Atlas of Genetics and Cytogenetics in Oncology and Haematology
-7/del(7q) in adults
| Identity |
| Note | -7/del(7q) in childhood blood malignancies exhibits a specific pattern of pathogenesis; chromosome 7 anomalies are not rare in acute lymphocytic leukaemia (ALL); they occur in balanced translocations involving 7p15 or 7q34 in T lineage and 7q22 or 7q32 in B proliferations; monosomy 7 is present in 5 to 6 % of ALL, most often as a secondary anomaly of the t(9;22); the association t(9;22), -7 is present in 16 % of the Ph1+ ALL, i.e. in 3% of ALL as a whole; we will hereunder focuse on -7/del(7q) in adult myeloproliferations |
 | |
| del(7q) G- banding - Courtesy Jean-Luc Lai and Alain Vanderhaegen | |
| Clinics and Pathology |
| Disease | myelodysplastic syndromes (MDS) and acute non lymphocytic leukemia (ANLL); they may occur de novo, or be secondary to an exposure to chemical mutagens or to chemotherapy treatments with alkylating agents; may probably also be secondary to immunosuppressive therapy for severe aplastic anemia |
| Phenotype / cell stem origin | |
| Epidemiology | -7 is the most frequent abnormality in secondary myeloid disorders, found in 51% of the cases in a series of 246 cases, while del(7q) was found in 7%, and a partial monosomy 7 as a result of an unbalanced translocation in 8% of cases; in contrast, -7/del(7q) is found in 10% of de novo myeloid disorders; the sex ratio is 1.5 male for 1 female; the proportion of adults with a -7 myeloid disorder grows dramatically after 60 years |
| Clinics | characterized by infectious susceptibility, quick aggravation, and treatment resistance |
| Prognosis | monosomy 7 is classified as a poor prognostic criterium by the International Prognostic Scoring System; the actuarial relapse rate at one year is 82 %, and the 7-yr actuarial event-free survival is 6 %; after an allogeneic bone marrow transplantation, -7 is predictive of an unfavorable outcome |
| Cytogenetics |
| Cytogenetics Morphological | deletion (7q) is always interstitial; cluster of breakpoints in 7q11 to 7q36, is a with two common minimal zones in q22 and in q32-34 |
| Cytogenetics Molecular | using loss of heterogygocity (LOH) studies and YAC libraries, a 2 to 3 Mb segment in 7q22 has been designated as the proximal common deleted area; the 7q33-34 zone is the consensual area for the distal deletion; LOH studies suggest that a specific mechanism, such as mitotic recombination in bone marrow stem cell leading to homozygosity in both granulocytes and lymphocytes, may be implicated |
| Probes | chromosomal band 7q221: marker D7S658, through D7S2494, YAC HSC7E441 to HSC7E572; 7q33-34: D7S498 to D7S505; near-centromeric probes of chromosome 7 and 7q31 probes are produced by commercial companies |
| Additional anomalies | -5/del(5q), found in 40 to 60 % of the secondary MDS cases; trisomy 8 |
| Variants | the balanced translocation t(1;7)(q10;p10), and many unbalanced translocation, having for consequence a partial monosomy 7 of the 7q22 to 7q34 bands may, in a way, be considered as variants |
| Genes involved and Proteins |
| Note | -7/del(7q) is not only frequent in secondary MDS or ANLL, but also in leukemias occurring in individuals with constitutional syndromes including predisposition to myeloid disorders; these findings suggest the presence of a putative myeloid leukemia suppressor gene in the commonly deleted genomic segment 7q22 and even multiple genes in 7q22 -31.1 that are playing a role in leukemogenesis; candidate genes are : |
| External links |
| Other database | -7/del(7q) in adults | Mitelman database (CGAP - NCBI) |
| Bibliography |
| Correlation of occupation and karyotype in adults with acute nonlymphocytic leukemia. |
| Golomb HM, Alimena G, Rowley JD, Vardiman JW, Testa JR, Sovik C |
| Blood. 1982 ; 60 (2) : 404-411. |
| PMID 7093525 |
| Cytogenetics of secondary myelodysplasia (sMDS) and acute nonlymphocytic leukemia (sANLL). |
| Johansson B, Mertens F, Heim S, Kristoffersson U, Mitelman F |
