Philadelphia chromosome: Difference between revisions

From Embryology
Line 35: Line 35:
|-
|-
|
|
* about 140 million DNA base pairs
* about 4.5 % of the total DNA
* contains between 800 and 1,300 genes
|
|
* about 132 million DNA base pairs
* about 132 million DNA base pairs

Revision as of 11:10, 9 May 2011

Notice - Mark Hill
Currently this page is only a template and will be updated (this notice removed when completed).

Introduction

Philadelphia chromosome

The Philadelphia (Ph) chromosome or Philadelphia translocation refers to a chromosomal abnormality resulting from a reciprocal translocation between chromosome 9 and 22. This is described by the genetic molecular shorthand t(9;22)(q34;q11).

The translocation is associated with the disease chronic myelogenous leukemia (CML).

Genetic Links: genetic abnormalities | maternal age | Trisomy 21 | Trisomy 18 | Trisomy 13 | Trisomy X | trisomy mosaicism | Monosomy | Fragile X | Williams | Alagille | Philadelphia chromosome | mitochondria | VACTERL | hydatidiform mole | epigenetics | Prenatal Diagnosis | Neonatal Diagnosis | meiosis | mitosis | International Classification of Diseases | genetics

| Cell Division - Meiosis | Cell Division - Mitosis

Some Recent Findings

  • Molecular cytogenetic characterization of variant Philadelphia translocations in chronic myeloid leukemia: genesis and deletion of derivative chromosome 9 [1] "The mechanisms for the formation of variant Philadelphia (Ph) translocations that occur in 5-10% of patients with chronic myeloid leukemia (CML) are not fully characterized. ...Of 336 CML patients who presented at diagnosis and were studied by conventional cytogenetics and fluorescence in situ hybridization (FISH), 25 patients (7.44%) exhibited variant Ph-rearrangements. All chromosomes could be implicated in variant Ph rearrangements, with 32 breakpoints defined. Their distribution was located preferentially in the CG-richest regions of the genome. Deletions on der(9) were observed in 15 of the 25 cases (60%), a greater proportion in typical Ph translocations (12-15%)."

History

The following abstract is from a 2007 paper written by one of the original discoverers of this chromosomal abnormality and its association with chronic myelogenous leukemia.[2] This issue of the Journal of Clinical Investigation also devotes a section of papers in a Review Series].

Discovery of the Philadelphia chromosome: a personal perspective

J Clin Invest. 2007 Aug;117(8):2033-5. Nowell PC.

Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-6082, USA. nowell@mail.med.upenn.edu

"Almost 50 years ago, David Hungerford and I noticed an abnormally small chromosome in cells from patients with chronic myelogenous leukemia (CML). This article is a personal perspective of the events leading to the discovery of this chromosome, which became known as the Philadelphia chromosome. As technology advanced over subsequent decades, the translocation resulting in the Philadelphia chromosome has been identified, its role in the development of CML has been confirmed, and a therapy directed against the abnormal protein it produces has shown promising results in the treatment of patients with CML."

Chromosome 9 and 12

Human idiogram
Human idiogram-chromosome 09.jpg Human idiogram-chromosome 12.jpg
  • about 140 million DNA base pairs
  • about 4.5 % of the total DNA
  • contains between 800 and 1,300 genes
  • about 132 million DNA base pairs
  • about 4 to 4.5 % of the total DNA
  • contains between 1,200 and 1,400 genes
Human Chromosomes: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | X | Y  
Idiogram Chromosome Banding - The term refers to the light and dark pattern, seen after staining with a dye, of individual chromosomes identified in metaphase. It is only in meiosis and mitosis during metaphase that chromosomes can be easily identified, during the normal cell life (interphase) the chromosomes are unravelled and distributed within the nucleus in chromosome territories. A band is that part of a chromosome which is clearly distinguishable from nearby regions by appearing darker or brighter with one or more banding techniques.
Human Idiogram: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | X | Y
Genetic abnormality locations: 1-4 | 5-8 | 9-12 | 13-16 | 17-20 | 21-XY | sSMC
Inheritance Pattern images: Genetic Abnormalities | autosomal dominant | autosomal recessive | X-linked dominant (affected father) | X-Linked dominant (affected mother) | X-Linked recessive (affected father) | X-Linked recessive (carrier mother) | mitochondrial inheritance | Codominant inheritance | Genogram symbols | Genetics
Links: Genetics | Abnormal Development - Genetic

Cite this page: Hill, M.A. (2024, April 16) Embryology Philadelphia chromosome. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Philadelphia_chromosome

What Links Here?
© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G


References

  1. <pubmed>19737651</pubmed>
  2. <pubmed>17671636</pubmed>| PMC1934591 | J Clin Invest.

Reviews

Articles

Search Pubmed

Search Pubmed: Philadelphia chromosome | Philadelphia translocation | chronic myelogenous leukemia

Glossary Links

Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link

Cite this page: Hill, M.A. (2024, April 16) Embryology Philadelphia chromosome. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Philadelphia_chromosome

What Links Here?
© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G