Genomic classification and outcomes of young patients with polycythemia vera and essential thrombocythemia according to the presence of splanchnic vein thrombosis and its chronology.

"Declarations Ethical approvalThe study was conducted in accordance with the Declaration of Helsinki and approved by the Institutional Review Board of Hospital Clínic de Barcelona (HCB/2019/155, January 11th 2019 and HCB/2022/0945, November 10th 2022). Signed informed consent according review board requirements was obtained from all participants. Conflict of interestJCGP is a consultant for COOK and has received a research grant from GORE. DC has received honoraria from AbbVie, AstraZeneca, Incyte, Novartis and Thermofisher for speaking at education activities. AAL is a consultant and has received honoraria from AOP for speaking at education activities. The other authors do not have competing interests to declare. Conflict of interest JCGP is a consultant for COOK and has received a research grant from GORE. DC has received honoraria from AbbVie, AstraZeneca, Incyte, Novartis and Thermofisher for speaking at education activities. AAL is a consultant and has received honoraria from AOP for speaking at education activities. The other authors do not have competing interests to declare."

"Funding Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature."