Submitted April 5, 2006
Accepted June 30, 2006
Pediatric patients with essential thrombocythemia are mostly polyclonal and V617FJAK2 negative
Maria L Randi*, Maria C Putti, Margherita Scapin, Enrica Pacquola, Fabio Tucci, Concetta Micalizzi, Luigi Zanesco, and Fabrizio Fabris
Dept. of Medical and Surgical Sciences, Internal Medicine, University of Padua
Dept of Pediatrics, Pediatric Hematology-Oncology, Univeristy of Padua
Dept of Medicial and Surgical Sciences, Internal Medicine, University of Padua
Dept of Medical and Surgical Sciences, Internal Medicine, University of Padua
Pediatric Clinic, Meyer Hospital, Florence
Dept. Pediatric Hematology-Oncology, Genova
Dept of Pediatrics, Pediatric Hematology-Oncology, University of Padua
* Corresponding author; email: marialuigia.randi{at}unipd.it.
Essential thrombocythemia (ET) is rare in children and little or no information is available about clonality or JAK2 mutation. These analyses prove useful, however, for the diagnosis of adults myeloproliferative disorders (MPD). We evaluated the clonality status and V617FJAK2 mutation in 20 children affected by ET and compared them with 47 consecutive adult ET. Clonality was evaluated on the DNA of granulocytes and on the RNA of platelets. V617FJAK2 was analyzed by sequencing tests, allele-specific PCR and digestion by BsaX I. A monoclonal pattern was found in 4 out of 14 children (28.5%) and 45% of informative adults. Heterozygous V617FJAK2 was found less frequently in children than in adults (p<0.009). Only two girls showed both the V617FJAK2 mutation and a monoclonal pattern; one of them was the only child presenting a major thrombotic complication.
In contrast to adults, most children with ET do not show either a clonal disorder or the V617FJAK2 mutation.
