Extra Chromosomes In Childhood Leukemia Show Pattern

Armen Hareyan's picture

Childhood Leukemia

A new study of childhood acute leukemia shows that the extra numbers of specific chromosomes present in the diseased cells arise according to a predictable pattern.

Chromosomes carry the genes in all cells, which normally have 46 chromosomes.

This study examined cancer cells from children with acute lymphoblastic leukemia (ALL). These leukemia cells can have 80 or more chromosomes.

This study found that the number of chromosomes in the diseased cells predicts which chromosomes are present as extras in particular patients.


These findings may help improve the understanding of the early events that cause this leukemia. In particular, they may shed light on how the abnormal distribution of chromosomes occurs during the initial cell division.

They may also help explain why children with leukemia cells that have 51 or more chromosomes generally respond better to treatment than those with 50 or fewer chromosomes.

The research was sponsored by the Children's Oncology Group and was published online in the journal Genes, Chromosomes and Cancer.

"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 this disease," says first author Nyla A. Heerema, professor of pathology at the Ohio State University Medical Center.

"We don't yet know what that might be, but this provocative finding may direct us toward an answer," says Heerema, who is also a researcher with Ohio State's Comprehensive Cancer Center.

Overall, Heerema says, "Our results indicate that the total number of chromosomes can predict which chromosomes are present as extras in these cases of ALL. Next, we need to learn why this pattern occurs and whether it can help guide decisions about therapy."