Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 4 complete abstracts (903 words), 10 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
An aberrant form of human chromosome 22 characterized by translocation of the distal end of chromosome 9 from 9q34, to the long arm of chromosome 22 at 22q11. It is present in the bone marrow cells of 80 to 90 per cent of patients with chronic myelocytic leukemia (leukemia, myelogenous, chronic, bcr-abl positive).
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: Chromosome, Philadelphia; Ph1 Chromosome; Chromosome, Ph1; Chromosomes, Ph1; Ph1 Chromosomes; Ph 1 Chromosome; 1 Chromosomes, Ph; Chromosome, Ph 1.
Where it fits in the MeSH classification
- Broader topics
- Chromosomes, Human, Pair 9; Chromosomes, Human, Pair 22; Translocation, Genetic
- See also
- Oncogene Proteins, Fusion
Related concepts
- Chromosomes
- Leukemia
- Myelogenous
- Chronic
- Bcr-Abl Positive
Research landscape
PubMed indexes 3,389 records tagged with the MeSH heading “Philadelphia Chromosome” (counts retrieved 2026-10-29). 688 of them (20.3%) were published from 2020 onward, and the busiest period so far is through 1999 with 1,200 records.
Reviews account for 607 records (17.9%) and meta-analyses for 21. Randomized controlled trials number 43 (1.3%) as a share of all records on the topic. Randomized trials make up only a small share of this literature, so much of what is known comes from laboratory, observational or descriptive work.
Show the data
| Period | Records |
|---|---|
| through 1999 | 1,200 |
| 2000-2009 | 694 |
| 2010-2019 | 807 |
| 2020 onward | 688 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 607 | 17.9% |
| Meta-analyses | 21 | 0.6% |
| Randomized controlled trials | 43 | 1.3% |
Method: PubMed query "Philadelphia Chromosome"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-29.
Reading the evidence in genetics and genomics
Genetic findings vary widely in strength. A variant linked to a condition in one study may not replicate in other ancestries, and most common variants have small effects that are meaningful only in aggregate. Studies of rare, high-impact variants can support strong causal claims about a gene, while association studies describe statistical links that need functional and independent replication. Check the sample size, the ancestry of participants, whether results were replicated, and whether a laboratory or clinical outcome was actually measured.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
ATG7 regulates energy metabolism, differentiation and survival of Philadelphia-chromosome-positive cells [1]
Abstract reading summary — source excerpts
- Opening excerpt
- A major drawback of tyrosine kinase inhibitor (TKI) treatment in chronic myeloid leukemia (CML) is that primitive CML cells are able to survive TKI-mediated BCR-ABL inhibition, leading to disease persistence in patients.
- Closing excerpt
- Finally, ATG7 knockdown sensitizes CML progenitor cells to TKI-induced death, without affecting survival of normal cells, suggesting that specific inhibitors of ATG7 in combination with TKI would provide a novel therapeutic approach for CML patients exhibiting persistent disease.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (218 words)
A major drawback of tyrosine kinase inhibitor (TKI) treatment in chronic myeloid leukemia (CML) is that primitive CML cells are able to survive TKI-mediated BCR-ABL inhibition, leading to disease persistence in patients. Investigation of strategies aiming to inhibit alternative survival pathways in CML is therefore critical. We have previously shown that a nonspecific pharmacological inhibition of autophagy potentiates TKI-induced death in Philadelphia chromosome-positive cells. Here we provide further understanding of how specific and pharmacological autophagy inhibition affects nonmitochondrial and mitochondrial energy metabolism and reactive oxygen species (ROS)-mediated differentiation of CML cells and highlight ATG7 (a critical component of the LC3 conjugation system) as a potential specific therapeutic target. By combining extra- and intracellular steady state metabolite measurements by liquid chromatography-mass spectrometry with metabolic flux assays using labeled glucose and functional assays, we demonstrate that knockdown of ATG7 results in decreased glycolysis and increased flux of labeled carbons through the mitochondrial tricarboxylic acid cycle. This leads to increased oxidative phosphorylation and mitochondrial ROS accumulation. Furthermore, following ROS accumulation, CML cells, including primary CML CD34(+) progenitor cells, differentiate toward the erythroid lineage. Finally, ATG7 knockdown sensitizes CML progenitor cells to TKI-induced death, without affecting survival of normal cells, suggesting that specific inhibitors of ATG7 in combination with TKI would provide a novel therapeutic approach for CML patients exhibiting persistent disease.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 27168493 · DOI · PMC4922442
Treatment and monitoring of Philadelphia chromosome-positive leukemia patients: recent advances and remaining challenges [2]
Abstract reading summary — source excerpts
- Opening excerpt
- The Philadelphia (Ph) chromosome, resulting from the t(9;22)(q34;q11) translocation, can be found in chronic myeloid leukemia (CML) as well as in a subset of acute lymphoblastic leukemias (ALL).
