Category Archives: Human Genetics

By inserting bits ofhuman DNAinto mice, scientists were able to make their brains develop more rapidly -- and ultimately grow bigger -- in the womb. The study, published Thursday in Current Biology, suggests that the evolution of thisgene may be one of the things that sets us apart from our close relatives in the primate world.

Human brains are unique, even when compared with our close genetic relatives, such as chimpanzees. Our brains are about three times heavier than those of our cousins, and are more complex and interconnected as well. It's generally accepted that these neurological differences are what allowed us to evolve the higher brain function that other primates lack. But just what genetic changes allowed humans to surpass chimps in the brain arena is one that's still being answered.

There are a lot of physical differences to examine more closely, but size is such a dramatic one that the authors of the new study chose to start there.

Using databases created by other labs, the Duke University scientists cross-checked areas of human DNA that had developed differences from chimp DNA with areas of DNA they expected to be important for gene regulation. Regulator genes help determine how other genes will express themselves, and the researchers suspected that some of these regulators might be making brain development more active in human embryos than in chimps.

They ended up focusing on a region called HARE5 (short for human-accelerated regulatory enhancer), which testing indicated had something to do with brain development. They suspected that the enhancer, which is found close to a molecular pathway important in brain development, might have changed in a way that influenced brain size in humans.

"We discovered that the human DNA sequence, which only had 16 changes in it compared to the chimp sequence, was being expressed differently in mice," said study authorDebra Silver, an assistant professor of molecular genetics and microbiology in the Duke University Medical School.

In fact, HARE5 was regulating how many neural stem cells -- the precursors of brain cells -- a mouse embryo could produce.

"The human DNA was really able to accelerate the way the stem cells divide," Silver said. "And as a result, the mice were able to produce more neurons."

The brains of these genetically modified mice grew 12 percent bigger than ones given the chimpanzee version of HARE5.

For humans, Silver said, this difference could be crucial. Humans and chimps have similar gestation periods, which are fairly long when compared with other species.

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Debra Silver comments: Scientists pinpoint a gene regulator that makes human brains bigger

Researchers are beginning to understand how DNA makes some athletes more likely to get hurt.

Injury is a fact of life for most athletes, but some professionalsand some weekend warriors, for that matterjust seem more injury-prone than others. But what is it about their bodies that makes the bones, tendons, and ligaments so much more likely to tear or strainbad luck, or just poor preparation?

A growing body of research suggests another answer: that genetic makeup may play an important role in injury risk.

A review article recently published in the Clinical Journal of Sports Medicine emphasizes that research on the genetics of sports injuries holds great potential for injury prevention for athletes at every level. The authors, from Stanford Universitys department of developmental biology and genetics, believe that genetic testing also gives athletes valuable information that might increase their competitive edge.

Stuart Kim, one of the studys authors and a professor of genetics at Stanford, says his interest in sports injuries began almost by accident. I initially intended to study the genes associated with the large size of NFL lineman, but the athletes werent really interested in finding out the genetic reasons why they were so big, Kim says. But they were extremely interested in figuring out what injuries they were more likely to sustain.

Genetic information can be valuable for amateur athletes, tooregardless of skill level, someone about to join a recreational basketball league or a tennis club would be well-served to know if theyre at risk of blowing out an ACL or tearing an Achilles. Each year, around 2 million adults go to the emergency room for sports-related injuries, many of them acquired during pickup games or matches in recreational leagues.

Within the field of sports-injury genetics, some studies have focused on variations in the genes that control the production of collagen, the main component of tendons and ligaments. Collagen proteins also form the backbone of tissues and bones, but in some people, structural differences in these proteins may leave the bodys structures weaker or unable to repair themselves properly after injury. In a study published in the British Journal of Sports Medicine in 2009, South African researchers found that specific variations of a collagen gene named COL1A1 were under-represented in a group of recreational athletes who had suffered traumatic ACL injuries. Those who had torn their ACL were four times as likely as the uninjured study subjects to have a blood relative who had suffered the same injury, suggesting that genetics are at least partially responsible for the strength of the ligament.

The same COL1A1 gene has also been linked to other soft-tissue injuries, like Achilles-tendon ruptures and shoulder dislocations. In a review article that combined the results of multiple studies on the COL1A1 gene, published in the British Journal of Sports Medicine in 2010, researchers concluded that those with the TT genotypeone of three potential variants of the gene, found only in 5 percent of the populationare extremely unlikely to suffer a traumatic ligament or tendon injury.

However, because of the vast complexity of the human genome, its highly improbable that a single variant within a gene can determine a persons genetic risk for a given soft-tissue injury. Researchers agree its much more likely that these injuries, like complex conditions such as obesity or type 2 diabetes, are influenced by multiple genes.

