| Disease |
only found so far in M7 AML (acute megakaryocytic leukaemia); not found in Down syndrome (DS), and yet, DS is a disease with highly elevated risk of M7 (see leukaemia and Down Syndrome); misdiagnoses of a solid tumour have been documented |
| Phenotype / cell stem origin |
megakaryocytic |
| Etiology | no known toxic exposure |
| Epidemiology | about 40 known cases; 0% to 3% of paediatric AML; 70 to 100% of infants M7; age: infants: median age 4 mths; 20% are < 1mth; 80% are < 1 yr; 95% are < 2 yrs; sex ratio: 15M/24F (non significant) |
| Clinics | no preceeding myelodysplasia, and no history of transient leukemoid reaction; prominent organomegaly; blood data: moderate WBC; thrombocytopenia; myelofibrosis and fibrosis of other organs |
| Cytology | platelet-specific markers: platelet-peroxidase by electron microscopy, or platelet glycoproteins IIb/IIIa (CD41) or IIIa (CD61) |
| Treatment | bone marrow transplantation is indicated |
| Prognosis | complete remission in only 50% of cases; median survival: 8 months; a few long survivors; absence of a prognostic indicator |
| Additional anomalies | 60% of cases (mostly patients under 6 mths of age) have the t(1;22) as a single anomaly; the remaining third of cases (mainly patients above the age of 6 mths) exhibit complex and hyperploid clones, with a highly monomorph pattern: +2, +19, +der(1)t(1;22), +6, +21 were found in more than 50% of cases each, +10, +7, +15, +18, +8, +20, del(1p), +4, +9, +14, +17, add(21p) are also recurrent; survival was equivalent in cases with or without a complex karyotype; the frequent presence of an additional der(1) indicates that the crucial event is likely to lie on the der(1)t(1;22) |
| Variants | 2 cases of complex t(1;22) with a third chromosome have been described |
| Nineteen cases of the t(1;22)(p13;q13) acute megakaryblastic leukaemia of infants/children and a review of 39 cases: report from a t(1;22) study group. |
| Bernstein J, Dastugue N, Haas OA, Harbott J, Heerema NA, Huret JL, Landman-Parker J, LeBeau MM, Leonard C, Mann G, Pages MP, Perot C, Pirc-Danoewinata H, Roitzheim B, Rubin CM, Slociak M, Viguie F |
| Leukemia : official journal of the Leukemia Society of America, Leukemia Research Fund, U.K. 2000 ; 14 (1) : 216-218. |
| PMID 10637500 |
| |
| The t(1;22) (p13;q13) is nonrandom and restricted to infants with acute megakaryoblastic leukemia: a Pediatric Oncology Group Study. |
| Carroll A, Civin C, Schneider N, Dahl G, Pappo A, Bowman P, Emami A, Gross S, Alvarado C, Phillips C |
| Blood. 1991 ; 78 (3) : 748-752. |
| PMID 1859887 |
| |
| Acute megakaryocytic leukemia with the t(1;22)(p13;q13). |
| Lion T, Haas OA |
| Leukemia & lymphoma. 1993 ; 11 (1-2) : 15-20. |
| PMID 8220150 |
| |
| Fusion of two novel genes, RBM15 and MKL1, in the t(1;22)(p13;q13) of acute megakaryoblastic leukemia. |
| Ma Z, Morris SW, Valentine V, Li M, Herbrick JA, Cui X, Bouman D, Li Y, Mehta PK, Nizetic D, Kaneko Y, Chan GC, Chan LC, Squire J, Scherer SW, Hitzler JK |
| Nature genetics. 2001 ; 28 (3) : 220-221. |
| PMID 11431691 |
| |
| Clinical and prognostic significance of chromosomal abnormalities in childhood acute myeloid leukemia de novo. |
| Martinez-Climent JA, Lane NJ, Rubin CM, Morgan E, Johnstone HS, Mick R, Murphy SB, Vardiman JW, Larson RA, Le Beau MM |
| Leukemia : official journal of the Leukemia Society of America, Leukemia Research Fund, U.K. 1995 ; 9 (1) : 95-101. |
| PMID 7845034 |
| |
| Involvement of a human gene related to the Drosophila spen gene in the recurrent t(1;22) translocation of acute megakaryocytic leukemia. |
| Mercher T, Coniat MB, Monni R, Mauchauffe M, Nguyen Khac F, Gressin L, Mugneret F, Leblanc T, Dastugue N, Berger R, Bernard OA |
| Proceedings of the National Academy of Sciences of the United States of America. 2001 ; 98 (10) : 5776-5779. |
| PMID 11344311 |
| |
