation in the PROS1 gene. |
5. |
Mahasandana C et al. (1990) Homozygous protein S deficiency in an infant with purpura fulminans. |
6. |
Kamiya T et al. (1986) Inherited deficiency of protein S in a Japanese family with recurrent venous thrombosis: a study of three generations. |
7. |
Comp PC et al. (1984) Familial protein S deficiency is associated with recurrent thrombosis. |
8. |
Bosson JL et al. (1995) [Venous thromboembolic disease in children related to transient protein S deficiency following varicella]. |
9. |
OMIM.ORG article Omim 614514 |