Right on the tails of my last post comes ground-breaking news about identical twins: they don’t actually have identical genetics! (Darn close, but not 100% identical.)

A study by University of Alabama, Birmingham researchers challenges the long-held belief that identical twins have identical genetics. They compared the DNA of sets of twins and discovered significant copy number variation (or CNV).

…[S]ubstantial chunks of DNA sequences were missing, doubled or reversed in one of the two twins. Having chunks of DNA sequences shifted around or missing is a common genetic mutation. When first discovered, scientists thought it was inconsequential. Often it is, but researchers are beginning to learn that sometimes CNV can be a major factor in developing a disease.

This new discovery isn’t just interesting for trivia’s sake, but it holds promise for our understanding of health conditions and diseases. “Changes in CNV may tell us if a missing gene, or multiple copies of a gene, are implicated in the onset of disease,” says Carl Bruder , one of the heads of research. “If twin A develops Parkinson’s and twin B does not, the region of their genome where they show differences is a target for further investigation to discover the basic genetic underpinnings of the disease.”

UAB News Release
DNA Direct’s Alabama native son (not a twin)

Update 3/13/08: You read it here first…but the NYTimes gets the interviews with the good quotes The Claim: Identical Twins Have Identical DNA.

Tags: cnv, copy number variation, disease, genetics, genome, identical, research, twins

This entry was posted on Friday, February 15th, 2008 at 12:33 pm and is filed under Family Health & Heredity, Miscellaneous. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.