New Genetic Clues to Severe Childhood Epilepsy

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Exome sequencing technique may lead to discoveries about many diseases, researchers say

By Robert Preidt

HealthDay Reporter

SUNDAY, Aug. 11 (HealthDay News) -- A new technique used to identify genes associated with severe forms of childhood epilepsy could be used to find and confirm other gene mutations that cause neurological disorders, researchers report.

The scientists performed a technique called exome sequencing to search for non-inherited gene mutations associated with epilepsy in 264 children whose parents do not have epilepsy. They identified 25 such mutations in six genes: two new genes and four that had been previously linked with epilepsy.

The two forms of epilepsy associated with these gene mutations are called infantile spasms and Lennox-Gastaut syndrome, according to the study, which was funded by the U.S. National Institutes of Health and published Aug. 7 in the journal Nature.

Exomes represent all of a person's genes. Their DNA sequences provide the instructions for building all the proteins made by the body. The study authors said their findings suggest that exome sequencing may be a highly effective way to find and confirm many disease-causing gene mutations.

"It appears that the time for using this approach to understand complex neurological disorders has arrived," study co-leader David Goldstein, director of the Human Genome Variation Center at Duke University Medical Center, said in an NIH news release.

"This moderately sized study identified an unusually large number of disease-causing mutations and provides a wealth of new information for the epilepsy research community to explore," he said.

More than 2 million people in the United States have epilepsy, and infants and children are more likely to have epilepsy than adults. Some studies have identified genes associated with rare inherited forms of epilepsy, but finding genes associated with the majority of epilepsies has been difficult.

"Unlike some diseases, many of the genetic mutations associated with severe childhood epilepsies appear to be new mutations that are not inherited," Randall Stewart, a program director at the U.S. National Institute of Neurological Disorders and Stroke, said in the news release.

The researchers estimated that up to 90 genes could have epilepsy-causing mutations and that many of the mutations associated with epilepsy risk have previously been linked to other neurodevelopmental diseases, including autism.

"It appears that a few pathways may be responsible for many severe pediatric epilepsies," Goldstein said. "If true, then understanding epilepsies will be more manageable and we can find common pathways to target with drugs and other therapies."

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Genetic Overlap Seen in Five Mental Disorders

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Strongest link between schizophrenia and bipolar disorder, researchers say

By Robert Preidt

HealthDay Reporter

SUNDAY, Aug. 11 (HealthDay News) -- Five major mental disorders share common inherited genetic variations, a new study finds.

The overlap is highest between schizophrenia and bipolar disorder (15 percent), moderate between bipolar disorder and depression and between attention-deficit/hyperactivity disorder (ADHD) and depression (about 10 percent), and lowest between schizophrenia and autism (3 percent).

Overall, common genetic variations accounted for 17 percent to 28 percent of risk for the five mental disorders, according to the study published in the Aug. 11 issue of the journal Nature Genetics, which the researchers say is the largest genome-wide study of its kind.

The project involved more than 300 scientists at 80 research centers in 20 countries and was supported by the U.S. National Institute of Mental Health (NIMH).

The investigators analyzed the genomes of several thousand people with the five mental disorders and people without the disorders.

"Since our study only looked at common gene variants, the total genetic overlap between the disorders is likely higher," study co-leader Naomi Wray, of the University of Queensland in Australia, said in an NIMH news release. "Shared variants with smaller effects, rare variants, mutations, duplications, deletions, and gene-environment interactions also contribute to these illnesses."

The genetic overlap between schizophrenia and depression could prove important in terms of research and diagnosing patients, according to the study authors. They expected to see more overlap between ADHD and autism, but said the moderate overlap between schizophrenia and autism is consistent with emerging evidence.

"Such evidence quantifying shared genetic risk factors among traditional psychiatric diagnoses will help us move toward classification that will be more faithful to nature," said Bruce Cuthbert, director of the NIMH's adult translational research and treatment development division. Cuthbert is also the coordinator of an NIMH project that is working to develop a mental disorders classification system for research based more on underlying causes.

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Childhood Tummy Aches May Be Tied to Adult Anxiety, Depression

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Study looked at young adults a decade later

By Denise Mann

HealthDay Reporter

MONDAY, Aug. 12 (HealthDay News) -- Stomach pain is a common childhood complaint, and now a new study suggests it may place some kids at higher risk for anxiety disorders or depression as adults.

