| Identity |
| Other names | Paired box homeotic gene 9 |
| HGNC | PAX9 |
| Location | 14q12 |
| DNA/RNA |
| Description | 4 exons |
| Transcription | 3 alternative splicing isoforms |
| Pseudogene | No |
| Protein |
| Description | 341 amino acids; 36.3 kDa |
| Expression | PAX9 is expressed in developing somites, specifically in the posterior ventrolateral region. These cells undergo an epithelial-mesenchymal transition, gaining increased motile capability as a consequence. Subsequent migration of this population generates the lateral sclerotome, which in turn gives rise to the ribs and neural arches. PAX9 contains a DNA binding paired domain, an octapeptide region and a carboxyl-terminal transactivation domain. |
| Localisation | Nuclear. |
| Function | PAX9 is a transcription factor that regulates the expression of genes involved in mediating cell proliferation, resistance to apoptosis, and cell migration. Mice homozygous for Pax9 mutations die shortly after birth, lacking the thymus, parathyroid glands and ultimobranchial bodies derived from the third and fourth pharangeal pouches, presenting aberrant head and visceral skeleton development and a complete absence of teeth. |
| Homology | PAX9 shares homology through the conserved paired box domain with the other members of the nine strong PAX gene family. |
| Mutations |
| Germinal | PAX9 mutations are associated with oligodontia. |
| Implicated in |
| Entity | Oligodontia |
| Disease | Caused by missense and frameshift PAX9 mutations. Patients present normal primary dentition but lack most permanent molars. |
| Entity | Jarcho-Levin syndrome |
| Disease | In humans, a reduction in expression levels of Pax9, together with those of the related Pax1 gene, have been reported in vertebral column chondrocytes of autopsied foeti presenting Jarcho-Levin syndrome, a segmentation anomaly affecting thoracic and vertebral skeletal development. This syndrome shares similarities with the phenotype of the Pax9/Pax1 double mutant mouse. |
| Entity | Oesophageal invasive carcinoma and epithelial dysplasia. |
| Disease | PAX9 expression levels are significantly reduced in oesophageal invasive carcinoma and epithelial dysplasias compared to levels in normal tissue. There is a correlation between decreasing PAX9 expression and increased malignancy of the cancer. |
| Prognosis | Elevated PAX9 expression may be a useful prognostic marker indicative of favourable outcome in patients presenting oesophageal invasive carcinoma. |
| External links |
| Bibliography |
| The paired box encodes a second DNA-binding domain in the paired homeo domain protein. |
| Treisman J, Harris E, Desplan C |
| Genes & development. 1991 ; 5 (4) : 594-604. |
| PMID 1672661 |
| Pax genes and organogenesis. |
| Dahl E, Koseki H, Balling R |
| BioEssays : news and reviews in molecular, cellular and developmental biology. 1997 ; 19 (9) : 755-765. |
| PMID 9297966 |
| Pax9-deficient mice lack pharyngeal pouch derivatives and teeth and exhibit craniofacial and limb abnormalities. |
| Peters H, Neubšser A, Kratochwil K, Balling R |
| Genes & development. 1998 ; 12 (17) : 2735-2747. |
| PMID 9732271 |
| Pax1 and Pax9 synergistically regulate vertebral column development. |
| Peters H, Wilm B, Sakai N, Imai K, Maas R, Balling R |
| Development (Cambridge, England). 1999 ; 126 (23) : 5399-5408. |
| PMID 10556064 |
| Mutation of PAX9 is associated with oligodontia. |
| Stockton DW, Das P, Goldenberg M, D'Souza RN, Patel PI |
| Nature genetics. 2000 ; 24 (1) : 18-19. |
| PMID 10615120 |
| Haploinsufficiency of PAX9 is associated with autosomal dominant hypodontia. |
| Das P, Stockton DW, Bauer C, Shaffer LG, D'Souza RN, Wright T, Patel PI |
| Human genetics. 2002 ; 110 (4) : 371-376. |
| PMID 11941488 |
| Progressive loss of PAX9 expression correlates with increasing malignancy of dysplastic and cancerous epithelium of the human oesophagus. |
| Gerber JK, Richter T, Kremmer E, Adamski J, Hfler H, Balling R, Peters H |
| The Journal of pathology. 2002 ; 197 (3) : 293-297. |
| PMID 12115874 |
| Aberrant Pax1 and Pax9 expression in Jarcho-Levin syndrome: report of two Caucasian siblings and literature review. |
| Bannykh SI, Emery SC, Gerber JK, Jones KL, Benirschke K, Masliah E |
| American journal of medical genetics. Part A. 2003 ; 120 (2) : 241-246. |
| PMID 12833407 |
| A missense mutation in PAX9 in a family with distinct phenotype of oligodontia. |
| Lammi L, Halonen K, Pirinen S, Thesleff I, Arte S, Nieminen P |
| European journal of human genetics : EJHG. 2003 ; 11 (11) : 866-871. |
| PMID 14571272 |
| Pax1 and Pax9 activate Bapx1 to induce chondrogenic differentiation in the sclerotome. |
| Rodrigo I, Hill RE, Balling R, Mšnsterberg A, Imai K |
| Development (Cambridge, England). 2003 ; 130 (3) : 473-482. |
| PMID 12490554 |
| Novel mutation of the initiation codon of PAX9 causes oligodontia. |
| Klein ML, Nieminen P, Lammi L, Niebuhr E, Kreiborg S |
| Journal of dental research. 2005 ; 84 (1) : 43-47. |
| PMID 15615874 |
| REVIEW articles | automatic search in PubMed |
| Last year publications | automatic search in PubMed |
| Contributor(s) |
| Written | 08-2005 | Ewan Robson, Jess Whall, Michael Eccles |
| Citation |
| This paper should be referenced as such : |
| Robson E, Whall J, Eccles M . PAX9 (Paired box gene 9). Atlas Genet Cytogenet Oncol Haematol. August 2005 . URL : http://AtlasGeneticsOncology.org/Genes/PAX9ID41644ch14q12.html |
| © Atlas of Genetics and Cytogenetics in Oncology and Haematology | indexed on : Mon Aug 11 21:16:16 2008 |
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