- Closing excerpt
- In this review, we discuss the latest advances in treatment and monitoring of CML and Ph+ ALL and the issues that still need to be addressed to make the best use of the therapeutic armamentarium and molecular testing technologies currently at our disposal.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (281 words)
The Philadelphia (Ph) chromosome, resulting from the t(9;22)(q34;q11) translocation, can be found in chronic myeloid leukemia (CML) as well as in a subset of acute lymphoblastic leukemias (ALL). The deregulated BCR-ABL1 tyrosine kinase encoded by the fusion gene resulting from the translocation is considered the pathogenetic driver and can be therapeutically targeted. In both CML and Ph-positive (Ph+) ALL, tyrosine kinase inhibitors (TKIs) have significantly improved outcomes. In the TKI era, testing for BCR-ABL1 transcript levels by real-time quantitative polymerase chain reaction (RQ-PCR) has become the gold standard to monitor patient response, anticipate relapse, and guide therapeutic decisions. In CML, key molecular response milestones have been defined that draw the ideal trajectory towards optimal long-term outcomes. Treatment discontinuation (treatment-free remission, TFR) has proven feasible in a proportion of patients, and clinical efforts are now focused on how to increase this proportion and how to best select TFR candidates. In Ph+ ALL, results of trials with second- and third-generation TKIs are challenging the role of intensive chemotherapy and even that of allogeneic stem cell transplantation. Additional weapons are offered by the recently introduced monoclonal antibodies. In patients harboring mutations in the BCR-ABL1 kinase domain, prompt therapeutic reassessment and individualization based on mutation status are important to regain response and prevent disease progression. Next-generation sequencing is likely to become a precious tool for mutation testing because of the greater sensitivity and the possibility to discriminate between compound and polyclonal mutations. In this review, we discuss the latest advances in treatment and monitoring of CML and Ph+ ALL and the issues that still need to be addressed to make the best use of the therapeutic armamentarium and molecular testing technologies currently at our disposal.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 31014376 · DOI · PMC6480772
In vitro megakaryocyte differentiation and proplatelet formation in Ph-negative classical myeloproliferative neoplasms: distinct patterns in the different clinical phenotypes [3]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundPh-negative myeloproliferative neoplasms (MPNs) are clonal disorders that include primary myelofibrosis (PMF), polycythemia vera (PV) and essential thrombocythemia (ET).
- Closing excerpt
- Profound differences in megakaryocyte morphology and proplatelet formation distinguish PMF, both fibrotic and prefibrotic, from ET and PV.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (205 words)
BackgroundPh-negative myeloproliferative neoplasms (MPNs) are clonal disorders that include primary myelofibrosis (PMF), polycythemia vera (PV) and essential thrombocythemia (ET). Although the pathogenesis of MPNs is still incompletely understood, an involvement of the megakaryocyte lineage is a distinctive feature.Methodology/principal findingsWe analyzed the in vitro megakaryocyte differentiation and proplatelet formation in 30 PMF, 8 ET, 8 PV patients, and 17 healthy controls (CTRL). Megakaryocytes were differentiated from peripheral blood CD34(+) or CD45(+) cells in the presence of thrombopoietin. Megakaryocyte output was higher in MPN patients than in CTRL with no correlation with the JAK2 V617F mutation. PMF-derived megakaryocytes displayed nuclei with a bulbous appearance, were smaller than ET- or PV-derived megakaryocytes and formed proplatelets that presented several structural alterations. In contrast, ET- and PV-derived megakaryocytes produced more proplatelets with a striking increase in bifurcations and tips compared to both control and PMF. Proplatelets formation was correlated with platelet counts in patient peripheral blood. Patients with pre-fibrotic PMF had a pattern of megakaryocyte proliferation and proplatelet formation that was similar to that of fibrotic PMF and different from that of ET.Conclusions/significanceIn conclusion, MPNs are associated with high megakaryocyte proliferative potential. Profound differences in megakaryocyte morphology and proplatelet formation distinguish PMF, both fibrotic and prefibrotic, from ET and PV.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 21698292 · DOI · PMC3115954
Transplantation outcomes in Philadelphia-positive acute lymphoblastic leukemia with additional cytogenetic abnormalities: A study on behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation [4]
Abstract reading summary — source excerpts
- Opening excerpt
- We compared the presence of additional chromosomal abnormalities (ACAs, n = 345) with a referent group with no ACAs (n = 169) (noACAs) in patients with Ph+ ALL receiving TKI before transplantation.
