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Johns Hopkins Scientists Present Findings at the American Society of Human Genetics Meeting - 10/08/2015

Johns Hopkins Scientists Present Findings at the American Society of Human Genetics Meeting

Release Date: October 8, 2015

American Society of Human Genetics 2015
Oct. 6–10, 2015
Baltimore, Maryland

Friday, Oct. 9, 12:45–2:15 p.m.
Convention Center, Room 337, Level 3
Ada Hamosh, Carol Bocchini, Joanna Amberger, Nara Sobreira, Francois Schiettecatte and Alan Scott

OMIM’s 50th Anniversary: Suggestions for the Future

The 2015 American Society of Human Genetics meeting marks the start of a one-year celebration of the 50th anniversary of the Online Mendelian Inheritance in Man knowledgebase. There will be an open forum for community feedback and discussion of future funding mechanisms.

OMIM grew out of Mendelian Inheritance in Man, a catalog of human genes and genetic disorders created and maintained by Victor McKusick. OMIM now contains information on over 15,000 human genes and almost 8,000 genetic conditions. In addition to its use as a foundational resource for human genetics, OMIM provides topical links to over 50 other Web-based resources and enables researchers to find collaborators. Its users include clinicians and basic researchers, academic and industry scientists, bioinformaticians, and teachers and students of these disciplines. In the last year alone, OMIM had over 5.5 million visitors to its website from every country in the world.
Ada Hamosh, M.D., M.P.H., OMIM’s scientific director, will be available to discuss the future of this pillar in the genetics community.

Thursday, Oct. 8, 5–5:15 p.m.
Holiday Ballroom 1, 2nd Floor; Hilton Baltimore
Kristin Bigos, M. Ryan Haynes, Danny Chen and Daniel Weinberger

Genetics Determines Effectiveness of Antipsychotic Drug

Researchers at Johns Hopkins Medicine and the Lieber Institute for Brain Development identified two genes that determine the effectiveness of the schizophrenia drug olanzapine in patients of Caucasian and African-American descent. Results from this study suggest a way for doctors to find out in advance which patients are most likely to benefit from the drug or at which dose would be most helpful. In one trial of olanzapine, over 60 percent of patients discontinued the drug because of ineffectiveness or side effects. To identify genetic factors that control the body’s response to the drug, researchers collected blood samples from 157 Caucasian and 73 African-American patients prescribed olanzapine to treat symptoms of schizophrenia in a clinical trial. The researchers measured how quickly the drug disappeared from the blood after administration and compared these results to genomewide association data collected from the trial. The quicker the drug clears from the blood, the less of the drug there is available to effectively treat the symptoms of schizophrenia. In Caucasian patients, they found the drug cleared the fastest in patients with a single mutation in the gene CSMD1. In African-American patients, a single mutation near the gene TMCO4 resulted in faster clearance of the drug. The researchers have also identified many other single mutations in other genes that are associated with differences in this drug’s clearance. They hope that one day, a more individualized, genetic approach can be used to treat patients for mental disorders like schizophrenia.

Wednesday, Oct. 7, 11 a.m.
Room 307, Level 3, Convention Center

Special Diet Found to Alleviate Inherited Form of Intellectual Disability in Mice

Studying mice with a genetic change similar to what is found in Kabuki syndrome, an inherited disease of humans, Johns Hopkins researcher Hans Bjornsson, M.D., Ph.D., reports that his team has used a low-carbohydrate diet and a naturally occurring molecule with the same physical effect to “open up” DNA and improve mental function. Along with providing a potential treatment for the intellectual disability seen in Kabuki syndrome, the study’s findings also suggest a new way of thinking about a category of genetic diseases known as Mendelian disorders of the epigenetic machinery, the researchers say. In these disorders, a genetic mutation causes errors in the way DNA or associated proteins are modified, which in turn affects the rate at which DNA makes other proteins. In the case of a Kabuki syndrome-like condition in mice, the researchers found that those errors lead to a persistent but treatable decrease in new cell growth in one part of the brain. Their study adds to the growing evidence that intellectual disability could in some cases be reversible. (See full press release for more details)

Wednesday, Oct. 7, 12:30 p.m.
Ballroom I, Level 4, Convention Center

Dawn of the Regulatory Age: Noncoding DNA Yields More Causes of Genetic Disease

Disease gene hunters usually focus on the regions of the genome known as exons, which form the genetic blueprints of proteins. In recent decades, it’s become clear that the DNA letters located between genes play a critical regulatory role, determining whether proteins get made. But exons retain their starring role in disease research. Now, however, as Sumantra Chatterjee, Ph.D., reports newly found genetic contributors to Hirschsprung’s disease suggest that increased research on noncoding DNA could help complete the map of genetic causes of many complex diseases. The research group compared the genetic markers of more than 350 people with Hirschsprung’s disease and more than 700 healthy controls to find single-letter changes in DNA near Ret that appeared to be associated with the disease. In the lab, they studied how those genetic variations affected DNA’s ability to bind proteins that lead to gene expression. They also genetically modified mice to have similar changes to see what the effects would be. Chatterjee is expected to report that the team identified three common variants that, in combination, raise the odds of having Hirschsprung’s disease by fourfold compared with people with none of the variants.
(See full press release for more details)