Genes

Coffee Cravings May Spring From Your DNA

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Genes appear to influence how much caffeine you need

Anybody up for a steaming cup of Joe? Turns out your DNA may hold the answer.

New research suggests that your genes influence how much coffee you drink.

Researchers analyzed genetic data from more than 1,200 people in Italy, who were asked how much coffee they drank each day.

Those with a gene variant called PDSS2 drank one cup less a day on average than those without the variation, the investigators found.

Research involving more than 1,700 people in the Netherlands yielded similar findings, according to the study authors.

The findings suggest that PDSS2 reduces cells’ ability to break down caffeine. That means it stays in the body longer.

The upshot: People with the gene variant don’t need as much coffee to get the same caffeine hit as those without it, the researchers said.

“The results of our study add to existing research suggesting that our drive to drink coffee may be embedded in our genes,” said study author Nicola Pirastu. He is a chancellor’s fellow at the University of Edinburgh in Scotland.

“We need to do larger studies to confirm the discovery and also to clarify the biological link between PDSS2 and coffee consumption,” Pirastu added in a university news release.

By Robert Preidt

Source: https://medlineplus.gov/news/fullstory_160628.html

Genetics play a bigger role than environmental causes for autism

Genetics plays more of a role in the development of autism than environmental causes, according to new research published Sunday in Nature Genetics.

The study found that 52% of autism risk comes from common genes, while only 2.6% are attributed to spontaneous mutations caused by, among other things, environmental factors.

Genetics play a bigger role than environmental causes for autism

“These genetic variations are common enough that most people are likely to have some,” said Joseph Buxbaum, a researcher at the Mount Sinai School of Medicine and one of the lead authors on the study. “Each one has a tiny effect on autism risk, and many hundreds or thousands together make a significant risk.”

Using Sweden’s health registry, the researchers compared 3,000 people with autism to 3,000 people without autism to determine the degrees that common and rare genes, as well as spontaneous mutations, contribute to autism risk. The study authors also compared the study’s results with a parallel study of 1.6 million Swedish families that identified specific genetic risk factors.

Buxbaum says the presence of these common genes can only determine the risk of autism, not whether or not the condition will develop. And even though spontaneous mutations only account for a small percentage of autism risk, their effect is significant. “[Individuals] might have all the common variants there as part of their background risk, but it took this initial hit to push them over the edge,” Buxbaum said.

Chris Gunter, an autism researcher at the Marcus Autism Center and professor at the Emory University School of Medicine, says the findings of this study are similar to those reported in other studies.

“There is no one gene for autism,” Gunter said. “Instead there are many different genetic variations which each contribute a little bit to the risk of developing the group of symptoms we diagnose as autism.” She added that we still don’t know exactly how much these different factors contribute to the development of autism.

Once scientists accumulate more data on the autism population, Buxbaum says this new research could help develop a “risk score” – such as the one that exists for heart attacks – that would help patients determine the likelihood of family members developing autism.  “The autism field has changed dramatically,” Buxbaum said. “We now have immense power to find both common and rare and spontaneous mutations in autism. That’s really the exciting part.”

Source: cnn

New genetic cause of male reproductive birth defects revealed

birth-defects

Researchers have defined a previously unrecognized genetic cause for two types of birth defects found in newborn boys.

Lead author Dr. Dolores Lamb, director of the Center for Reproductive Medicine at Baylor, professor and vice chair for research of urology and molecular and cellular biology at Baylor, asid cryptorchidism and hypospadias are among the most common birth defects but the causes are usually unknown.

Cryptorchidism is characterized by the failure of descent of one or both testes into the scrotum during fetal development. In the adult man, the testes produce sperm and the male hormone, testosterone. Hypospadias is the abnormal placement of the opening of the urethra on the penis.

Both birth defects are usually surgically repaired during infancy.

Lamb and colleagues used a method of genome wide screening (essentially a molecular karyotype) called array comparative genomic hybridization to study children with these defects. The method looks specifically at changes in chromosomal regions that have undergone duplication or deletions too small to see under a microscope, termed copy number variations.

These genomic changes can alter gene dosage (gene gains or losses) resulting in a change in cell function.

In its analysis, the team showed that the cause of these birth defects in a subset of children with these defects of testis and penile development resulted from a change in the number of copies of a gene, VAMP7.

