17p- syndrome arising from a novel dicentric translocation in a patient with acute myeloid leukemia.
The cytogenetic contribution to the poor prognosis when myelodysplastic syndrome (MDS) progresses to acute myeloid leukemia (AML) is not well understood. We present a 66-year-old male who had thrombocytopenia with dysplastic features in peripheral blood neutrophils (hypogranular, hyposegmented neutrophils) comprising the Pelger-Huet anomaly, increased blasts in the marrow, and markers consistent with AML. Diagnostic marrow cytogenetics showed a complex karyotype including del(5q), a novel unbalanced dicentric translocation, t(17;20), resulting in both del(20q) and del(17p). Fluorescence in situ hybridization (with probe TP53) showed deletion of 17p13 on the dicentric chromosome, completing the criteria for the 17p- syndrome. Fluorescence in situ hybridization with probes for two tumor suppressor genes on chromosome 5q also showed deletion (CSF1R [at 5(q33.2-q33.4) and EGR-1 [5(q31-q32)]). Remission was difficult to achieve and cytogenetic relapse occurred 6 months postdiagnosis, and clinical relapse approximately one month later. Our case provides a novel mechanism for the 17p- syndrome, and highlights the difficulty of attributing prognostic significance to a particular cytogenetic abnormality in AML.
Watson
N
N
Department of Cytogenetics, Royal Alexandra Hospital for Children, Westmead, Australia.
Dunlop
L
L
Robson
L
L
Sharma
P
P
Smith
A
A
D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002886:Chromosomes, Human, Pair 17; D002890:Chromosomes, Human, Pair 20; D005500:Follow-Up Studies; D006801:Humans; D007621:Karyotyping; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D008297:Male; D013577:Syndrome; D014178:Translocation, Genetic