BACKGROUND & AIMS: Extrahepatic portal vein thrombosis and Budd-Chiari syndrome frequently result from multiple concurrent factors such as cirrhosis, intra-abdominal sepsis, procoagulant states, and underlying myeloproliferative disorders (MPDs). The JAK2 V617F mutation is a point mutation in the Janus kinase 2 (JAK2) tyrosine kinase that is variably present in MPDs. The incidence depends on the subclassification of the MPDs and the sensitivity of the assay used. This case series aimed to illustrate the diagnostic utility of JAK2 V617F mutation in atypical cases of MPD that otherwise may not have met traditional diagnostic criteria. METHODS: Granulocytic DNA was obtained and real-time polymerase chain reaction was performed using allele-specific primer and probe to provide a quantitative expression of the V617F mutation. RESULTS: The JAK2 V617F point mutation was found in 3 patients with extrahepatic portal vein thrombosis who had multiple thrombotic events but did not fulfill the traditional diagnostic criteria for MPDs. CONCLUSIONS: A sensitive assay for the JAK2 V617F mutation has the potential to diagnose atypical MPDs in multiple undiagnosed cases of intra-abdominal thrombosis and therefore alter the management and prognosis of these patients.
BACKGROUND & AIMS: Extrahepatic portal vein thrombosis and Budd-Chiari syndrome frequently result from multiple concurrent factors such as cirrhosis, intra-abdominal sepsis, procoagulant states, and underlying myeloproliferative disorders (MPDs). The JAK2 V617F mutation is a point mutation in the Janus kinase 2 (JAK2) tyrosine kinase that is variably present in MPDs. The incidence depends on the subclassification of the MPDs and the sensitivity of the assay used. This case series aimed to illustrate the diagnostic utility of JAK2 V617F mutation in atypical cases of MPD that otherwise may not have met traditional diagnostic criteria. METHODS: Granulocytic DNA was obtained and real-time polymerase chain reaction was performed using allele-specific primer and probe to provide a quantitative expression of the V617F mutation. RESULTS: The JAK2 V617F point mutation was found in 3 patients with extrahepatic portal vein thrombosis who had multiple thrombotic events but did not fulfill the traditional diagnostic criteria for MPDs. CONCLUSIONS: A sensitive assay for the JAK2 V617F mutation has the potential to diagnose atypical MPDs in multiple undiagnosed cases of intra-abdominal thrombosis and therefore alter the management and prognosis of these patients.