Washington, June 7 (ANI): A team of scientists has been able to predict the whole genetic code of a foetus by taking a blood sample from a woman who was 18 weeks pregnant, and a swab of saliva from the father.
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Category Archives: Genetic Medicine
Unborn babies could be tested for 3,500 genetic faults
By contrast, the scientists say their new test would identify far more conditions, caused by genetic errors.
However, they warned it raised many ethical questions because the results could be used as a basis for abortion.
These concerns were last night amplified by pro-life campaigners, who said widespread use of such a test would inevitably lead to more abortions.
The American scientists were able to map the babys genetic code principally from tiny traces free-floating DNA, which makes its way into the mothers blood.
Blood sample DNA from the mother was also studied as well as DNA extracted from the father's saliva.
Fitting pieces of the genetic jigsaw together, scientists in the US were able to reconstruct the entire genetic code of an unborn baby boy.
They were then able to see what spontaneous genetic mutations had arisen.
Such natural mutations - called de novo mutations - are responsible for the majority of genetic defects.
By checking their prediction of the babys genetic code with actual DNA taken after the birth, the team from the University of Washington in Seattle, found they were able to identify 39 of 44 such mutations in the child.
De novo mutations are thought to play a role in a number of complex conditions such as autism and schizophrenia.
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Study: Testing Unborn Babies for Genetic Disorders
Prospective parents might soon be able to screen their unborn babies for thousands of genetic disorders, according to a study published by Science Translations Medicine.
This is potentially a two-edged sword. Although it might pick up more curable conditions, some experts worry that it may lead to more abortions
American scientists were able to map the babys genetic code form tiny traces of free-floating DNA in blood from the babys mother, who was 18 weeks pregnant. They were also able to pinpoint if the mutations came from the mother or fathers side.
If the technique is refined and the technology becomes inexpensive, as many experts predict, this type of prenatal testing could allow doctors to screen unborn babies for 3,500 genetic disorders by taking a blood sample from the mother and a swab of saliva from the father.
Now, the only genetic disorder routinely testing is Down Syndrome.
On the positive side, picking up genetic problems early may lead to better treatments, sometimes while the baby is still a fetus, sometimes right after birth and that might prevent complications, said NBC4 health expert Dr. Bruce Hensel.
Some experts believe the finding is a double-edged sword, and could potentially raise ethical concerns.
It might give peace of mind if (parents) dont find problems. On the other hand, it could lead to dilemmas what do you do about them can you treat them, might it lead to more abortions? Hensel said.
The genetic predictions in the study were confirmed by analyzing umbilical cord blood collected at the babys birth.
The test is not being used yet, and experts said the methods will have to refined before the screenings are widely used.
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New Fetal Genome Sequencing Could Spot Disorders
In a development scientists are calling a "tour de force," researchers have reconstructed the genome of a fetus using DNA samples from the parents.
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Phentermine / Adipex Non RX PhenObestin 37.5 Offsets Obesity Risk Predicted by Genetic Scores
A recent study by researchers from Duke University that was published in Archive of Pediatrics and Adolescent Medicine identified and tracked specific genetic characteristics observable during childhood that led to a higher than average obesity risk during adulthood. The study identified Single-Nucleotide Polymorphisms (SNPs) that are associated with body mass indexes (BMIs) that are considered ...
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Phentermine / Adipex Non RX PhenObestin 37.5 Offsets Obesity Risk Predicted by Genetic Scores
New Drug Effective for Rare Genetic Skin Cancer: Studies
WEDNESDAY, June 6 (HealthDay News) -- When a clinical trial is stopped abruptly just eight months after its start, it's either very good or very bad news.
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New testing could help spot genetic disorders
In a development scientists are calling a "tour de force," researchers have reconstructed the genome of a fetus using DNA samples from the parents.
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Because their technique did not require an invasive test to take samples from the fetus itself, it's an important step toward what could become a low-risk way to identify genetic disorders early in development, experts say.
Currently, "when genetic testing is done, it's done for just a few diseases," said lead author Dr. Jay Shendure, an associate professor of genome sciences at the University of Washington.
