Daily Archives: April 17, 2014

Down Syndrome Cause Revised by Study on Genome Effects

Posted: April 17, 2014 at 3:44 pm

Symptoms of Down syndrome are produced by gene impairments across every chromosome, not just one, according to a study that may bring new understanding to the most common genetic cause of intellectual disability.

Down syndrome occurs when there is an extra copy of chromosome 21, a condition called trisomy 21. In a study of twins, where only one had Down syndrome, a genomic analysis found that gene expression in the affected sibling had been altered throughout the genome.

Researchers have presumed for decades that Down syndrome is mainly caused by the overabundance of effects of chromosome 21 genes. The findings, published today in the journal Nature, show that a third copy of chromosome 21 disturbs the expression of all DNA in the genome. The surprise result may change understanding of Down syndromes symptoms, as well as other disorders caused by abnormal numbers of chromosomes, said Stylianos Antonarakis, a study author.

The results of this study complicate the understanding of molecular mechanisms of the symptoms of trisomy 21 and opens a new hypotheses for all chromosomal abnormalities, said Antonarakis, chairman of the Department of Genetic Medicine and Development at the University of Geneva Medical School in Switzerland, in an e-mail.

About 6,000 U.S. babies are born with Down syndrome each year. In addition to cognitive impairment, people with the condition may also suffer from ailments including heart defects, low muscle tone, vision and hearing problems and early onset Alzheimers disease. There is no cure.

The study compared a single set of identical twins in which just one twin had an extra chromosome 21. This unusual situation enabled researchers to study the effects of chromosome 21 without the bias of genome variability.

While gene expression has been studied extensively in Down syndrome, natural variations among individuals concealed the genome-wide effect of chromosome 21, researchers said.

The study found that gene dysregulation, or impairment, seen in the twin with Down syndrome is organized in domains or territories along all the different chromosomes.

Thus trisomy 21 could be now viewed as a general genomic disorder, and genes throughout the genome could be involved in the different signs and symptoms, Antonarakis said.

Humans normally have 46 chromosomes in each cell, divided into pairs. Chromosome 21 is the smallest human chromosome, accounting for less than 2 percent of the genome. Chromosome 21 probably contains 200 to 300 genes that provide instructions for making proteins.

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Down Syndrome Cause Revised by Study on Genome Effects

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Human Achievement – Video

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Human Achievement
Matt Ridley, author of The Rational Optimist, recounts the long, flawed history of pessimistic predictions and invites us to examine the facts behind our ine...

By: Dana Whitesides

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Human Achievement - Video

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UTD professor explains how the human brain changes with age

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Dr. Gagan Wig, an assistant professor at the University of Texas at Dallas Center for Vital Longevity, recently explained to members of its Directors Research Circle how the human brain networks. He talked about how it changes as people age and compared the human brain to social and tech networks and other systems with interacting parts.

Certain parts of the brain can also communicate like the way people in a neighborhood might interact with each other: Theyre friendly and talkative to some, while less social with others, he said.

Wigs lecture was part of the centers Directors Research Circle speaker series, which was founded by Dallas architect Bill Booziotis and the centers advisory council. The Directors Research Circle is made up of donors who commit to an annual gift of $2,500 or a minimum donation of $12,500 over five years.

Before joining the center, Wig earned a Ph.D. in cognitive neuroscience from Dartmouth College, completed a fellowship at Harvard University and joined the Human Connectome Project at Washington University School of Medicine, where he focused on understanding brain networks using neuroimaging.

His talk during an evening reception at Arlington Hall in Dallas Lee Park was attended by Ocie Kazee-McAllister, Rita Hortenstine, Katherine Frieberger, Don Daseke and Larry Warder, retired CFO at the U.S. Department of Education and current chair of the centers advisory council.

We are delighted to have Dr. Wig offer insight into new methods of understanding the brain that are having a huge impact in our field, said Dr. Michael Rugg, co-director of the center. Thanks to Dr. Wig and his colleagues at the center, were achieving new insights into the aging mind.

The next center event is a free public lecture next Wednesday at the Communities Foundation of Texas. Memory expert Dr. John Jonides of the University of Michigan will speak as the the first guest in the Jean and Bill Booziotis Distinguished Lecture Series, which was established in Jean and Bill Booziotis name. Reservations are required because seating is limited. Call Holly Hull Miori at 972-883-3728.

The Center for Vital Longevity was founded in 2010 by co-director Dr. Denise Park and has grown in the last four years to become one of the worlds leading centers on studying the aging mind. It is home to six research laboratories and a staff of more than 50.

For more information, contact Miori at 972-883-3728 or iori@utdallas.edu or visit cvlinfo.org.

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UTD professor explains how the human brain changes with age

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CRACK UND ULTRA ECZEMA Concert aux Romains 03 02 2012 – Video

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CRACK UND ULTRA ECZEMA Concert aux Romains 03 02 2012
8C prises de vues Nic Normal, Aline Battaglia, Aurlien Petit montage Homemade Mixture.

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CRACK UND ULTRA ECZEMA Concert aux Romains 03 02 2012 - Video