- Closing excerpt
- Administration of a TKI upfront, followed by transplantation, may overcome the poor prognostic influence of ACAs in Ph+ ALL.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (199 words)
We compared the presence of additional chromosomal abnormalities (ACAs, n = 345) with a referent group with no ACAs (n = 169) (noACAs) in patients with Ph+ ALL receiving TKI before transplantation. The groups did not differ significantly in age, gender, or interval from diagnosis to transplantation. More patients with ACAs received PB grafts (86.4% vs. 78.1%, p = 0.03), while more patients in the noACAs group received myeloablative conditioning (87% vs. 75.9%, p = 0.003). Day 30 ANC (≥109/L) was 97.9% vs. 98.2%, and day 60 platelet count (≥20 × 109/L) was 93.9% vs. 95.5%. Day 100 acute GVHD grades II-IV was 26.4% vs. 31%, and of grades III-IV was 8.6% vs. 9.7%. 4-year chronic GVHD was 40.5% vs. 39.9%, and the proportion of extensive chronic GVHD was 19.3% vs. 20.1%. 4-year NRM was 13.1% vs. 13.5%, and 4-year RI was 19.2% vs. 21.1%; 4-year LFS and OS were 67.7% vs. 65.4% and 76.3% vs. 78.5%. 4-year GRFS was 48.5% vs. 45%, respectively. In multivariable analysis, having ACAs and the number of ACAs did not significantly affect transplant outcomes. Administration of a TKI upfront, followed by transplantation, may overcome the poor prognostic influence of ACAs in Ph+ ALL.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42443469 · DOI · PMC13569436
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article Translation of the Philadelphia chromosome into therapy for CML [5]
- Research article The molecular genetics of Philadelphia chromosome-positive leukemias [6]
- Research article Philadelphia chromosome-like acute lymphoblastic leukemia [7]
- Research article Philadelphia chromosome-positive leukemias: from basic mechanisms to molecular therapeutics [8]
- Research article Use of tyrosine kinase inhibitors to prevent relapse after allogeneic hematopoietic stem cell transplantation for patients with Philadelphia chromosome-positive acute lymphoblastic leukemia: A position statement of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation [9]
- Research article Dasatinib: a tyrosine kinase inhibitor for the treatment of chronic myelogenous leukemia and philadelphia chromosome-positive acute lymphoblastic leukemia [10]
References
- Karvela M, Baquero P, Kuntz EM, Mukhopadhyay A, Mitchell R, Allan EK, et al.. ATG7 regulates energy metabolism, differentiation and survival of Philadelphia-chromosome-positive cells. . 2016. PMID 27168493 · DOI · PMC4922442
- Soverini S, Bassan R, Lion T. Treatment and monitoring of Philadelphia chromosome-positive leukemia patients: recent advances and remaining challenges. . 2019. PMID 31014376 · DOI · PMC6480772
- Balduini A, Badalucco S, Pugliano MT, Baev D, De Silvestri A, Cattaneo M, et al.. In vitro megakaryocyte differentiation and proplatelet formation in Ph-negative classical myeloproliferative neoplasms: distinct patterns in the different clinical phenotypes. . 2011. PMID 21698292 · DOI · PMC3115954
- Nagler A, Esteve J, Galimard JE, Wu D, Jiang E, Dhedin N, et al.. Transplantation outcomes in Philadelphia-positive acute lymphoblastic leukemia with additional cytogenetic abnormalities: A study on behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation. . 2026. PMID 42443469 · DOI · PMC13569436
- Druker BJ. Translation of the Philadelphia chromosome into therapy for CML. Blood. 2008. PMID 19064740 · DOI
- Kurzrock R, Gutterman JU, Talpaz M. The molecular genetics of Philadelphia chromosome-positive leukemias. N Engl J Med. 1988. PMID 3047582 · DOI
- Tasian SK, Loh ML, Hunger SP. Philadelphia chromosome-like acute lymphoblastic leukemia. Blood. 2017. PMID 28972016 · DOI · PMC5680607
- Kurzrock R, Kantarjian HM, Druker BJ, Talpaz M. Philadelphia chromosome-positive leukemias: from basic mechanisms to molecular therapeutics. Ann Intern Med. 2003. PMID 12755554 · DOI
- Giebel S, Czyz A, Ottmann O, Baron F, Brissot E, Ciceri F, et al.. Use of tyrosine kinase inhibitors to prevent relapse after allogeneic hematopoietic stem cell transplantation for patients with Philadelphia chromosome-positive acute lymphoblastic leukemia: A position statement of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation. Cancer. 2016. PMID 27309127 · DOI
- Steinberg M. Dasatinib: a tyrosine kinase inhibitor for the treatment of chronic myelogenous leukemia and philadelphia chromosome-positive acute lymphoblastic leukemia. Clin Ther. 2007. PMID 18158072 · DOI
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-10-31; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-10-29.
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Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.