Prothrombin gene 20209 C >T along with the first description of a homozygous polymorphism at the 3' downstream region +4 C >T in the Turkish population.

Mutation screening studies related with thrombosis revealed that prothrombin 20210A allele of the prothrombin gene leads to an increase in plasma prothrombin levels. The G20210A mutation screening has become a routine analysis in patients with thrombosis. For the detection of the mutation, several molecular techniques have been defined. Real-time polymerase chain reaction is an easy and feasible way to monitor this mutation according to the melting point analysis. Here we report a different pattern in the LightCycler melting point analysis of 2 patients with thrombosis. DNA sequencing of the prothrombin gene showed that these patients with an atypical melting point profile carry a 20209 C >T mutation along with a novel homozygous polymorphism at the 3' downstream region, +4 C >T.