The role of VAMP7 gene duplication in causing these male birth defects was important because of the type of protein family it belongs to – it is a SNARE (Soluble N-ethylmaleimide-sensitive factor activating protein receptor) protein (a large protein superfamily consisting of more than 60 members in yeast and mammalian cell), Lamb said.

The report has been published in the journal Nature Medicine.

Source: yahoo news

Blame your genes for low tolerance of pain

DNA-double-helix-by-NHGRI

Researchers may have identified key genes linked to why some people have a higher tolerance for pain than others. Study author Tobore Onojjighofia and colleagues evaluated 2,721 people diagnosed with chronic pain for certain genes. Participants were taking prescription opioid pain medications.

The genes involved were COMT, DRD2, DRD1 and OPRK1. The participants also rated their perception of pain on a scale from zero to 10. People who rated their pain as zero were not included in the study. Low pain perception was defined as a score of one, two or three; moderate pain perception was a score of four, five or six; and high pain perception was a score of seven, eight, nine or 10.

Nine per cent of the participants had low pain perception, 46 per cent had moderate pain perception and 45 per cent had high pain perception.

The researchers found that the DRD1 gene variant was 33 per cent more prevalent in the low pain group than in the high pain group. Among people with a moderate pain perception, the COMT and OPRK variants were 25 per cent and 19 per cent more often found than in those with a high pain perception.

The DRD2 variant was 25 per cent more common among those with a high pain perception compared to people with moderate pain.

Source: Pune Mirror

‘I will do it tomorrow’ attitude hidden in genes

I-will-do-it-tomorrow-attitude-hidden-in-genes

Is “I will do it tomorrow” is all you hear every time you ask your kid to do homework? The secret of such a trait may well be trapped in his/her genes, a study reveals.

Those who procrastinate are also likely to be more impulsive and both the traits are linked to genes that one inherits, the study has found.

“Everyone procrastinates at least sometimes but we wanted to explore why some people procrastinate more than others and why procrastinators seem more likely to make rash actions and act without thinking,” said psychological scientist Daniel Gustavson of the University of Colorado Boulder in the US.

The researchers found that procrastination is indeed heritable, just like impulsivity.

Not only that, there seems to be a complete genetic overlap between procrastination and impulsivity – that is, there are no genetic influences that are unique to either trait alone, the study found.

For the study, researchers had 181 identical-twin pairs and 166 fraternal-twin pairs complete several surveys intended to probe their tendencies toward impulsivity and procrastination, as well as their ability to set and maintain goals.

The research appeared in the journal Psychological Science.

Source: Business standard

Fried Foods’ Effects May Be Greater In People With Obesity Genes

People with certain genes may be more susceptible to the fattening effects of fried food, a new study suggests.

In the research, people whose genes put them at high risk for obesity saw bigger changes in their body mass index (BMI) from eating fried food than people with a lower genetic risk for obesity.

For example, among women in the study with a high genetic risk for obesity, those who ate fried food four times a week had an average BMI that was 1 point higher compared to those who ate fried food less than once a week. That point amounts to about 6 pounds (2.7 kilograms) for a 5-foot-3 inch (1.5 meters) person. In contrast, among women with a lower genetic risk for obesity, those who ate fried food frequently had a BMI that was just 0.5 points higher than those who rarely ate fried food

The results suggest that some genes may “amplify the adverse effects of fried food consumption on body weight,” said study researcher Lu Qi, an assistant professor in the Department of Nutrition at Harvard School of Public Health.

The findings underscore the importance of eating less fried foods to prevent obesity, particularly for people who are genetically predisposed to weight gain, the researchers said.

Previously, this same group of researchers found that people’s genes affect the obesity risk they face from drinking soda.

Fried food and obesity

Previous studies have shown eating fried food increases people’s risk of obesity. However, these studies did not look at how this risk might vary depending on a person’s genes.

In the new study, researchers analyzed information from more than 37,000 men and women who took part in three large studies in the 1980s and 1990s. Every four years, participants answered questions about their food and beverage intake.

The subjects also had their genomes analyzed for the presence of any of 32 genetic markers linked to obesity. Each person received a score — based on the number and type of genetic markers the individual had — that reflected the subject’s genetic predisposition to obesity, or an obesity risk score.

