BOSTON, Jan. 4 (UPI) -- A genetic mutation appears to be responsible for up to 30 percent of the cases of pediatric kidney cancer, U.S. doctors said Thursday.
Doctors at Massachusetts General Hospital Cancer Center said Thursday the suspect gene associated with development of Wilms tumor is located on the sex-determining X chromosome.
"This is the first X chromosome gene directly implicated as a tumor suppressor," said Daniel Haber, director of the Cancer Center. His study appears in early online release in the journal Science.
Also called nephroblastoma, Wilms tumor develops in one out of 10,000 children and is usually treated successfully with surgery and chemotherapy. Mutations in a gene called WT1, first identified in 1990, cause about 5 percent of cases, and a few other genes are associated with rare syndromes that can include Wilms tumor.
Those with a family history of the disease have an increased risk of developing the cancer in both kidneys.
Haber and colleagues analyzed tumor samples from 82 patients to search for additional genetic abnormalities. Genome screening and sequencing tests showed that nearly 30 percent of the samples had either deletions or mutations in the same area of the X chromosome, indicating a new cancer gene that the researchers have named WTX. In samples from female patients, mutated copies of WTX were found only on the active copy of the X chromosome.
"Males have only one X chromosome, so for them a single mutation can silence the gene and cause a tumor," Haber explained. "Females have two X chromosomes, but one is inactivated during normal development. We showed that mutations specifically occur on the active X in female Wilms patients, so it takes a single genetic event to inactivate WTX in either males or females. That's in contrast to other tumor suppressor genes, which only can be inactivated by independent mutations affecting both copies of the gene."
