Babies who develop leukemia during the first year of life appear to inherit an unfortunate combination of genetic variations that can make the infants highly susceptible to the disease, according to a new study at the School of Medicine and the University of Minnesota. The research is available online in the journal Leukemia.
Doctors have long puzzled over why it is that babies just a few months old sometimes develop cancer. As infants, they have not lived long enough to accumulate a critical number of cancer-causing mutations.
The babies appear to have inherited rare genetic variants from both parents that by themselves would not cause problems, but in combination put the infants at high risk of leukemia. These variants most often occurred in genes known to be linked to leukemia in children, said Todd E. Druley, MD, PhD, a Washington University pediatric oncologist who treats patients at St. Louis Children’s Hospital.
Only about 160 infant leukemia cases are diagnosed annually in the U.S. But unlike leukemia in older children, which often can be cured, about half of infants who develop leukemia die of the disease.
The researchers sequenced all the genes in the DNA of healthy cells from 23 infants with leukemia and their mothers. Looking at genes in the healthy cells helped the researchers understand which genetic variations were passed from a mother to her child, and by process of elimination, the scientists could determine the father’s contribution to a baby’s DNA.
Among the families studied, there was no history of pediatric cancers. Other children in the families typically don’t develop leukemia because a roll of the genetic dice likely means they did not inherit the same combination of harmful genetic changes, he added.