A test based on the new technique could detect the roughly 3,000 conditions known as Mendelian disorders, each of which are the result of a single mutated gene, Shendure said. Huntington's disease, hemophilia and sickle-cell anemia fall into this category.
While each of these disorders is relatively rare, together they affect about 1 percent of births, Shendure said.
"This is amazing," said Dr. Ada Hamosh, director of the Institute of Genetic Medicine at the Johns Hopkins University School of Medicine, of the findings. "On the other hand, in no way is this ready for prime time," said Hamosh, who was not involved with the research.
Shendure and colleagues put together the fetal genome using a saliva sample from the father, and a sample of blood plasma from the mother. About 13 percent of the DNA found outside of cells in a pregnant woman's body belongs to her fetus.
They sequenced the regions of DNA they were aiming for with 98.2 percent accuracy.
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Blood Test May Spot Genetic Disease in Fetuses
New Test Uses Mom's Blood, Dad's Saliva to Determine Baby's Genetic Code
June 6, 2012 -- Samples of blood and saliva from parents-to-be may help identify thousands of genetic disorders in fetuses soon after conception without invasive testing, researchers say.
In a study published today in the journal Science Translational Medicine, researchers from the University of Washington report that they were able to determine the complete DNA sequence of two babies in the womb by analyzing blood samples from the mother and saliva samples from the father.
Genetic predictions were confirmed once the babies were born by analyzing umbilical cord blood collected at birth.
The test is not ready for use yet. Although cost and technological challenges remain, the research could lead to a simple non-invasive test to identify more than 3,000 disorders caused by single-gene mutations, says study co-author Jay Shendure, MD, PhD.
"Many of these diseases are so rare that most people have never heard of them, but collectively they affect around 1% of births," Shendure tells WebMD.
Only a few genetic disorders, including Down syndrome, are screened for during pregnancy. They use invasive and potentially risky procedures such as amniocentesis and chorionic villus sampling.
The search is underway for less invasive tests using blood samples from pregnant women instead of fluid from the uterus. That's based on the recognition that fetal DNA is present in the blood of pregnant women at varying concentrations during pregnancy.
In the newly published study, researchers confirmed that blood taken from an expectant mother about 18 weeks into her pregnancy and saliva specimens taken from the father contained enough genetic information to map the DNA code of the developing fetus.
The finding was later confirmed in another expectant couple with blood taken from the mother even earlier in her pregnancy.
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Doctors try to make sense of cancer's genetic jumble
CHICAGO (Reuters) - Not too long ago, knowing the organ where a cancer first takes hold was generally all a doctor needed to determine what treatments to use. Not anymore. Advances in understanding cancer at the molecular level mean doctors can better select the drugs that will most help individual patients. To do so, they must identify which genetic mutations are driving the growth of a patient ...
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Genetic Risk Scores And Obesity Later In Life Among Children
Editor's Choice Academic Journal Main Category: Genetics Also Included In: Pediatrics / Children's Health;Obesity / Weight Loss / Fitness Article Date: 05 Jun 2012 - 14:00 PDT
Current ratings for: 'Genetic Risk Scores And Obesity Later In Life Among Children'
The researchers explain that obesity can be inherited and GWASs (genome-wide association studies) have started to reveal the molecular roots of heritability by identifying SNPs (single-nucleotide polymorphisms) which are associated with higher BMIs (body mass indexes).
Daniel W. Belsky, Ph.D., and team wrote:
The researchers gathered data on 1,037 New Zealanders who were members of the Dunedin Multidisciplinary Health and Development Study. 52% of them were males. They were all born between April 1972 and March 1973. They were assessed every few years up to the age of 38 years.
Participants with higher GRSs (genetic risk scores) had greater BMIs between ages 3 to 38 for every age assessed. Children identified with a high genetic risk were found to have a 1.61 to 2.41 times higher chance of becoming obese during their teens to late thirties , and 1.90 times more likely to become chronically obese across over three assessments compared to the other kids.
