Masked hypodiploidy: hypodiploid acute lymphoblastic leukemia (ALL) mimicking hyperdiploid ALL in children: A report from the Children's Oncology Group

Hyperdiploidy with greater than 50 chromosomes is usually associated with favorable prognosis in pediatric acute lymphoblastic leukemia (ALL), whereas hypodiploidy with ≤43 chromosomes is associated with extremely poor prognosis. Sometimes, hypodiploidy is “masked” and patients do not have a karyotypically visible clone with ≤43 chromosomes. Instead, their abnormal karyotypes contain 50–78 or more chromosomes from doubling of previously hypodiploid cells. When the hypodiploid and doubled hyperdiploid clones are both present, patients can be identified by traditional test methods [karyotype, DNA Index (DI), fluorescence in situ hybridization (FISH)], but the incidence of masked hypodiploid cases in which only the doubled clone is visible is unknown.

Source: Cancer Genetics and Cytogenetics - July 29, 2019 Category: Genetics & Stem Cells Authors: Andrew J Carroll, Mary Shago, Fady M Mikhail, Susana C Raimondi, Betsy A Hirsch, Mignon L Loh, Elizabeth A Raetz, Michael J Borowitz, Brent L Wood, Kelly W Maloney, Leonard A Mattano, Eric C Larsen, Julie Gastier-Foster, Eileen Stonerock, Denise Ell, Sami Source Type: research