Aim: Janus kinase 2 (JAK2) V617F mutation testing has revolutionized the classification of myeloproliferative disorders, for which several tests have been introduced for qualitative and quantitative diagnostics including the MutaScreen and MutaQuant kits by IPSOGEN. One interesting technical observation are those values detected by MutaScreen kits, which have typically "indeterminate" meaning at a provided reference strand cutoff point and cannot be classified as either positive or negative for JAK2 V617F mutation.
Results: We ran 10 different patients with such a finding using the MutaQuant kit and got a better resolution and interpretation into clear-cut negative or positive cases, which were also clinically followed and confirmed as being nonmyeloproliferative or myeloproliferative entities, respectively.
Conclusion: We propose that it is important to not consider the indeterminate or "at-the-reference strand" results obtained by MutaScreen as positive but rather perform additional testing using MutaQuant kits or other JAK2 quantitative assays. For laboratories that can afford it and utilize both assays, it may be a better strategy to directly initiate diagnostic testing using the MutaQuant rather than the MutaScreen kit.