Children at higher genetic risk experienced more severe adiposity rebound than other kids. Adiposity rebound means gaining fat after losing weight - piling the pounds back on. Adiposity rebound also appeared to occur earlier on among kids at higher genetic risk.
Children of normal weight at higher genetic risk, whose parents were overweight, were found to have faster growth and a greater chance of becoming obese.
The authors explained that genetic score risk contributed "independent and additive information" to predicting how much children might grow and/or become obese later on in life - this data went beyond family history data.
In the same journal, the authors concluded:
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Genetic Risk Scores And Obesity Later In Life Among Children
Pathway Genomics Selected as a “Cool Company” by San Diego Venture Group
SAN DIEGO--(BUSINESS WIRE)--
Pathway Genomics Corporation, a clinical genetic testing laboratory and results interpretation service based in San Diego, has been selected by San Diego Venture Group as one of 30 cool companies to be featured at its 10th Annual Venture Summit on June 6. Selected from a field of over 150 applicants, Pathway Genomics and the other 29 companies will be a prominent part of the event, which draws more than 100 venture capitalists and 500 attendees.
The selection is a reminder that companies like Pathway are at the forefront of a major shift in the way medicine is practiced throughout the world, said Jim Plante, Pathways founder and CEO.
Pathway provides genetic tests for drug responses, nutrition and exercise response, inherited genetic conditions, and risk of many diseases. Pathway consists of more than 40 scientific and medical professionals, including medical doctors, molecular geneticists, and genetic counselors, as well as a world-leading scientific advisory board.
To learn more about Pathways genetic testing services, visit http://www.pathway.com. For more information about San Diego Venture Groups Cool Companies 2012 and its 10th Annual Venture Summit, visit http://www.sdvg.org/venturesummit.
About Pathway Genomics
Pathway Genomics owns and operates an on-site genetic testing laboratory that is accredited by the College of American Pathologists (CAP), accredited in accordance with the U.S. Health and Human Services Clinical Laboratory Improvement Amendments (CLIA) of 1988, and licensed by the state of California. Using only a saliva sample, the company incorporates customized and scientifically validated technologies to generate personalized reports, which address a variety of medical issues, including an individuals carrier status for recessive genetic conditions, food metabolism and exercise response, prescription drug response, and propensity to develop certain diseases such as heart disease, type 2 diabetes and cancer. For more information about Pathway Genomics, visit http://www.pathway.com.
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Pathway Genomics Selected as a “Cool Company” by San Diego Venture Group
Genetics, rapid childhood growth and the development of obesity
Public release date: 4-Jun-2012 [ | E-mail | Share ]
Contact: Mary Jane Gore mary.gore@duke.edu 919-660-1309 JAMA and Archives Journals
CHICAGO A 38-year longitudinal study of New Zealanders suggests that individuals with higher genetic risk scores were more likely to be chronically obese in adulthood, according to a report published in the June issue of Archives of Pediatrics & Adolescent Medicine, a JAMA Network publication.
Obesity is capable of being inherited and genome-wide association studies (GWASs) have started to uncover the molecular roots of heritability by identifying multiple single-nucleotide polymorphisms (SNPs) associated with higher adult body mass index (BMI), the authors write in their study background.
"In this study, we asked how SNPs with replicated GWAS evidence for association with adult BMI relate to growth across the first four decades of life and to adult obesity in a birth cohort followed up prospectively from birth through 38 years of age," Daniel W. Belsky, Ph.D., of Duke University, Durham, N.C., and colleagues write in the study background.
Study participants were members of the Dunedin Multidisciplinary Health and Development Study, an investigation of health and behavior in a complete birth cohort. The 1,037 study members (52 percent were male) were born between April 1972 and March 1973 in Dunedin, New Zealand. Assessments were performed every few years starting at birth until 38 years.
Children with higher genetic risk scores (GRSs) had higher BMIs at every age assessed from age 3 through 38 years. Children at high genetic risk were 1.61 to 2.41 times more likely to be obese in their second, third and fourth decades of life and were 1.90 times more likely to be chronically obese across more than three assessments compared with children at low genetic risk, according to study results.
