Juvenile Myelomonocytic Leukemia: A rare form of childhood leukemia in which cancer cells often spread into tissues such as the skin, lung, and intestines.
Karyotype: The systematic arrangement, using images, of the 46 human chromosomes of a cell in 22 matched pairs (maternal and paternal member of each pair) by length from longest to shortest and other features. These 22 pairs are referred to as autosomes. The sex chromosomes are shown as a separate pair (either XX or XY).
Karyotypic Abnormality: Abnormality in the number, form or structure of chromosomes. Particular abnormalities are associated with particular sub-types of leukemia. Loss of whole chromosomes or parts of chromosomes (deletions), extra chromosomes, switches of pieces of chromosomes from one to another (translocations) are examples of such abnormalities. A minus sign is used to indicate a deletion. For example, “-7“ represents the loss of chromosome 7. This abnormality can also be referred to as monosomy 7. The chromosomes involved in a translocation are in brackets separated by a semicolon. The designation “t(8;21)” indicates that a translocation of a piece of chromosome 8 was exchanged for a piece of chromosome 21.