Not surprisingly, those who ate fried food more frequently tended to have higher BMIs than those who ate fried food less often. But this link was strongest among those with the highest obesity-risk scores.

The people with the highest obesity-risk scores and also the most fried food consumption had the highest BMIs overall.

Fried food all right for some?

The findings held even after the researchers took into account other lifestyle factors that might affect obesity risk, such as consumption of soda and other sugar-sweetened beverages, and how much time people spent watching TV or exercising.

Still, the researchers noted that the study found only an association, and cannot prove that fried food causes obesity among people with certain genes. It’s possible that other unhealthy habits not taken into account in the study were responsible for the link.

The findings do not mean that people with a low genetic risk for obesity can overindulge in fried food, Qi said. He noted that, in the study, frequent consumption of fried food was tied to an increased risk of obesity, even for people with a low genetic risk of obesity.

In addition, fried food consumption is linked with other adverse health effects, such as an increased risk of cardiovascular disease, Qi said.

The findings support recommendations that encourage healthy eating for everyone, Qi said. In the future, it may be possible to tailor diet recommendations for people based on their genes, he said.

Source: Huffington Post

Woman’s IVF Prevented Fatal Brain Disorder in Her Children

A woman whose genes put her at high risk for a rare brain disorder was able to avoid passing on the condition to her children through a special in-vitro fertilization (IVF) procedure, according to a new report of the case.

The woman, a 27-year-old in the United States, had undergone genetic testing that showed she had inherited a gene that put her at risk for Gerstmann-Straussler-Scheinker (GSS) syndrome, a rare and fatal brain disorder seen in only a few families in the world. Symptoms of the condition usually appear between ages 35 and 55, and include progressively worsening speech, movement and memory problems.

To have children, the woman and her husband used IVF, an assisted-reproduction technique in which eggs from the mother are fertilized in a laboratory. But before implanting the embryos in the uterus, doctors took an extra step and screened the embryos for the GSS genetic mutation.

Source: Live science

33 new genes behind onset of cancer uncovered

A research team has found many new cancer genes – expanding the list of known genes tied to these cancers by 25 percent.

Moreover, the study shows that many key cancer genes still remain to be discovered. The Broad Institute-led research team’s work, which lays a critical foundation for future cancer drug development, also shows that creating a comprehensive catalog of cancer genes for scores of cancer types is feasible with as few as 100,000 patient samples.

Broad Institute founding director Eric Lander, senior co-author, said that the knowledge of genes and their pathways will highlight new, potential drug targets and help lead the way to effective combination therapy.

Over the past 30 years, scientists had found evidence for about 135 genes that play causal roles in one or more of the 21 tumor types analyzed in the study. The new report not only confirms these genes, but, in one fell swoop, increases the catalog of cancer genes by one-quarter.

It uncovers 33 genes with biological roles in cell death, cell growth, genome stability, immune evasion, as well as other processes.

The result has been published in the journal Nature.

Source: Zee news

Negative results may ‘not always’ imply reduced breast cancer risk

A new study has found that women who are members of families with BRCA2 mutations but who test negative for the family-specific BRCA2 mutations are still at greater risk for developing breast cancer compared with women in the general population.

Women with certain mutations in their BRCA1 or BRCA2 genes are at increased risk for breast cancer. However, the study suggested that it may not always be true.

“We found that women who test negative for family-specific BRCA2 mutations have more than four times the risk for developing breast cancer than the general population,” Gareth R. Evans from University of Manchester in the United Kingdom, said. “We also found that any increased risk for breast cancer is largely limited to BRCA2 families with strong family history and other genetic factors.

Evans said that it is likely that these women inherit genetic factors other than BRCA-related genes that increase their breast cancer risk. About 77 single nucleotide polymorphisms are linked to breast cancer risk.

He said that identification of additional SNPs is necessary to understand why some of the BRCA-negative women from BRCA families are at higher risk.

The authors noted that specialists should use caution when stating that a woman’s breast cancer risk is the same as that of the general population following a negative test, because it may not be true for some women who come from BRCA2 families with a strong family history.

The study is published in journal Cancer Epidemiology, Biomarkers and Prevention.

Source: ANI