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Archive - Oct 22, 2013

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Gene-Silencing Strategy Opens New Path to Understanding Down Syndrome

The first evidence that the underlying genetic defect responsible for trisomy 21, also known as Down syndrome, can be suppressed in laboratory cultures of patient-derived stem cells was presented today (October 22) at the opening of the American Society of Human Genetics (ASHG) 2013 annual meeting in Boston, running through October. The ASHG annual meeting is the world's largest gathering of human genetics professionals and a forum for renowned experts in the field.People with Down syndrome are born with an extra chromosome 21, which results in a variety of physical and cognitive ill effects. In laboratory cultures of cells from patients with Down syndrome, an advanced genome editing tool was successfully used to silence the genes on the extra chromosome, thereby neutralizing it, said Jeanne Lawrence, Ph.D., Professor of Cell & Developmental Biology at the University Massachusetts Medical School, Worcester, Massachusetts. Dr. Lawrence and her team compared trisomic stem cells derived from patients with Down syndrome, in which the extra chromosome 21 was silenced, to identical cells from patients that were untreated. The researchers identified defects in the proliferation, or rapid growth, of the untreated cells and the differentiation, or specialization, of untreated nervous system cells. These defects were reversed in trisomic stem cells in which the extra chromosome 21 was muted. “Silencing of trisomy 21 by manipulation of a single gene in living cells in laboratory cells surmounts the first major obstacle to development of potential ‘chromosome therapy,’” said Dr. Lawrence, whose presentation today provided an update to the results that she and her colleagues reported earlier this year in the journal Nature (Jiang et al. 2013). In her ASHG presentation, Dr.

Opportunities and Risks of Personal Genomics Are Key Topics of Sunday’s Session of the World Congress of Psychiatric Genetics in Boston

Sunday’s (October 20) portion of the five-day 2013 XXIst World Congress of Psychiatric Genetics opened with a plenary session on the “Opportunities and Risks Associated with Personal & Clinical Genomics.” The format was a panel presentation chaired by Robert C. Green, M.D., M.P.H., Associate Professor of Medicine in the Division of Genetics at Brigham and Women’s Hospital and Harvard Medical School, Associate Director for Research at Partners Health Care for Personalized Genetic Medicine, and Director of Genes2People (GTP). The four distinguished panelists were Paul Appelbaum, M.D., Professor of Psychiatry, Medicine, & Law and Director of the Division of Law, Ethics, and Psychiatry in the Department of Psychiatry at Columbia University; Atul Butte, M.D., Ph.D., Chief of the Division of Systems Medicine and Associate Professor of Pediatrics, Medicine, and Computer Science at Stanford University and Lucile Packard Children's Hospital, and a co-founder of Personalis, a contract research organization and genome-scale diagnostics services company pioneering genome-guided medicine; A. Cecile Janssens, Ph.D., Professor at Emory University in Atlanta: and Uta Francke, M.D., Professor of Genetics and Pediatrics at Stanford School of Medicine, past President of the American Society of Human Genetics, and Senior Medical Director of the personal genomics company 23andMe. Dr. Green began by discussing the purposes of genetic testing: confirmation, diagnosis of mysterious diseases, risk profiling, and research. He also stressed context: medical versus consumer interest; clinical or research; pre-conception, pre-natal, pediatric or adult; various degrees of patient education; no results and anticipated results; and incidental findings.

Identification of Over 100 Schizophrenia-Associated SNPs and Certain Autism-Associated Rare Variants Reported at World Congress of Psychiatric Genetics in Boston

Today (Monday, October 21) was the last day of the five-day 2013 XXIst World Congress of Psychiatric Genetics in Boston and the tremendous success of the meeting and the enormous progress that has recently been made were remarked upon in a comment to BioQuick by Tom Insel (photo), M.D., Director of the National Institute of Mental Health (NIMH) since 2002. “This is a rapidly moving field. Five years ago, we had too few disease-associated variants. Now, perhaps, we have too many. At this meeting, we have heard reports of the identification of over 100 schizophrenia-associated SNPs, some overlapping with bipolar disorder. This is huge. In addition, we have heard about the identification of several rare variants associated with autism and intellectual disability. This is also huge,” Dr. Insel said. Many other new and exciting discoveries were described at the Congress and virtually all of the attendees would agree with Olli Pietilainen, Ph.D., from the Institute for Molecular Medicine at the University of Finland, and presenter of his group’s identification of a gene deletion associated with schizophrenia and intellectual disability, who commented to BioQuick that this was “absolutely the best of the many psychiatric congresses I have attended.” In keeping with the extremely high quality of the entire meeting. the final day’s opening plenary session featured lively presentations and a panel discussion involving four of the world leaders in their specialties, along with interactive audience participation on two questions--(1) how the field could continue the process of genetic discovery, and (2) what are the next steps to achieve biological understanding and translation of discoveries into the clinic.