| Written | 2007-07 | Clelia Tiziana Storlazzi, Fredrik Mertens |
| Department of Genetics, Microbiology, University of Bari, Bari, Italy (CTS); Department of Clinical Genetics, Lund University Hospital, Lund, Sweden (FM) |
| Identity |
| ICD-Topo | C400-C403,C408-C414,C418-C419 BONES & JOINTS |
| Atlas_Id | 5526 |
| Phylum | Bones::Subungual exostosis |
| Other names | Dupuytren's exostosis |
| Classification |
| Note | Benign bone-producing neoplasm of unknown cellular origin. |
| Clinics and Pathology |
| Disease | Subungual exostosis. |
| Phenotype / cell stem origin | Unknown. |
| Embryonic origin | Unknown. |
| Etiology | Unknown. |
| Epidemiology | Affects children and young adults. |
| Clinics | Subungual exostosis usually presents as a slowly growing, painful mass localized dorsomedially in the distal phalanx, and in contrast to osteochondroma, there is usually no continuity with the underlying cortex. |
| Treatment | Surgical excision, but local recurrences are not uncommon. |
| Prognosis | Excellent. |
| Cytogenetics |
| Cytogenetics Morphological | t(X;6)(q22;q13-14). |
 | |
| Partial G-banding karyotype showing chromosomes 6 and X in a case of subungual exostosis. The arrows indicate the breakpoints. | |
| Cytogenetics Molecular | A Probe specific for COL12A1 (RP11-815E21) identified the breakpoint in 6q14.1, as it showed splitting signals on der(X) and der(6). On the same chromosomes, these signals colocalized with the signals of RP11-815E21, encompassing the COL4A5 and IRS4 genes in band Xq22.3. |
 | |
| FISH experiment revealing the breakpoint regions on both chromosomes 6 and X on a case of subungual exostosis. | |
| Probes | RP11-815E21 (COL4A5 and IRS4); RP11-1072D13 (COL12A1). |
| Variants | The breakpoint on chromosome 6 could be centromeric to COL4A5, in an unknown location. |
| Genes involved and Proteins |
| Gene Name | COL4A5 |
| Location | Xq22.3 |
| Note | It is currently unknown whether any of these two genes is involved in the pathogenesis of subungual exostosis. |
| Dna / Rna | Genomic (chrX:107,569,810-107,827,431). Three transcript variants: isoform 1 (NM_000495), isoform 2 (NM_033380), isoform 3 (NM_03338). |
| Protein | Three proteins, respectively encoded by the isoform 1 (695 aa), isoform 2 (1691 aa), and isoform 3 (1688 aa). |
| Gene Name | COL12A1 |
| Location | 6q13 |
| Dna / Rna | Genomic (chr6:75,850,762-75,972,343). Two transcript variants, a long (NM_004370) and a short isoform (NM_080645). |
| Protein | Two proteins: 1899 amino acids (aa) and 3063 aa, respectively encoded by the short and long transcript isoforms. |
| Result of the chromosomal anomaly |
| Hybrid Gene | |
| Note | No detected fusion gene. |
| To be noted |
| To elucidate how the transcription of these genes is affected by the translocation, further fresh or fresh frozen samples need to be studied. |
| Bibliography |
| Clonal chromosome abnormalities in a so-called Dupuytren's subungual exostosis. |
| Dal Cin P, Pauwels P, Poldermans LJ, Sciot R, Van den Berghe H |
| Genes, chromosomes & cancer. 1999 ; 24 (2) : 162-164. |
| PMID 9885985 |
| Subungual exostosis of the third toe. |
| Ilyas W, Geskin L, Joseph AK, Seraly MP |
| Journal of the American Academy of Dermatology. 2001 ; 45 (6 Suppl) : S200-S201. |
| PMID 11712058 |
| Imaging of osteochondroma: variants and complications with radiologic-pathologic correlation. |
| Murphey MD, Choi JJ, Kransdorf MJ, Flemming DJ, Gannon FH |
| Radiographics : a review publication of the Radiological Society of North America, Inc. 2000 ; 20 (5) : 1407-1434. |
| PMID 10992031 |
| Rearrangement of the COL12A1 and COL4A5 genes in subungual exostosis: molecular cytogenetic delineation of the tumor-specific translocation t(X;6)(q13-14;q22). |
| Storlazzi CT, Wozniak A, Panagopoulos I, Sciot R, Mandahl N, Mertens F, Debiec-Rychter M |
| International journal of cancer. Journal international du cancer. 2006 ; 118 (8) : 1972-1976. |
| PMID 16284948 |
| Distinct chromosomal rearrangements in subungual (Dupuytren) exostosis and bizarre parosteal osteochondromatous proliferation (Nora lesion). |
| Zambrano E, Nosé V, Perez-Atayde AR, Gebhardt M, Hresko MT, Kleinman P, Richkind KE, Kozakewich HP |
| The American journal of surgical pathology. 2004 ; 28 (8) : 1033-1039. |
| PMID 15252309 |
| Citation |
| This paper should be referenced as such : |
| Storlazzi, CT ; Mertens, F |
| Bone: Subungual exostosis with t(X;6)(q13;q22) |
| Atlas Genet Cytogenet Oncol Haematol. 2008;12(3):253-254. |
| Free journal version : [ pdf ] [ DOI ] |
| On line version : http://AtlasGeneticsOncology.org/Tumors/SubungExosttX6ID5526.html |
| Translocations implicated (Data extracted from papers in the Atlas) |
| t(X;6)(q13;q22) COL4A5 and COL12A1 | |
| External links |
| REVIEW articles | automatic search in PubMed |
| Last year articles | automatic search in PubMed |
| © Atlas of Genetics and Cytogenetics in Oncology and Haematology | indexed on : Fri Jun 30 11:25:12 CEST 2017 |
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