title: Are all cases of paediatric essential thrombocythaemia really myeloproliferative neoplasms? Analysis of a large cohort.
abstract: Sporadic essential thrombocythaemia (ET) is rare in paediatrics, and the diagnostic and clinical approach to paediatric cases cannot be simply copied from experience with adults. Here, we assessed 89 children with a clinical diagnosis of ET and found that 23 patients (25·8%) had a clonal disease. The JAK2 V617F mutation was identified in 14 children, 1 child had the MPL W515L mutation, and 6 had CALR mutations. The monoclonal X-chromosome inactivation pattern was seen in six patients (two with JAK2 V617F and two with CALR mutations). The other 66 patients (74·2%) had persistent thrombocytosis with no clonality. There were no clinical or haematological differences between the clonal and non-clonal patients. The relative proportion of ET-specific mutations in the clonal children was much the same as in adults. The higher prevalence of non-clonal cases suggests that some patients may not have myeloproliferative neoplasms, with significant implications for their treatment.
authors.affiliation: Department of Medicine - DIMED, Internal Medicine-CLOPD, University of Padova, Padova, Italy.
authors.forename: Maria L
authors.initials: ML
authors.lastname: Randi
authors.forename: Giulia
authors.initials: G
authors.lastname: Geranio
authors.forename: Irene
authors.initials: I
authors.lastname: Bertozzi
authors.forename: Concetta
authors.initials: C
authors.lastname: Micalizzi
authors.forename: Ugo
authors.initials: U
authors.lastname: Ramenghi
authors.forename: Fabio
authors.initials: F
authors.lastname: Tucci
authors.forename: Lucia D
authors.initials: LD
authors.lastname: Notarangelo
authors.forename: Saverio
authors.initials: S
authors.lastname: Ladogana
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Menna
authors.forename: Paola
authors.initials: P
authors.lastname: Giordano
authors.forename: Caterina
authors.initials: C
authors.lastname: Consarino
authors.forename: Piero
authors.initials: P
authors.lastname: Farruggia
authors.forename: Giulio A
authors.initials: GA
authors.lastname: Zanazzo
authors.forename: Giovanni M
authors.initials: GM
authors.lastname: Fiori
authors.forename: Roberta
authors.initials: R
authors.lastname: Burnelli
authors.forename: Giovanna
authors.initials: G
authors.lastname: Russo
authors.forename: Momcilo
authors.initials: M
authors.lastname: Jankovich
authors.forename: Edoardo
authors.initials: E
authors.lastname: Peroni
authors.forename: Elena
authors.initials: E
authors.lastname: Duner
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Basso
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Fabris
authors.forename: Maria C
authors.initials: MC
authors.lastname: Putti
mesh_terms: D000293:Adolescent; D000328:Adult; D019943:Amino Acid Substitution; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D019337:Hematologic Neoplasms / Q000235:genetics* / Q000628:therapy; D006801:Humans; D007223:Infant; D053614:Janus Kinase 2 / Q000235:genetics*; D008297:Male; D020125:Mutation, Missense; D009363:Neoplasm Proteins / Q000235:genetics*; D013920:Thrombocythemia, Essential / Q000235:genetics* / Q000628:therapy
chemical_list: D009363:Neoplasm Proteins; C507924:JAK2 protein, human; D053614:Janus Kinase 2
keywords: CALR; JAK2; essential thrombocythaemia; myeloproliferative neoplasm; paediatric