Adiposity rebound, when children begin to gain body fat after losing it during early childhood, occurred earlier in development and at higher BMI for children at higher genetic risk, the results indicate.
Higher genetic risk also predicted faster growth and increased obesity risk in children with normal-weight and overweight parents, the study results note. The authors comment that the GRS contributed "independent and additive information" to the prediction of children's growth and their risk for obesity in adulthood beyond the family history information.
"Thus, the results present compelling evidence that SNPs identified in GWASs of adult BMI and other obesity-related phenotypes predispose to more rapid growth in childhood, leading to increased risk for obesity in adulthood, and provide information not forthcoming from a simple analysis of family history," the authors conclude.
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Genetics, rapid childhood growth and the development of obesity
First Bedside Genetic Test Could Prevent Heart Complications
First Bedside Genetic Test Could Prevent Heart Complications
A genotyping test from a Canadian biotech company enables timely personalized drug treatment.
For some cardiac patients, recovery from a common heart procedure can be complicated by a single gene responsible for drug processing. The risk could be lowered with the first bedside genetic test of its kind. The test shows promise for quickly and easily identifying patients who need a different medication.
Quick test: This shoebox-sized device from Spartan Bioscience supports the first bedside genetic test. Spartan Bioscience
After a patient receives a heart stenta small scaffold that props open an arteryhis or her doctor will prescribe a blood thinner to prevent platelets from building up inside the device. However, for some 70 percent of patients with Asian ancestry and 30 percent of patients with African or European ancestry, a single genetic variant will prevent one of the most commonly prescribed blood thinners from working. Alternatives exist, but they are more expensive, so hospitals could use an easy way to identify who does and does not need the more expensive drug.
Canada's Spartan Biosciencehas developed a near "plug-and-play" genotyping device that allows nurses and others to quickly screen patients at the bedside, perhaps while they are undergoing the stent placement procedure. Users take a DNA sample from a patient's cheek with a specialized swab, add the sample to a disposable tube, and then place the tube and sample in a proprietary shoebox-sized machine and hit a button. Shortly thereafter, the user receives a printout of the patient's genetic status for the drug-processing variant. The whole procedure takes about an hour. Most clinicians currently have to wait several days for similar information to come from off-site genetics testing companies.
"For six years we've been plugging away at this, and we finally broke through about a year and a half ago," says Spartan Bioscience founder Paul Lem. He says the simple test came to life with innovations at every stepfrom the special swab that collects the right amount of DNA, to the chemicals in the disposable reaction tube, to the software that automates the DNA readingand a team with diverse backgrounds including his in medicine and molecular biology and others' in optical hardware.
Lem has kept an eye on other companies trying to create a bedside genetic test, some going after the same variant, and calculates that over $1 billion in capital has been spent over the last five years in this area.
The University of Ottawa Heart Institute researchers conducted a proof-of-principle trial for the device and found that the bedside test is effective at quickly identifying carriers of the drug-processing variant and can be performed by nurses with minimal training. The findings were published in The Lancet last week.
"The stakes are pretty high" for the risks associated with the variant in the test, says Euan Ashley, a cardiologist with Stanford's Center for Inherited Cardiovascular Disease. Patients who receive a stent implant after a heart attack or as a preventive measure are at risk for serious adverse events if their bodies cannot process a commonly prescribed anti-platelet drug into its active form. "There's a startling number of people who carry the variant, which leaves them at risk," says Ashley. "Being able to get an answer within an hour or twowhen you are thinking of a patient's heartis a pretty compelling case for [testing for it]."
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First Bedside Genetic Test Could Prevent Heart Complications
Some Genes Seem to Raise Risk of Obesity: Study
MONDAY, June 4 (HealthDay News) -- Some people's genetic makeup puts them at a higher risk for obesity, a new study says.
