Medicina: Oncoematologia pediatrica: Leucemia linfoblastica acuta
| English |
| philadelphia chromosome |
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| Attestation |
3
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| Definition |
Characteristic chromosomal abnormality in which a portion of chromosome 22 is translocated to chromosome 9. This abnormality is found in nearly all cases of chronic myeloid leukaemia and some cases of acute lymphoblastic leukemia.
The name applied to the abnormality of the chromosome number 22 in the marrow and blood cells of patients with some forms of leukemia. The abnormality reflects a shortened long arm of chromosome number 22. The observation was reported first by physicians at the University of Pennsylvania and named the Philadelphia chromosome. Since its discovery, the piece of chromosome lost has been shown to stick (translocate) to chromosome 9 in most cases. Indeed, some of chromosome 9 sticks (translocates) to chromosome 22. This is referred to as a balanced translocation, because virtually equal lengths of partial chromosome arms exchange position. Because chromosome 22 is a very short chromosome and chromosome 9 is a very long chromosome, the addition to chromosome 9 was less apparent than the shortening of 22 until more sensitive techniques became available. The abnormality of chromosome 22 is now usually abbreviated to the Ph chromosome.
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| Definition source |
http://www.graylab.ac.uk/cgi-bin/omd?Philadelphia+chromosome
http://www.leukemia.org/all_glossary.adp
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| Context |
The presence of the t(9;22)(q34;q11) translocation,commonly known as Philadelphia chromosome (Ph1), in about 3% to 5% of all children with ALL is considered as one of the molecular markers associated with a particularly high risk for treatment failure.
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| Context source |
en16
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| Figure source |
Pession, (2002).
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| Synonym |
Ph chromosome, chromosome number 22.
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| Subject field |
Pediatric Oncohematology
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| Related concept |
Philadelphia-chromosome positive ALL, Philadelphia Chromosome-Positive (Ph+) Childhood Acute Lymphoblastic Leukemia
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| de |
Philadelphia-Chromosom
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| it |
cromosoma Philadelphia
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| Reliability code |
3
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