The COL5A1 gene, another one associated with collagen production, has been linked to a higher risk of injury of the ACL and Achilles tendon, as well as greater susceptibility to exercise-induced muscle cramping. A 2013 study in the Clinical Journal of Sports Medicine found that specific variants of COL5A1 were strongly correlated with muscle cramping among runners in the Two Oceans Marathon in South Africa.

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The Genetics of Being Injury-Prone

An Ebola vaccine candidate that has been undergoing human trials in the lab now will be used in trial on people in a real world environment with assistance from the Ames-based biopharmaceutical company NewLink Genetics Corporation.

On Thursday, the company announced that with its collaboration with pharmaceutical company Merck, a vaccine for the virus, which has reached epidemic status in parts of Africa and popped up in other parts of the world, will soon begin clinical trials in Liberia.

The control group will be comprised of 27,000 patients and there are plans to do trials in other countries.

We are cautiously optimistic that the trials will lead to data that says the vaccine works, said Charles Link, CEO of NewLink Genetics.

There is no timeline for results, and Link said the trials will take several months.

The company will also receive $20 million in connection with the achievement. The company received $30 million when it first reached a license agreement with Merk in 2014.

Merck obtained an exclusive license to research, develop, manufacture and distribute the Ebola vaccine candidate as well as any follow-on products

Other partners in this collaboration project include the government of Canada, the U.S. Department of Health and Human Services, the U.S. Department of Defense and the World Health Organization.

NewLink, which is located in the Iowa State University Research Park, began work with an Ebola vaccine in 2010 when it acquired the vaccine candidate from Public Health Agency of Canada, which developed it.

At that point, it was for animal experiments and not for humans, Link said. The laboratory work and research to get to the current point was accelerated because of the outbreak in West Africa.

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Ames company aids in Ebola vaccine candidate

Durham, NC - The size of the human brain expanded dramatically during the course of evolution, imparting us with unique capabilities to use abstract language and do complex math. But how did the human brain get larger than that of our closest living relative, the chimpanzee, if almost all of our genes are the same?

Duke scientists have shown that its possible to pick out key changes in the genetic code between chimpanzees and humans and then visualize their respective contributions to early brain development by using mouse embryos.

The team found that humans are equipped with tiny differences in a particular regulator of gene activity, dubbed HARE5, that when introduced into a mouse embryo, led to a 12% bigger brain than in the embryos treated with the HARE5 sequence from chimpanzees.

The findings, appearing online Feb. 19, 2015, in Current Biology, may lend insight into not only what makes the human brain special but also why people get some diseases, such as autism and Alzheimers disease, whereas chimpanzees dont. I think weve just scratched the surface, in terms of what we can gain from this sort of study, said Debra Silver, an assistant professor of molecular genetics and microbiology in the Duke University Medical School. There are some other really compelling candidates that we found that may also lead us to a better understanding of the uniqueness of the human brain.

Every genome contains many thousands of short bits of DNA called enhancers, whose role is to control the activity of genes. Some of these are unique to humans. Some are active in specific tissues. But none of the human-specific enhancers previously had been shown to influence brain anatomy directly.

In the new study, researchers mined databases of genomic data from humans and chimpanzees, to find enhancers expressed primarily in the brain tissue and early in development. They prioritized enhancers that differed markedly between the two species.

The groups initial screen turned up 106 candidates, six of them near genes that are believed to be involved in brain development. The group named these human-accelerated regulatory enhancers, HARE1 through HARE6.

The strongest candidate was HARE5 for its chromosomal location near a gene called Frizzled 8, which is part of a well-known molecular pathway implicated in brain development and disease. The group decided to focus on HARE5 and then showed that it was likely to be an enhancer for Frizzled8 because the two DNA sequences made physical contact in brain tissue.

The human HARE5 and the chimpanzee HARE5 sequences differ by only 16 letters in their genetic code. Yet, in mouse embryos the researchers found that the human enhancer was active earlier in development and more active in general than the chimpanzee enhancer.

Whats really exciting about this was that the activity differences were detected at a critical time in brain development: when neural progenitor cells are proliferating and expanding in number, just prior to producing neurons, Silver said.

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Evolving a Bigger Brain With Human DNA

3 Parent Babies Coming Soon : UK to Make Babies from DNA of Three People [Designer Babies: VIRAL]
LONDON Britain moved Tuesday toward allowing scientists to create humans from the DNA of three people. The technology aims to liberate future generations f...