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Foundation Medicine: Personalizing Cancer Drugs
It's personal now: Alexis Borisy (left) and Michael Pellini lead an effort to make DNA data available to help cancer patients. Credit: Christopher Harting
Michael Pellini fires up his computer and opens a report on a patient with a tumor of the salivary gland. The patient had surgery, but the cancer recurred. That's when a biopsy was sent to Foundation Medicine, the company that Pellini runs, for a detailed DNA study. Foundation deciphered some 200 genes with a known link to cancer and found what he calls "actionable" mutations in three of them. That is, each genetic defect is the target of anticancer drugs undergoing testingthough not for salivary tumors. Should the patient take one of them? "Without the DNA, no one would have thought to try these drugs," says Pellini.
Starting this spring, for about $5,000, any oncologist will be able to ship a sliver of tumor in a bar-coded package to Foundation's lab. Foundation will extract the DNA, sequence scores of cancer genes, and prepare a report to steer doctors and patients toward drugs, most still in early testing, that are known to target the cellular defects caused by the DNA errors the analysis turns up. Pellini says that about 70 percent of cases studied to date have yielded information that a doctor could act onwhether by prescribing a particular drug, stopping treatment with another, or enrolling the patient in a clinical trial.
The idea of personalized medicine tailored to an individual's genes isn't new. In fact, several of the key figures behind Foundation have been pursuing the idea for over a decade, with mixed success. "There is still a lot to prove," agrees Pellini, who says that Foundation is working with several medical centers to expand the evidence that DNA information can broadly guide cancer treatment.
Foundation's business model hinges on the convergence of three recent developments: a steep drop in the cost of decoding DNA, much new data about the genetics of cancer, and a growing effort by pharmaceutical companies to develop drugs that combat the specific DNA defects that prompt cells to become cancerous. Last year, two of the 10 cancer drugs approved by the U.S. Food and Drug Administration came with a companion DNA test (previously, only one drug had required such a test). So, for instance, doctors who want to prescribe Zelboraf, Roche's treatment for advanced skin cancer, first test the patient for the BRAFV 600E mutation, which is found in about half of all cases.
About a third of the 900 cancer drugs currently in clinical trials could eventually come to market with a DNA or other molecular test attached, according to drug benefits manager Medco. Foundation thinks it makes sense to look at all relevant genes at oncewhat it calls a "pan-cancer" test. By accurately decoding cancer genes, Foundation says, it uncovers not only the most commonly seen mutations but also rare ones that might give doctors additional clues. "You can see how it will get very expensive, if not impossible, to test for each individual marker separately," Foundation Medicine's COO, Kevin Krenitsky, says. A more complete study "switches on all the lights in the room."
So far, most of Foundation's business is coming from five drug companies seeking genetic explanations for why their cancer drugs work spectacularly in some patients but not at all in others. The industry has recognized that drugs targeted to subsets of patients cost less to develop, can get FDA approval faster, and can be sold for higher prices than traditional medications. "Our portfolio is full of targets where we're developing tests based on the biology of disease," says Nicholas Dracopoli, vice president for oncology biomarkers at Janssen R&D, which is among the companies that send samples to Foundation. "If a pathway isn't activated, you get no clinical benefit by inhibiting it. We have to know which pathway is driving the dissemination of the disease."
Cancer is the most important testing ground for the idea of targeted drugs. Worldwide spending on cancer drugs is expected to reach $80 billion this yearmore than is spent on any other type of medicine. But "the average cancer drug only works about 25 percent of the time," says Randy Scott, executive chairman of the molecular diagnostics company Genomic Health, which sells a test that examines 16 breast-cancer genes. "That means as a society we're spending $60 billion on drugs that don't work."
Analyzing tumor DNA is also important because research over the past decade or so has demonstrated that different types of tumors can have genetic features in common, making them treatable with the same drugs. Consider Herceptin, the first cancer drug approved for use with a DNA test to determine who should receive it (there is also a protein-based test). The FDA cleared it in 1998 to target breast cancers that overexpress the HER2 gene, a change that drives the cancer cells to multiply. The same mutation has been found in gastric, ovarian, and other cancersand indeed, in 2010 the drug was approved to treat gastric cancer. "We've always seen breast cancer as breast cancer. What if a breast cancer is actually like a gastric cancer and they both have the same genetic changes?" asks Jennifer Obel, an oncologist in Chicago who has used the Foundation test.
