Childhood acute lymphoblastic leukemia (ALL) is being studied in a way to examine the chromosomes present in the diseased cells. Extra numbers of specific chromosomes are present and can arise according to a predictable pattern.

What does this mean? Our chromosomes carry the genes in all cells, which normally have 46 chromosomes. The ALL cells that are being studied can have more than 80 chromosomes.

This could help to understand what early events can cause this type of leukemia. The researchers also want to understand why children with ALL that have 51 or more chromosomes generally respond better to treatment than those with 50 or fewer chromosomes.

One of the authors of the study, Nyla A. Heerema, professor of pathology, states "The fact that an excess of certain chromosomes is associated with the particular overall number of chromosomes tells us that something significant happens when that first abnormal cell divides and initiates the disease"

Researchers are trying to figure out why these certain patterns occur and whether it can help guide decisions about therapy.