A team of researchers from Lund University in Sweden has discovered two new types of B-cell precursor acute lymphoblastic leukemia (BCP ALL) in children.

Previously, there were six major types pediatric lymphoblastic leukemia. This type of leukemia is rare but is the most common form of cancer in children. At present, acute lymphoblastic leukemia is highly treatable. However, heavy interventions are required and there is also a high risk of potential side effects.

"Like all types of cancer, childhood leukaemia is caused by genetic mutations in normal cells, which are then transformed into cancer cells. Finding the critical mutations in the diseased cells are an important condition for understanding the mechanisms of the disease and ultimately discovering new therapies," Thoas Fioretos, professor and senior consultant at the Division of Clinical Genetics, and Principal investigator of the project, explained in a statement.

For their study, researchers analyzed the genome of leukemia cells from more than 200 children using next-generation sequencing technology (NGS). NGS made it easier for the researchers to examine changes that occur in cancer cells in greater detail, leading to the discovery of two new types of leukemia in children.

Their findings, published in the journal Nature Communications, revealed two types of new leukemia, which they called "DUX4-rearranged" and "ETV6/RUNX1-like". The first type, DUX4-rearranged, occurs when the inactive DUX4 in blood cells were activated when the gene is relocated in the genome. On the other hand, the second type resembles a previously known type of childhood leukemia, but is caused by other genetic mutations.

These new types of leukemia represent 10 percent of all childhood leukemia. The other six previously discovered type of childhood leukemia include ETV6-RUNX1, TCF3-PBX1, TCF3-HLF, high hyperdiploidy (51-67 chromosomes), hypodiploidy (<45 chromosomes) or MLL (also known as KMT2A).

Knowing the type of leukemia a child has is very important, in order to adapt the treatment according to the severity of each case, and to detect possible relapse. Researchers hope that their findings can lead to improved diagnosis and monitoring of childhood leukemia, and ultimately new forms of treatment.