Chromosome number

Normal cells have 46 chromosomes (22 pairs and the sex chromosomes—XX female and XY male). Some leukemia cells contain extra copies of entire chromosomes and thus can contain more than 46 chromosomes. This is called hyperdiploidy, and it is found in approximately 27 percent of children with ALL. There are two ways to evaluate the number of chromosomes: counting them (karyotyping) or measuring the DNA content of cells (DNA index). Children with 53 or more chromosomes per cell or a DNA index greater than 1.16. have a very good prognosis. Hyperdiploidy occurs most often with B-lineage ALL.

Extra copies of particular chromosomes also seem to indicate a very favorable prognosis. Children with extra copies of chromosome 4, 10, and 17 have an especially favorable prognosis.

Approximately 6 percent of children with ALL have fewer than 45 chromosomes in the leukemia cells. This is called hypodiploidy and carries a poor prognosis.

Was this article helpful?

0 0
Confident Kids

Confident Kids

Although nobody gets a parenting manual or bible in the delivery room, it is our duty as parents to try to make our kids as well rounded, happy and confident as possible. It is a lot easier to bring up great kids than it is to try and fix problems caused by bad parenting, when our kids have become adults. Our children are all individuals - they are not our property but people in their own right.

Get My Free Ebook

Post a comment