Philadelphia-chromosome positive essential thrombocythemia. Two cases in children.
Two cases of children with essential thrombocythemia (ET) with the presence of a Philadelphia chromosome (Ph1) are presented and discussed. Diagnosis was based on their clinical presentation and marked primary thrombocytosis. The site of the Ph1 translocation, as detected by a 1.2-kb bcr genomic probe, differed in the two patients. These cases, along with other reported cases of Ph1-positive ET in the literature, suggest that the presence of the Ph1 cannot be used to rule out a diagnosis of ET. Additionally, the differing translocation sites in these cases suggests that the exact translocation site may not be significant in determining which cell lineage will predominate in a Ph1-positive myeloproliferative disorder.
Kastan
M B
MB
Division of Pediatric Oncology, Johns Hopkins Hospital, Baltimore, MD 21205.
Zehnbauer
B A
BA
Leventhal
B G
BG
Corden
B J
BJ
Dover
G J
GJ
D000293:Adolescent; D002675:Child, Preschool; D015342:DNA Probes; D005260:Female; D006801:Humans; D008297:Male; D010677:Philadelphia Chromosome; D013920:Thrombocythemia, Essential / Q000235:genetics*; D014178:Translocation, Genetic / Q000235:genetics*
D015342:DNA Probes