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Genome
study solves the mystery of twin’s illness
This Universe Trends |
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Genome study solves the mystery of twin’s illness When
Noah and Alexis Beery were diagnosed with cerebral palsy nearly 13 years ago, the diagnosis never sat right with the twins’ mother, Retta Beery. Her lengthy search for the true cause of her children’s strange collection of symptoms finally led to an answer when a scan of the twins’ genomes turned up a genetic defect that caused the children’s disorder and finally led to the right treatment. The investigation offers a rare glimpse at the potential of whole genome sequencing-now largely reserved for research- at improving the treatment of individual disease. Now, the once-disabling disorder that caused involuntary spasms and left one twin unable to walk is all but gone, and both teens are thriving in school and playing sports. “If you saw them today, you’d say there was nothing wrong with them,” said Dr. Matthew Bainbridge of Baylor Genome Sequencing Center in Texas, whose research appears in the journal Science Translational Medicine. Whole genome sequencing technology allows researchers to read all the little bits of code-the A, C, T, G sequences- that are the building blocks of DNA. At a cost of $10,000 to $20,000 per patient, the technology is still out of reach for most people, but companies such as Illumina, Life Technologies Corp and Roche Holding are working to bring the cost down. Beery’s relentless search previously led the children to Dr. John Fink of the University of Michigan, who diagnosed the children, then age 5, with dopa-responsive dystonia (DRD), a complex movement disorder involving the loss of the neurotransmitter dopamine. The muscles of people with dystonia contract and spasm involuntarily. When the twins were given a drug called L-dopa, which substituted for the neurotransmitter dopamine that they lacked, they responded quickly. But there were still some lingering symptoms, and six years ago, Alexis developed a cough that became increasingly debilitating. “About a year and a half ago it turned from this horrible cough into this massive breathing problem. We were back in the arena of specialists, trying to figure out what was going on,” Beery said in a telephone interview. As luck would have it, the twins’ father had recently taken a job as chief information officer for the Life Technologies, maker of gene sequencing machines. With his wife’s prodding, the couple approached the company and asked if their children could have their genomes sequenced through a joint project with Baylor. “They approached us and asked if we would be willing to do it. We didn’t know how it would turn it,” Bainbridge said. When the researchers analyzed raw DNA sequence data from the twins’ genomes, they were surprised to find no mutations in the two genes commonly mutated in DRD. Instead, the team discovered that the twins carried a mutated gene related to serotonin production that made them deficient in both dopamine and serotonin, another neurotransmitter. Adding a serotonin-inducing supplement called 5-HTP to their dopamine regimen improved their symptoms dramatically after just a few weeks. “Now, because of the sequencing, Alexis started on this new amino acid and she started back in track in March,” Retta Beery said. “She’s been winning races.” While the cost of sequencing puts this technology out of reach for most families, Bainbridge thinks it will soon be affordable as sequencing costs continue to fall. He said currently the price of sequencing is dropping by half every six months. “It’s our hope that in two years or maybe even a year whole genome sequencing will be more widely available,” he said. “We’d like everyone to be able to have this.”
— Reuters
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This Universe When
we are on a mountain we are nearer the sun, but it is cold rather than hot. Why does the same happen when we are flying? Most hill stations are about 2 km above sea level - that is about the altitude of Shimla, or Ooty. Distance of the Sun from the earth is 250 million km. Surely, this much change in distance cannot make any difference. In any case when we go up a mountain we are not moving towards the sun at all times of the day. The reason for the lower temperature at high altitude is very different. You must have noticed and heard that as you go up the air becomes thinner. The pressure of the atmosphere decreases. The pressure is due to the mass of the air above. At sea level this is about 1000 grams on every centimetre square. This pressure is reduced as we go higher because there is less of air on top. Around the height of Shimla or Ooty it is reduced to about 800 grams. That is reduction by one fourth. When the pressure is reduced the molecules of air move further apart. For doing so they have to work against the attraction between them. Therefore they lose energy and the air becomes cooler. This is true for most gases. You can do simple experiments to prove it to yourself. You must have noticed that when you blow out air from your mouth, fast and with your lips compressed, the air feels cold on your hand. If, on the other hand, you breath out slowly with your mouth open the air feels warm. In the first case the compressed air is expanded while in the second case it comes out at same pressure and temperature it is inside your lungs. If your friend or your father does not spank you afterwards you can try another experiment. Just press the valve pin in the nozzle of a car or motorcycle tire and feel the temperature of the air coming out. You will find that it would be cool, if not cold. The only way we can have a stable atmosphere is to have the air get colder as we go high. This is the basic reason for it being colder on the hills. The air is thinner. There are other considerations that alter things a bit but we will let them be at the moment. Readers wanting to ask Prof Yash Pal a question can e-mail him at palyash.pal@gmail.com
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Trends CAPE CANAVERAL, Florida: Workers at the Kennedy Space Center filled the fuel tank of the space shuttle Atlantis on Wednesday in a key test ahead of its scheduled launch next month on the final shuttle flight. The test was added after structural problems were found last year on a tank later used for the February launch of sister ship Discovery. NASA reinforced metal supports inside both tanks. Scientists see sunspot “hibernation” but no Ice Age WASHINGTON: Sunspot cycles-those 11-year patterns when dark dots appear on the solar surface-may be delayed or even go into “hibernation” for a while, a U.S. scientist said on Wednesday. But contrary to some media reports, this does not mean a new Ice Age is coming, Frank Hill of the National Solar Observatory said in a telephone interview.
Iran puts satellite into orbit TEHRAN: Iran has successfully launched a second domestically built satellite into orbit, Iran’s Arabic language al-Alam television reported on Wednesday. The United States and its allies fear Iran is seeking to build nuclear bombs and are concerned that the long-range ballistic technology used to put satellites into orbit can also be used to launch warheads.
Protein linked with rare disease plays role in aging CHICAGO:
The same mechanism that causes children with a rare genetic disease called progeria to age at seven times the normal rate may play a role in normal aging as well, government researchers said. The study led by Dr. Francis Collins, director of the National Institutes of Health, suggests aging may not simply be a gradual wearing out of cells.
Auction features fighting dinosaur skeletons DALLAS: Natural history buffs with Tyrannosaurus-sized bank accounts got a chance to ante up on Sunday when an unusually large collection of fully assembled, museum-quality dinosaur skeletons was put up for auction. The featured stars of the Heritage Auctions bidding were a “fighting pair” of dinosaur skeletons that sold to a museum for $2.75 million, and an enormous, 19-foot-long triceratops that fetched $657,250 from a private collector.
— Reuters
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Doctors
use genome sweep to diagnose 
