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.”