Congenital Thrombotic Thrombocytopenic Purpura (TTP)

 

Chromosome: 9q34

Gene affected: ADAMTS13

Protein affected: von Willebrand Factor (vWF) cleaving protease (VWFCP)

 

Inheritance may be autosomal recessive.

 

Clinical features:

(1) The onset of symptoms may be during childhood or as an adult.

(2) The patient experiences episodes of microangiopathic anemia with thrombocytopenia, fever, renal dysfunction and neurologic dysfunction.

(3) An episode may be triggered by a physiologic stress such as infection or pregnancy.

(4) Plasma shows a deficiency in von Willebrand factor cleaving protease (VWFCP) activity.

(5) The patient responds to infusions of fresh frozen plasma (which provides VWFCP)

 

Diagnosis requires exclusion of other causes of TTP.

 

Upshaw-Schulman Syndrome (USS) is a type of congenital TTP discussed in the next section.