Gene findings revealing reasons for neurobla...( Two new studies from The Children's ...),Health

Two new studies from The Children's Hospital of Philadelphia advance the search for genetic events that result in neuroblastoma, a puzzling, often-deadly type of childhood cancer.

Originating in the peripheral nervous system, neuroblastoma is the most common solid cancer of early childhood and causes 15 percent of all childhood cancer deaths.

"Only two years ago we had very little idea of what causes neuroblastoma," said study leader John M. Maris, M.D., chief of Oncology and director of the Cancer Center at The Children's Hospital of Philadelphia. "Now we have unlocked a lot of the mystery of why neuroblastoma arises in some children and not in others."

In the largest gene study to date in pediatric oncology, Maris's study team performed a genome-wide association study to discover that common variants in the gene BARD1 increase a child's susceptibility to a high-risk form of neuroblastoma.

A second genome-wide study found that a copy number variation (CNV)a missing stretch of DNAalong a structurally weak location on chromosome 1 plays an important role in the development of neuroblastoma. Although CNVs have received much attention from genetics researchers over the last several years, this study was the first example of a specific CNV that predisposes people to cancer.

The BARD1 study was published online in Nature Genetics on May 3, while the CNV study appears in tomorrow's issue of Nature. The researchers made use of highly automated gene-analyzing technology at the Center for Applied Genomics at Children's Hospital, directed by Hakon Hakonarson, M.D., Ph.D., a co-author of both studies. They used specimens collected from around the world through the Children's Oncology Group.

The BARD1 gene had already attracted attention from oncology researchers because it is associated with the gene BRCA1, which was the first discovered familial breast cancer gene. "Researchers have suspected that var
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