| European journal of haematology. 1991 ; 47 (1) : 17-27. |
| PMID 1868912 |
| Cytokine modulation of the susceptibility of acute T-lymphoblastic leukemia cell lines to LAK activity. |
| Cesano A, Clark SC, Santoli D |
| Leukemia : official journal of the Leukemia Society of America, Leukemia Research Fund, U.K. 1993 ; 7 (3) : 404-409. |
| PMID 8445946 |
| Childhood monosomy 7: epidemiology, biology, and mechanistic implications. |
| Luna-Fineman S, Shannon KM, Lange BJ |
| Blood. 1995 ; 85 (8) : 1985-1999. |
| PMID 7718870 |
| Cytogenetic clonality analysis in myelodysplastic syndrome: monosomy 7 can be demonstrated in the myeloid and in the lymphoid lineage. |
| van Lom K, Hagemeijer A, Smit E, H§hlen K, Groeneveld K, Lwenberg B |
| Leukemia : official journal of the Leukemia Society of America, Leukemia Research Fund, U.K. 1995 ; 9 (11) : 1818-1821. |
| PMID 7475268 |
| Molecular definition of a narrow interval at 7q22.1 associated with myelodysplasia. |
| Johnson EJ, Scherer SW, Osborne L, Tsui LC, Oscier D, Mould S, Cotter FE |
| Blood. 1996 ; 87 (9) : 3579-3586. |
| PMID 8611680 |
| Cytogenetic and molecular delineation of a region of chromosome 7 commonly deleted in malignant myeloid diseases. |
| Le Beau MM, Espinosa R 3rd, Davis EM, Eisenbart JD, Larson RA, Green ED |
| Blood. 1996 ; 88 (6) : 1930-1935. |
| PMID 8822909 |
| Deletion of the acetylcholinesterase locus at 7q22 associated with myelodysplastic syndromes (MDS) and acute myeloid leukaemia (AML). |
| Stephenson J, Czepulkowski B, Hirst W, Mufti GJ |
| Leukemia research. 1996 ; 20 (3) : 235-241. |
| PMID 8637218 |
| Molecular cytogenetic delineation of deletions and translocations involving chromosome band 7q22 in myeloid leukemias. |
| Fischer K, Frhling S, Scherer SW, McAllister Brown J, Scholl C, Stilgenbauer S, Tsui LC, Lichter P, Dhner H |
| Blood. 1997 ; 89 (6) : 2036-2041. |
| PMID 9058725 |
| Monosomy 7 and 7q--associated with myeloid malignancy. |
| Johnson E, Cotter FE |
| Blood reviews. 1997 ; 11 (1) : 46-55. |
| PMID 9218106 |
| Evidence for two molecular steps in the pathogenesis of myeloid disorders associated with deletion of chromosome 7 long arm. |
| Kiuru-Kuhlefelt S, Kristo P, Ruutu T, Knuutila S, Kere J |
| Leukemia : official journal of the Leukemia Society of America, Leukemia Research Fund, U.K. 1997 ; 11 (12) : 2097-2104. |
| PMID 9447826 |
| Molecular anatomy of chromosome 7q deletions in myeloid neoplasms: evidence for multiple critical loci. |
| Liang H, Fairman J, Claxton DF, Nowell PC, Green ED, Nagarajan L |
| Proceedings of the National Academy of Sciences of the United States of America. 1998 ; 95 (7) : 3781-3785. |
| PMID 9520444 |
| Cytogenetic abnormalities in primary myelodysplastic syndrome are highly predictive of outcome after allogeneic bone marrow transplantation. |
| Nevill TJ, Fung HC, Shepherd JD, Horsman DE, Nantel SH, Klingemann HG, Forrest DL, Toze CL, Sutherland HJ, Hogge DE, Naiman SC, Le A, Brockington DA, Barnett MJ |
| Blood. 1998 ; 92 (6) : 1910-1917. |
| PMID 9731047 |
| Neutrophil dysplasia is not a specific feature of the abnormal chromosomal clone in myelodysplastic syndromes. |
| Hast R, Eriksson M, Widell S, Arvidsson I, Bemell P |
| Leukemia research. 1999 ; 23 (6) : 579-584. |
| PMID 10374851 |
| Allelotyping of acute myelogenous leukemia: loss of heterozygosity at 7q31.1 (D7S486) and q33-34 (D7S498, D7S505). |
| Koike M, Tasaka T, Spira S, Tsuruoka N, Koeffler HP |
| Leukemia research. 1999 ; 23 (3) : 307-310. |
| PMID 10071086 |
| Contributor(s) |
| Written | 06-1999 | François Desangles |
| Citation |
| This paper should be referenced as such : |
| Desangles F . -7/del(7q) in adults. Atlas Genet Cytogenet Oncol Haematol. June 1999 . URL : http://AtlasGeneticsOncology.org/Genes/del7qID1093.html |
| © Atlas of Genetics and Cytogenetics in Oncology and Haematology | indexed on : Sat Dec 6 18:01:48 2008 |
For comments and suggestions or contributions, please contact us