Genetic variants inherited from both parents increase infants' leukemia risk

Leukemia developed during the first year of life may be the result genetic variations derived from both parents, reveals a recent study by the researchers at the Washington University School of Medicine.

Around 160 infants in the United States are diagnosed with leukemia every year. Given the patients' young age, other risk factors are simply implausible, the researchers note.

"Parents always ask why their child has developed leukemia, and unfortunately we have had few answers," Todd Druley, the lead author of the study, said in a news release. "Our study suggests that babies with leukemia inherit a strong genetic predisposition to the disease."

According to the researchers, some genetic variants derived from both parents, when paired, can increase an infant's risks. Such variants usually occur in genes related to leukemia.

The researchers examined the genes in the DNA of the healthy cells in 23 infants with leukemia along with their mothers' to find the genetic variants passed on to the infants. Excluding the maternal factors helped the researchers to identify the genetic variants derived from the fathers that may have contributed to the disease. Meanwhile, the researchers also studied the DNA of 25 healthy children.

"We sequenced every single gene and found that infants with leukemia were born with an excess of damaging changes in genes known to be linked to leukemia," Druley said. "For each child, both parents carried a few harmful genetic variations in their DNA, and just by chance their child inherited all of these changes."

Still, the researchers are doubtful that the inherited variations are the sole reason behind the cancer, instead hypothesizing that additional genetic errors in a child's bone marrow are needed for the disease to take root so quickly.

In the past, researchers believed that children living within 600 meters of overhead powerlines faced an increased risk of developing leukemia - an assertion that was recently refuted in a study conducted by Oxford's Childhood Cancer Research Group.