The researchers compared 332 young adults, aged around 20, who had abdominal pain as children to 147 participants who did not. Of those who had suffered from stomach pain, 51 percent had an anxiety disorder during their lifetime, and 30 percent had one currently. By contrast, only 20 percent of adults without stomach pain as children had an anxiety disorder.

"A decade later, individuals who had stomach pain continued to have high rates of anxiety disorders, even if they no longer had stomach pain," said study author Lynn Walker, a professor of pediatrics at Vanderbilt University in Nashville, Tenn.

Moreover, 40 percent of young men and women who had abdominal pain as children had depression during their lifetime, compared with 16 percent of adults who didn't have stomach pain, according to the study, which was published online Aug. 12 and in the September print issue of the journal Pediatrics.

Exactly how stomach pain and anxiety are linked is not entirely clear, but "anxiety related to the pain, or even anxiety related to other things in the child's life, can exacerbate the pain and lead to increased suffering and disability," Walker said.

To break the cycle early, parents of children who complain of stomach pain should first take their child to the doctor to see if anything is going on medically, she said.

"If no significant disease is found, parents should encourage their children to continue their regular activities even if they are having pain or anticipate that they might have pain," Walker said. "When children stay home from school and other activities, they get behind in schoolwork and peer relationships, which increases stress, which in turn increases their suffering."

It spirals from there. "As they discontinue activities and isolate themselves socially, they have more time to focus on the pain and worry about it," she said. "As they fall behind their peers, they have additional things to worry about."

In the study, social anxiety disorder -- a paralyzing fear of being judged by others -- occurred among a quarter of children with stomach pain.

Experts agreed that parents should seek help early for kids with recurrent stomach pain to try to reduce the risk of anxiety and depression.

"Parents should take an active role in their child's life by seeking both medical attention and supportive counseling for their child. This will prevent potential worsening of anxiety, and will help children learn better ways of coping with stressors that may exacerbate their pain," said Dr. Scott Krakower, a child and adolescent psychiatrist at Zucker Hillside Hospital in Glen Oaks, N.Y.

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Cigarette Taxes Deter Heavy Drinking, Study Suggests

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Smoking increases risk for problematic drinking, researcher notes

By Robert Preidt

HealthDay Reporter

FRIDAY, Aug. 9 (HealthDay News) -- Higher cigarette taxes help reduce drinking among certain groups of people, U.S. researchers say.

To assess the impact that increases in cigarette taxes between 2001-02 and 2004-05 had on drinking behavior, researchers analyzed data from more than 21,000 drinkers who took part in a survey from the National Institute on Alcohol Abuse and Alcoholism.

The cigarette tax increases were associated with modest to moderate reductions in drinking among "vulnerable groups," according to the study, which was published in the journal Alcoholism: Clinical & Experimental Research.

"Results suggest that increases in cigarette taxes were associated with reductions in alcohol consumption over time among male smokers," corresponding author Sherry McKee, an associate professor of psychiatry at Yale University School of Medicine, said in a journal news release. "The protective effects were most pronounced among subgroups who are most at risk for adverse alcohol-related consequences, including male heavy drinkers, young adults and those with the lowest income."

Smoking and heavy drinking occur together at very high rates, McKee said, noting that tobacco can enhance the subjective effects of alcohol and has been shown to increase the risk for heavy and problematic drinking.

Cigarette taxes, meanwhile, have been recognized as one of the most significant policy instruments to reduce smoking, McKee said. "By increasing the price of cigarettes, taxes are thought to encourage smokers to reduce their use of cigarettes or quit altogether, and discourage non-smokers from starting to smoke," she said.

Christopher Kahler, professor and chairman of the department of behavioral and social sciences at Brown School of Public Health, welcomed the new study. "These findings suggest that if states increase taxes on cigarettes, they are not only likely to reduce smoking -- based on a large body of literature -- but they also may have a modest impact on heavy drinking rates among men, those with lower income and those who drink most heavily," he said in the news release.

"In other words, policies that target one specific health behavior may have broader benefits to public health by affecting additional health behaviors that tend to co-occur with the targeted health behavior," he said.

