New Map of Genomic Variation Will Enable Diseas...( PHILADELPHIA July 1...),Health

PHILADELPHIA, July 15 /PRNewswire-USNewswire/ -- Genetics researchers have unveiled a powerful new resource for scientists and health providers studying human illnesses -- a reference standard of deletions and duplications of DNA found in the human genome. Drawn from over 2,000 healthy persons, the study provides one of the deepest and broadest sets of copy number variations (CNVs) available to date, along with a new research tool for diagnosing and identifying genetic problems in patients.

A team from The Children's Hospital of Philadelphia published its high-resolution map and analysis of CNVs in the human genome in the July 10 online edition of the journal Genome Research.

In contrast to alterations to a single base of DNA, which are single nucleotide polymorphisms, or SNPs, often referred to as "snips," CNVs are larger variations in DNA structure. As changes to a single DNA letter, SNPs might be considered misspellings or alternate spellings of a word, while CNVs are losses of whole phrases, paragraphs or even pages (deletions), or are repeated sections (duplications). Some CNVs are inserted stretches of DNA from other parts of the genome. Both SNPs and CNVs contribute to genetic diversity and disease by changing the action of genes for which DNA carries coded instructions.

"We all carry a number of these variations in our own genomes," said study co-leader Peter S. White, Ph.D., a molecular geneticist and director of the Center for Biomedical Informatics at Children's Hospital. "Some CNVs contribute to a disorder, but most of them do not, and it is often challenging to determine which are important. One approach is to compare CNVs in healthy individuals to those in patients with a disease, to find those CNVs that seem to occur primarily in people with a certain disease. Our map provides a large and uniform baseline standard to indicate which CNVs repre
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