By: SP TV

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3 Parent Babies Coming Soon : UK to Make Babies from DNA of Three People [Designer Babies: VIRAL] - Video

Code interacts with human genome to tell DNA what to do

(ANSA) - Rome, February 18 - The most comprehensive information so far into the human epigenome - chemical compounds that modify or mark human DNA to give it instructions about how to perform - was released to the public on Wednesday in a free online database and in 24 articles published by the Nature group of scientific magazines. The research is a product of the Roadmap Epigenomics Program, an 2008 initiative funded by the U.S. government at a cost of 240 million dollars, planned to last 10 years. This release of information about the human epigenome is being hailed as the most important discovery into human genetics since the 2001 publishing of the first draft of the human genome, the chemical sequences that make up DNA. Researchers hope epigenomic information will help cure and prevent diseases like diabetes, hypertension, arthritis and Alzheimer's by decoding how the epigenome operates on human DNA.

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Scientists unveil 'epigenome roadmap' genetic code

Bacteria found in pubic hair could be used to trace a persons involvement in sexual assault cases, according to a study published in Investigative Genetics.

Hairs are one of the most common types of trace evidence collected during forensic investigations, but the majority of those recovered from crime scenes contain insufficient amounts of human genetic material to carry out DNA profiling of suspects.

Not only did the study report that bacteria associated with pubic hair can distinguish between males, females and individual people, but it found that an individuals pubic hair microbiota are transferred during intercourse, indicating its potential for forensic analysis in sexual assault cases.

The transfer of bacteria between victim and offender, in rape cases, may provide a new way of linking the offender to the victim in instances in which no human DNA is transferred, said lead author Ms Silvana Tridico of Murdoch University.

The small study collected pubic and scalp hair from seven individuals, two of whom were a cohabiting couple. Scalp hair showed fewer distinct varieties of microbe and appeared to be more influenced by common environmental microbes. In contrast, each individuals pubic hair harboured distinct communities of microbe.

While the microbial communities on pubic hair generally remained individually distinct and consistent over the course of the study, after 5 months the cohabiting couples microbiota were more similar to each other than previously.

Interviews revealed that the couple had sexual intercourse 18 hours prior to the collection of their pubic hairs. This suggests that an exchange of microbes had occurred, which the researchers say bodes well for future forensic applications involving sexual crimes.

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Pubic Microbes Finger Sex Offenders

Pathophysiology Treatment of Medial Vascular Calcification
Jos Luis Milln, Ph.D. Professor, Human Genetics Program Sanford-Burnham Medical Research Institute Rare Disease Day Symposium 2012.

By: SanfordBurnham

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Pathophysiology & Treatment of Medial Vascular Calcification - Video

Jenny Taylor: Personalised Medicine
Dr Jenny Taylor is the Programme Director for the Genomic Medicine Theme at the Wellcome Trust Centre for Human Genetics. Her research aims to bridge the gap...

By: OxfordNDM - Nuffield Department of Medicine

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Jenny Taylor: Personalised Medicine - Video

TRENTON, N.J. (AP) Imagine being able to identify people likely to develop a particular disease and then stop it before it starts.

This isn't a science fiction tale. It's the ambitious goal of three research projects just launched by Johnson & Johnson's pharmaceutical research arm, Janssen Research & Development, that the company says are aimed at redefining health care.

The projects announced Thursday ultimately aim to prevent illnesses, particularly ones related to aging and lifestyle. That way, as people live longer, fewer of their "golden years" are plagued by poor health, disability and staggering medical bills.

"A hundred years from now, someone's going to look back on us and say, 'Can you believe they waited until you got a disease and then did something?'" Dr. William Hait, head of Janssen R&D, predicted in an exclusive interview with The Associated Press.

Instead, the world's biggest maker of health care products will try to find ways to prevent common, frightening and often deadly disorders, including Alzheimer's disease, cancer, heart disease, immune conditions and Type 1 diabetes, the first planned target. Janssen is partnering with the Juvenile Diabetes Research Foundation to find ways to prevent Type 1 diabetes, which is steadily becoming more prevalent.

Billions of research dollars will be needed to accomplish the goals, and it could easily take a generation, cautions analyst Steve Brozak, president of WBB Securities.

But Brozak said Johnson & Johnson is one of just a few organizations that have the resources money and scientific talent to succeed at what he called a shift to "true modern medicine" that's as revolutionary as Henry Ford creating the manufacturing assembly line.

"This is visionary stuff here," Brozak said. "Nobody's ever tried this."

Still, advances in the understanding of human genetics and diagnostic testing, and existing treatments that already help prevent widespread illnesses, have made Hait optimistic.

For example, blood testing and then use of cholesterol-lowering statin pills to prevent heart attacks and strokes in at-risk patients is widespread in developed countries. Ditto for colonoscopies and removal of any discovered polyps to prevent colon cancer, and Pap smears to spot cervical cell abnormalities that could turn into cancer.

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Johnson & Johnson projects aim to spot who'll get a disease