title: Normal thrombopoietin and its receptor (c-mpl) genes in children with essential thrombocythemia.
abstract: BACKGROUND
  Following the observation of thrombopoietin (TPO) gene abnormalities as the cause of familiar cases of thrombocythemia similar derangements of TPO and/or its receptor (c-mpl) might be surmised to be at the root of increased platelet count also in non-familiar (sporadic) cases. Although this was not demonstrated in adults, little data exist about childhood.
  
  
  METHODS
  We studied the molecular biology of TPO and c-mpl in seven children with non-familiar essential thrombocythemia (ET) and one child with secondary thrombocytosis (ST). Plasma TPO content was measured using a commercially available kit. Genomic DNA was extracted from whole blood by standard methods and TPO and c-mpl genes were amplified by polymerase chain reaction (PCR) and sequenced.
  
  
  RESULTS
  Plasma TPO levels were normal in all our patients. No alteration was detected in either coding region, including the flanking intronic sequences of TPO and c-mpl genes. As compared to the published normal sequence of the TPO gene, one allelic base change in a non-coding region of intron 1 was found in all children with ET and ST, but this was reported as a common finding in normal subjects as well.
  
  
  CONCLUSIONS
  High platelet count in our series of sporadic ET of childhood is not due to an abnormality either of TPO or c-mpl gene.
authors.affiliation: Department of Medical and Surgical Sciences, University of Padua Medical School, Padua, Italy. marialuigia.randi@unipd.it
authors.forename: M L
authors.initials: ML
authors.lastname: Randi
authors.forename: M C
authors.initials: MC
authors.lastname: Putti
authors.forename: E
authors.initials: E
authors.lastname: Pacquola
authors.forename: G
authors.initials: G
authors.lastname: Luzzatto
authors.forename: L
authors.initials: L
authors.lastname: Zanesco
authors.forename: F
authors.initials: F
authors.lastname: Fabris
mesh_terms: D000293:Adolescent; D002648:Child; D004247:DNA / Q000032:analysis; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009363:Neoplasm Proteins / Q000235:genetics* / Q000502:physiology*; D016133:Polymerase Chain Reaction; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000502:physiology*; D018121:Receptors, Cytokine / Q000235:genetics* / Q000502:physiology*; D053628:Receptors, Thrombopoietin; D013920:Thrombocythemia, Essential / Q000235:genetics* / Q000503:physiopathology*; D013926:Thrombopoietin / Q000235:genetics* / Q000494:pharmacology*
chemical_list: D009363:Neoplasm Proteins; D011518:Proto-Oncogene Proteins; D018121:Receptors, Cytokine; D053628:Receptors, Thrombopoietin; C082218:MPL protein, human; D004247:DNA; D013926:Thrombopoietin