St. Jude Children's Research Hospital scientists have identified inherited variations in two genes that can lead to childhood acute lymphoblastic leukemia (ALL), a common childhood cancer.
The finding also includes a gene that may help predict drug response.
Dr. Mary Relling, St. Jude Pharmaceutical Sciences chair and the paper's senior author, estimated that individuals who inherited variations in the genes, known as ARID5B and IKZF1, were almost twice as likely to develop ALL.
Even then, she said that the risk remains low.
"The genetic variations alone are not enough to cause the cancer. Like all cancers, pediatric ALL is a multi-factor disease," Nature magazine quoted her as saying.
"But these findings may give us a handle on the mechanism of the disease and drug responsiveness to it," she added.
The inherited variations in ARID5B might also influence patient response to chemotherapy, particularly to the drug methotrexate.
"We found this same inherited variation also affected accumulation of the drug in leukemia cells. It accumulates better. That allows us to use a lower dose and still cure the leukemia," Relling said.
"These findings may identify a new marker that could be used to help decide on doses of methotrexate in patients with varying ARID5B status."
In the study involving of 441 children with ALL, the researchers found that both ARID5B and IKZF1 play important roles in normal development of lymphoid or white blood cells.
The study has been published in the journal Nature Genetics.