Prevalence and Phenotypes of JAK2V617F and Calreticulin Mutations in a Danish General Population

There is an urgent need for more studies of the value of screening programs in individuals at high risk of having myeloproliferative neoplasms (MPNs), according to a study presented at the 12^th International Congress on Myeloproliferative Neoplasms

In this study, researchers enrolled 19,958 participants from the Danish General Suburban Population study, which was conducted from 2010-2013 and included DNA, blood tests, and questionnaires screened for JAK2V617F and CALR by a multiple droplet digital assay. They compared basic characteristics and blood tests between the mutation positive and the non-mutated population.

 Following analysis, the findings of the study showed that 3.5% of participants were mutation positive and of those, 2.5% had MPN at baseline. Also, 613 participants were JAK2V617F positive and 32 participants were CALR positive. The researchers observed that risk factors for the mutations included advanced age, smoking, and alcohol. The results also showed that JAK2V617F positives, with and without MPN, presented increased odds for prevalent venous thromboembolism. The odds ratio (OR) for a diagnosis of MPN per percentage allele burden was 1.14 (95% CI, 1.09 to 1.18). Overall, mutation positives showed higher blood cell counts juxtaposed to non-mutated with 40% of mutation positives without MPN presenting elevated blood cell counts.

“We present a novel population prevalence of the CALR and JAK2V617F mutations, being 3-30 times higher compared to less sensitive methods,” the research authors wrote. “Mutation positive non-MPNs have elevated blood cell counts which raise concerns of underdiagnosis of MPN in the population, in Denmark an estimate of 10,000 citizens with undiagnosed MPNs and accordingly 550,000 undiagnosed MPNs in US having an increased risk of life-threatening or life-invalidating blood clots in the brain, heart, lungs and elsewhere – an adding to this also carrying a 40 % increased risk of second cancer.”

Skov V, et al. Prevalence and Phenotypes of JAK2V617F and Calreticulin Mutations in a Danish General Population. Presented at the 12^th International Congress on Myeloproliferative Neoplasms; October 24-25, 2019; New York, NY.