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Asian Tiger Mosquito Could Spread U.S. Disease

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Present in more than half of states, the bloodthirsty parasite transmits a host of viruses

By Alan Mozes

HealthDay Reporter

FRIDAY, Aug. 9 (HealthDay News) -- What's striped black-and-white, packs a nasty bite and is a tireless spreader of disease? No, it's not a B-movie horror creature -- it's the Asian tiger mosquito.

And though a relative newcomer to the American scene, experts now warn that this intruder is starting to create a fearsome buzz, with the potential to cause havoc across the United States. So far, however, it hasn't led to widespread disease in this country.

"What we have here is an invasive daytime-feeding, disease-carrying mosquito that, since it first arrived on the East Coast in the 1980s, has been pretty aggressive in mowing down its natural competitors," said Gabe Hamer, a clinical assistant professor in the department of entomology at Texas A&M University. "And now it's really starting to move through the country in full force."

"That makes it, at the very least, a nuisance and an annoyance," Hamer explained. "And at worst, a serious vector for major pathogens."

On its Asian home turf, the mosquito is a well-known carrier of dengue fever, with West Nile fever, yellow fever, and encephalitis among the other debilitating illnesses for which it has been pegged as a transmitter.

According to the U.S. Centers for Disease Control and Prevention, the mosquito has so far been identified as a host for five different viruses in the United States. Two of those -- encephalomyelitis and Cache Valley -- can infect humans, while the others are a threat to dogs, cats, birds and other animals.

But U.S. experts are perhaps most alarmed that this mosquito potentially could become a prime North American vector for a particularly nasty joint and muscle pain illness for which there is neither a vaccine nor treatment: the Chikungunya virus.

Such concerns have escalated in light of recent research, such as that funded by the U.S. National Institute for Food and Agriculture, and reported in the January issue of PLoS Neglected Tropical Diseases, which cautions that an imminent mosquito-driven American outbreak of the Chikungunya virus is a very real threat.

"The ongoing invasion of the Asian tiger mosquito in the U.S.A. represents an important risk," agreed Diego Ruiz-Moreno, a postdoctoral associate in the department of ecology and evolutionary biology at Cornell University, who led the recent study. "Mainly because of the potential for disease to spread."

Otherwise known as Aedes albopictus, the CDC notes that the Asian tiger mosquito was first spotted on the U.S. mainland in 1985. Since that initial Houston sighting, it has spread across 26 states, moving as far north as Chicago, as far east as Pennsylvania and New Jersey, as far west as Nebraska, and across a broad swath of the South, including Florida, Georgia, South Carolina and Tennessee.

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Childhood Abuse Linked to Later Thyroid Problems for Women

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Stress hormone in 'fight-or-flight' reaction may be involved, researcher suggests

By Robert Preidt

HealthDay Reporter

FRIDAY, Aug. 2 (HealthDay News) -- Women who suffered physical abuse during childhood are at increased risk for thyroid problems, according to a new study.

"We found a significant association with thyroid disorders for women who were abused during childhood," lead author Esme Fuller Thomson, professor and chair at the University of Toronto's Faculty of Social Work, said in a university news release.

"We originally thought the link would be explained by factors such as daily stress, smoking or alcohol abuse -- characteristics associated with both childhood physical abuse and thyroid disorders -- but even after adjusting for 14 potential explanatory factors, women who had been physically abused in childhood had 40 percent higher odds of thyroid disorders than their non-abused peers," Fuller Thomson said.

Researchers analyzed data from about 13,000 Canadian adults. More than 1,000 of the women reported being physically abused before they turned 18 and about 900 said they had been diagnosed with a thyroid disorder.

The study was published online July 29 in the Journal of Aggression, Maltreatment & Trauma.

Long-term effects of childhood physical abuse on the thyroid "may be due to the way early traumas change the way an individual reacts to stress throughout life," study co-author Loriena Yancura, an associate professor in the family and consumer sciences department at the University of Hawaii, said in the news release.

"One important avenue for future research is to investigate potential dysfunctions in the production of the 'fight-or-flight' hormone, cortisol, among survivors of abuse," she added.

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Sense of Smell Determined by Genes, Study Says

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Ability to detect certain scents is highly individual, research suggests

By Robert Preidt

HealthDay Reporter

FRIDAY, Aug. 2 (HealthDay News) -- Genetic differences appear to explain why some people can smell certain odors and others can't, researchers say.

