First-ever link between missing DNA and cancer: study

Here Two More Study!!

Genome-wide association study

It has been widely suspected that CNVs could lead to cancerous tumours, but evidence had remained elusive.

Using powerful computers, Maris compared long stretches of DNA in cancer patients and healthy persons to conduct what is called a genome-wide association study.

The technique has, over the last decade, uncovered hundreds of links between disease and DNA, but was designed to hunt for a different kind of genetic glitch, not copy variation.

"The achievement here was proving the hypothesis that CNVs do, indeed, predispose to this paediatric cancer," Maris said in a phone interview.

"We can infer that it's not just going to be true for neuroblastoma. My expectation is that there will be many reports following on this of similar types of associations in other cancers," he said.

The study also highlights the fact that, when it comes to disease, including cancer, there is no hard-and-fast definition of what is hereditary.

Mendelian diseases

Only a handful of conditions - the so-called Mendelian diseases, such as muscular dystrophy and cystic fibrosis - are caused by mutations in a single gene.

Most are triggered by a complex web of genetic and environmental factors that are difficult to tease apart.

"Like all human cancers, a small percentage of neuroblastoma runs in families - usually one or two percent - and the rest seemingly occur by chance," explained Maris.

"The genome-wide association field is showing that it is not chance. There actually is a genetic susceptibility, but it takes a perfect storm of inheriting the right mix of these risk factors from Mom and Dad."

With some variation worldwide, approximately 100 in a million children under 15 develop neuroblastoma. Incidence decreases with age, and is up to 10 times higher among infants than young teenagers.