The science underlying Foundation Medicine had its roots in a 2007 paper published by Levi Garraway and Matthew Meyerson, cancer researchers at the Broad Institute, in Cambridge, Massachusetts. They came up with a speedy way to find 238 DNA mutations then known to make cells cancerous. At the time, DNA sequencing was still too expensive for a consumer testbut, Garraway says, "we realized it would be possible to generate a high-yield set of information for a reasonable cost." He and Meyerson began talking with Broad director Eric Lander about how to get that information into the hands of oncologists.
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Marfan Syndrome [Marfan Syndrome] – Video
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New genetic factor associated with lean diabetics identified
Washington, June 2 : Lean type 2 diabetes patients have a larger genetic disposition to the disease as compared to their obese counterparts, a new study has proved.
Type 2 diabetes is popularly associated with obesity and a sedentary lifestyle. However, just as there are obese people without type 2 diabetes, there are lean people with the disease.
It has long been hypothesised that type 2 diabetes in lean people is more "genetically driven".
The study, from a research team led by the Peninsula College of Medicine and Dentistry (PCMD), University of Exeter, has also identified a new genetic factor associated only with lean diabetes sufferers.
Using genetic data from genome-wide association studies, the research team tested genetic markers across the genome in approximately 5,000 lean patients with type 2 diabetes, 13,000 obese patients with the disease and 75,000 healthy controls.
The team found differences in genetic enrichment between lean and obese cases, which support the hypothesis that lean diabetes sufferers have a greater genetic predisposition to the disease.
This is in contrast to obese patients with type 2 diabetes, where factors other than type 2 diabetes genes are more likely to be responsible. In addition, genetic variants near the gene, LAMA1, were linked to type 2 diabetes risk for the first time, with an effect that appeared only in the lean patients.
"Whenever a new disease gene is found, there is always the potential for it to be used as a drug target for new therapies or as a biomarker, but more work is needed to see whether or not this new gene has that potential," John Perry, one of the lead authors of the study, said.
"This is the first time that a type 2 diabetes gene has been found to act in this way - we do not know why it should be associated in one sub-group of patients and not another.
"It could point to the fact that type 2 diabetes may not be one disease, but may represent a number of subgroups. Again, more work is required to prove this hypothesis.
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New genetic factor associated with lean diabetics identified
New finding 'may lead to genetic test that predicts heart failure beforehand'
Washington, June 2 (ANI): The serendipitous chain of events that took place in a new study could lead to a genetic test that can help predict heart failure in certain people before it happens.
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New finding 'may lead to genetic test that predicts heart failure beforehand'
'Jack Spratt' diabetes gene identified
Public release date: 1-Jun-2012 [ | E-mail | Share ]
Contact: Andrew Gould andrew.gould@pcmd.ac.uk 44-018-843-8346 University of Exeter
Type 2 diabetes is popularly associated with obesity and a sedentary lifestyle. However, just as there are obese people without type 2 diabetes, there are lean people with the disease.
It has long been hypothesised that type 2 diabetes in lean people is more 'genetically driven'. A new study from a research team led by the Peninsula College of Medicine and Dentistry (PCMD), University of Exeter, which involved research institutions from around the world, has for the first time proved that lean type 2 diabetes patients have a larger genetic disposition to the disease than their obese counterparts. The study has also identified a new genetic factor associated only with lean diabetes sufferers.
The study is published in PLoS Genetics.
Using genetic data from genome-wide association studies, the research team tested genetic markers across the genome in approximately 5,000 lean patients with type 2 diabetes, 13,000 obese patients with the disease and 75,000 healthy controls.
The team found differences in genetic enrichment between lean and obese cases, which support the hypothesis that lean diabetes sufferers have a greater genetic predisposition to the disease. This is in contrast to obese patients with type 2 diabetes, where factors other than type 2 diabetes genes are more likely to be responsible. In addition, genetic variants near the gene, LAMA1, were linked to type 2 diabetes risk for the first time, with an effect that appeared only in the lean patients.