Using 10 different odors, the researchers tested nearly 200 people for their smell sensitivity and then analyzed the participants' DNA. For four of the odors tested, there was a link between smell sensitivity and certain genetic variants.

The four odors are malt, apple, blue cheese and violets, according to the findings, published online Aug. 1 in the journal Current Biology.

"We were surprised how many odors had genes associated with them. If this extends to other odors, then we might expect everyone to have their own unique set of smells that they are sensitive to," research team co-leader Jeremy McRae, of Plant and Food Research in New Zealand, said in a journal news release.

"These smells are found in foods and drinks that people encounter every day, such as tomatoes and apples. This might mean that when people sit down to eat a meal, they each experience it in their own personalized way," McRae said.

He and his colleagues also found that people's ability to smell these four odors was the same worldwide. That means that someone in Asia is just as likely to be able to smell one of the odors as someone in Africa or Europe.

The ability to smell one of these odors doesn't predict the ability to smell the others, the study also found. So if someone is good at smelling blue cheese, it doesn't mean they'll be good at smelling an apple next to it.

The genetic variants that affect the ability to smell these four odors are in or near genes that encode odorant receptors. The researchers explained that odor receptor molecules sit on the surface of sensory nerve cells in the nose. When certain chemical compounds float in the air, the nerve cells send a signal to the brain and give you the perception of a smell.

Richard Newcomb, co-leader of the project, said that knowing the compounds that people can sense in foods, as well as other products, will influence the development of future products. "Companies may wish to design foods that better target people based on their sensitivity, essentially developing foods and other products personalized for their taste and smell," he said in the news release.

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Could Dietary Tweaks Ease Type 1 Diabetes?

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Foods rich in amino and fatty acids may help preserve insulin production, study suggests

By Serena Gordon

HealthDay Reporter

FRIDAY, Aug. 2 (HealthDay News) -- Eating foods that contain certain nutrients may help people with newly diagnosed type 1 diabetes continue producing some insulin for as long as two years, a new study finds.

Although eating such foods doesn't alter the need to take insulin injections to treat type 1 diabetes, foods with leucine -- an amino acid -- and with omega-3 fatty acids may mean that less insulin is needed, according to the new research.

"After the diagnosis of type 1 diabetes, a branch-chain amino acid and long-chain fatty acid were related to C-peptide levels, which are important because they've been shown to improve control of glucose, and maybe help prevent complications," said Elizabeth Mayer-Davis, the study's lead author.

This is "very early work," however, and parents of children with type 1 diabetes need to continue to follow their child's doctor's orders with regard to insulin and any other medications, said Mayer-Davis, professor of nutrition and medicine and interim chairwoman of the department of nutrition at the University of North Carolina at Chapel Hill.

Foods containing leucine include dairy products, meat, soy products, eggs, nuts and whole wheat. Omega-3 fatty acids are found in fatty fish, especially salmon.

At least one expert wasn't convinced that these foods could make a difference in insulin production in patients with type 1 diabetes.

"Nutrition in type 1 diabetes is very difficult to evaluate," said Dr. Joel Zonszein, director of the Clinical Diabetes Center at Montefiore Medical Center in New York City. "It's possible that nutrition has a small effect, but people have been trying to connect nutrition to type 1 [diabetes] for more than 30 years. This study will not change my practice."

Type 1 diabetes is believed to be an autoimmune disease in which the body's immune system mistakenly attacks and eventually destroys the insulin-producing beta cells in the pancreas.

Insulin is a hormone that's necessary to metabolize the carbohydrates in food. When carbohydrates are processed into glucose, insulin helps that glucose get into the body's cells to be used as fuel for the body and brain. Without insulin, glucose can't enter the cells and it builds up in the blood.

People with type 1 diabetes often continue making some insulin, though not enough to nourish their bodies properly, for months or even years after diagnosis, according to background information included in the study. The more beta cells that are preserved and still making insulin, the less the chance of serious complications, according to the study.

To see if nutritional factors might contribute to the preservation of beta cells, Mayer-Davis and her colleagues reviewed data on more than 1,300 young people up to 20 years old who had been diagnosed with type 1 diabetes. Their average duration of diabetes was nearly 10 months.

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