trisomy 19

AGCOH

Trisomy 19 is frequently encountered in cases of chronic myeloid leukemia (CML) as a secondary abnormality: however, trisomy 19 rarely occurs as a sole chromosomal abnormality.

Trisomy 19 (+19) as a sole karyotypic aberration is strongly associated with myeloid disorder.

In a previously published literature review, among 31 patients with isolated +19, 25 were diagnosed with myeloid malignancy, including acute myeloid leukaemia (AML) in 14 cases and myelodysplastic syndrome (MDS) in 11 cases.

Four out of the 14 AML patients had a preceding MDS phase, with +19 appearing at the time of leukaemic transformation. None of the MDS or AML cases, however, had a history of exposure to radiotherapy and chemotherapy.

Hence isolated +19 is associated with a subgroup of de novo myeloid disorder, in which the clinical characteristics and prognostic impact require further delineation.

As a secondary or additional abnormality, +19 is frequently encountered in chronic myeloid leukaemia (CML). Though not as common as trisomy 8, i(17q) and extra Ph chromosome, +19 is nevertheless seen in up to 15% of CML patients with additional abnormalities.

Frequent gain of chromosome 19 or 19q was recently detected by comparative genomic hybridization in 4 out of 12 (33.3%) patients samples of acute megakaryoblastic leukaemia (AML-M7) and 9 out of 11 (81.8%) megakaryoblastic cell lines.

In none of the primary patient samples was the abnormality detected by G-banding analysis.

In another study on childhood and adult AML-M7, +19 was detected in 7 out of 53 patients, although as an additional abnormality in all cases.

It appears +19 may play a role in the pathogenesis of megakaryoblastic leukaemia.

Sole chromosomal abnormality in tumors

 myeloid proliferations (18594167)

• chronic myeloid leukaemia (CML)
  • As a secondary or additional abnormality, +19 is frequently encountered in chronic myeloid leukaemia (CML).
  • Though not as common as trisomy 8, i(17q) and extra Ph chromosome, +19 is nevertheless seen in up to 15% of CML patients with additional abnormalities.
• proliferative chronic myelomonocytic leukemia (16464494)
• acute myeloid leukemia minimally differentiated (18594167)
• refractory anemia with excess blasts (18594167)

 adenocarcinoma
 astrocytic tumor
 ependymoma (17626628)

Secondary abnormality

 chronic myeloid leukemia (CML)

Etiology

Isolated +19 is probably associated with de novo myeloid disorders, as none of the AML and MDS cases with this abnormality reported had a history of prior radiotherapy or chemotherapy exposure.

Prognosis

Although isolated +19 is strongly associated with myeloid disorders, most probably de novo disease, its prognostic significance requires further elucidation.

Links

 AGCOH

References

 Trisomy 19 ependymoma, a newly recognized genetico-histological association, including clear cell ependymoma. Rousseau E, Palm T, Scaravilli F, Ruchoux MM, Figarella-Branger D, Salmon I, Ellison D, Lacroix C, Chapon F, Mikol J, Vikkula M, Godfraind C. Mol Cancer. 2007 Jul 12;6:47. PMID: 17626628

 Trisomy 19 as the sole chromosomal abnormality in proliferative chronic myelomonocytic leukemia. Daskalakis M, Mauritzson N, Johansson B, Bouabdallah K, Onida F, Kunzmann R, Müller-Berndorff H, Schmitt-Gräff A, Lübbert M. Leuk Res. 2006 Aug;30(8):1043-7. PMID: 16464494

 Trisomy 19 in a patient with myelodysplastic syndrome and thrombocytosis.
Humphries JE, Wheby MS. Cancer genetics and cytogenetics. 1990 ; 44 (2) : 187-191. PMID 2297677

 Trisomy 19 as the sole chromosomal anomaly in hematologic neoplasms.
Johansson B, Billstrˆ m R, Mauritzson N, Mitelman F. Cancer genetics and cytogenetics. 1994 ; 74 (1) : 62-65. PMID 8194050

 Frequent gain of chromosome 19 in megakaryoblastic leukemias detected by comparative genomic hybridization. Alvarez S, MacGrogan D, Calasanz MJ, Nimer SD, Jhanwar SC. Genes, chromosomes & cancer. 2001 ; 32 (3) : 285-293. PMID 11579469

 Chromosome 19 abnormalities are commonly seen in AML, M7. Nimer SD, MacGrogan D, Jhanwar S, Alvarez S. Blood. 2002 ; 100 (10) : 3838-3839. PMID 12411327