RICHMOND, Calif., July 17, 2013 /PRNewswire/ -- Sangamo BioSciences, Inc. (Nasdaq: SGMO) announced today the publication of groundbreaking research using zinc finger DNA-binding protein (ZFP) technology to insert a gene that permanently "silences" the extra copy of chromosome 21, which is the root cause of Down syndrome (DS). This advance, accomplished in induced pluripotent stem cells (iPSCs) derived from DS patients, provides a model to study the basic biology of DS which may enable the development of drugs that can potentially rebalance the cellular processes and pathologies that are impacted by this disorder. (Logo: http://photos.prnewswire.com/prnh/20130102/SF35903LOGO) The work was led by the laboratory of Jeanne Lawrence, Ph.D., interim chair and professor of cell & developmental biology at the University of Massachusetts Medical School, in collaboration with Sangamo scientists and was published as an Advance Online Publication in Naturehttp://dx.doi.org/10.1038/nature12394. "Until now our ability to correct cells carrying a chromosomal abnormality, by specifically silencing, or shutting down, expression of essentially all genes across a chromosome of our choosing was outside the realm of possibility," said Dr. Lawrence. "However, this goal has been realized by using ZFNs to introduce, into a defined site in chromosome 21, a copy of a gene that normally functions to shut down the extra copy of the X chromosome in females. This provides a means to understand the cellular pathologies of DS, important for development of therapeutics, and also provides a needed model to study human chromosome inactivation." Down syndrome, or Trisomy 21, is a genetic condition in which a person has a third copy of chromosome 21 giving them a total of forty-seven chromosomes instead of the usual forty-six. DS is the leading genetic cause of intellectual disabilities. Individuals with DS also have a higher risk for many conditions, including congenital heart defects, hematopoietic disorders, and early-onset Alzheimer's disease.