Dr. John Perry, one of the lead authors of the study, said: "Whenever a new disease gene is found, there is always the potential for it to be used as a drug target for new therapies or as a biomarker, but more work is needed to see whether or not this new gene has that potential."
He added: "This is the first time that a type 2 diabetes gene has been found to act in this way we do not know why it should be associated in one sub-group of patients and not another. It could point to the fact that type 2 diabetes may not be one disease, but may represent a number of subgroups. Again, more work is required to prove this hypothesis."
Dr. Perry concluded: "This study is a truly international one, bringing together research teams from around the world and leading UK institutions such as the University of Oxford, the University of Cambridge, King's College London, the University of Dundee and the University of Edinburgh."
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Mutant flies confirm genetic link to restless legs syndrome | Not Exactly Rocket Science
In a lab in Atlanta, a group of flies is sleeping fitfully. Their naps are fragmented, and their legs are twitching. Their behaviour is uncannily similar to people who have a condition called restless leg syndrome (RLS). When such people are awake, they experience uncomfortable sensations in their limbs that compel them to move to get some relief. Their sleep, which is fragmented and disturbed, is characterised by the same involuntary movements.
Theres a good reason for these similarities. Amanda Freeman from the Emory University School of Medicine has engineered the flies so that they have a faulty copy of BTBD9, a gene that has been linked to RLS in humans. The fact that they show the same constellation of symptoms strongly suggests that this gene is genuinely involved in the condition.
In 2007, two teams of scientists linked BTBD9 to the repeated limb movements that occur during RLS. A single change in the genes sequence increased the risk of such movements by more than 50 per cent, and was probably involved in around half of such cases. One of the teams wrote that the discovery provides evidence that periodic limb movements in sleep is a genuine syndrome with a detectable genetic basis. Thats important, especially since critics have suggested that many RLS cases are the product of disease-mongering by the pharmaceutical industry in order to sell more drugs.
But showing a correlation between a gene and a symptom is just the first step. You also need to work out what the gene is doing and that was unclear. The gene was switched on throughout the brain, but no one really knew what it did. Freeman has gone some way to solving that mystery, and cementing BTBD9s connection with RLS, by studying fruit flies.
Flies also have a version of BTBD9, which is also switched on throughout the nervous system. When Freeman mutated the gene so it could no longer be used, it affected how the flies slept. (Like use, flies stay still for distinct periods throughout the day, when they become unresponsive to the outside world; if theyre deprived of such bouts, they need more rest later.) Those with inactive copies of BTBD9 slept for the same amount of time as normal flies, but in fragmented bouts.
They also walked more during their sleep, moving their limbs in a way that mirrored the restlessness of people with RLS. In the video above, the flies in the blue lanes are normal, while those in the red lanes are the mutants. Note how much more active they are.
This suggests that the original human studies were pointing in the right direction, says Subhabrata Sanyal, who led the new research. However, he cautions that it is too early to say whether this gene does exactly the same things in flies and humans. The symptoms look superficially similar, but theyre not an exact match. People with RLS also rhythmically flex their feet, something that Sanyal says is virtually impossible to see in flies.
On top of that, we still understand very little about RLS as a human condition. Its diagnosis involves a questionnaire rather than a clinical test, and its still unclear if it is one syndrome with a consistent set of symptoms, or many. It is conceivable that not all RLS patients have the same disorder, says Sanyal.
This is another area where basic science could help. In humans, RLS has been linked to a lack of dopamine (a signalling chemical in the brain), and a deficiency of iron. Freeman found evidence to support both ideas. Her mutant flies had around half as much dopamine in their brains as normal ones, and they slept more soundly once she gave them a dopamine-boosting drug. In human cells, she also found that BTBD9 controls the levels of ferritin, a protein that stores and releases iron.
Its a start, and Sanyal emphasises that its a tiny step. He also wants to study the role of the gene in rodents, and he suspects that it is involved in a process called ubiquitination, where small chemicals are attached to proteins to control where they are sent and when they are destroyed. Studying [BTBD9] in much greater detail is necessary to understand exactly what it does in neurons, he says.
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Mutant flies confirm genetic link to restless legs syndrome | Not Exactly Rocket Science