Gene behind freckles, brown hair and blue eyes found

November 23, 2013

boards.weddingbee.comWashington, Nov 23: In the study of Icelanders, researchers uncovered an intricate pathway involving the interspersed DNA sequence, or non-coding region, of a gene that is among a few dozen associated with human pigmentation traits.

It is more common to find people with ancestors from geographic locations farther from the equator, such as Iceland, who have less pigment in their skin, hair and eyes.

The researchers, including scientists from the National Human Genome Research Institute (NHGRI), analysed data from a genome-wide association study (GWAS) of 2,230 Icelanders.

A GWAS compares hundreds of thousands of common differences across individuals' DNA to see if any of those variants are associated with a known trait.

"This study explains a complex molecular pathway that may also contribute insights into skin diseases, such as melanoma, which is caused by the interaction of genetic susceptibility with environmental factors," said NHGRI Scientific Director Dan Kastner.

Researchers focused on the interferon regulatory factor 4 (IRF4) gene, previously associated with immunity. IRF4 makes a protein that spurs production of interferons, proteins that fight off viruses or harmful bacteria.

The researchers noted from genomic databases that the IRF4 gene is expressed at high levels only in lymphocytes, a type of white blood cell important in the immune system, and in melanocytes, specialized skin cells that make the pigment melanin. The new study established an association between the IRF4 gene and the pigmentation trait.

"Genome-wide association studies are uncovering many genomic variants that are associated with human traits and most of them are found in non-protein-coding regions of the genome," said William Pavan, co-author and senior investigator, Genetic Disease Research Branch, NHGRI.

The Icelandic GWAS yielded millions of variants among individuals in the study. The researchers narrowed their study to 16,280 variants located in the region around the IRF4 gene.

They used an automated fine-mapping process to explore the set of variants in IRF4 in 95,085 people from Iceland. The data revealed that a variant in a non-coding, enhancer region that regulates the IRF4 gene is associated with the combined trait of sunlight sensitivity, brown hair, blue eyes and freckles.

The study was reported in the journal Cell.

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News Network
July 10,2020

Toronto, Jul 10: Pasteurising breast milk at 62.5 degrees Celsius for 30 minutes inactivates the SARS-CoV-2 virus that causes Covid-19, making it safe for consumption by babies, a study claims.

According to the research published in the Canadian Medical Association Journal, current advice for women with Covid-19 is to continue to breastfeed their own infants.

In Canada, it is standard care to provide pasteurised breast milk to very-low-birth-weight babies in hospital until their own mother's milk supply is adequate, the researchers said.

"In the event that a woman who is Covid-19-positive donates human milk that contains SARS-CoV-2, whether by transmission through the mammary gland or by contamination through respiratory droplets, skin, breast pumps and milk containers, this method of pasteurisation renders milk safe for consumption," said Sharon Unger, a professor at the University of Toronto in Canada.

The Holder method, a technique used to pasteurise milk in all Canadian milk banks at 62.5 degrees Celsius for 30 minutes, is effective at neutralising viruses such as HIV, hepatitis and others that are known to be transmitted through human milk, the researchers said.

In the latest study, the researchers spiked human breast milk with a viral load of SARS-CoV-2 and tested samples that either sat at room temperature for 30 minutes or were warmed to 62.5 degrees Celsius for 30 minutes.

They then measured for active virus, finding that the virus in the pasteurised milk was inactivated after heating.

More than 650 human breast milk banks around the world use the Holder method to ensure a safe supply of milk for vulnerable infants, the researchers said.

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Agencies
January 4,2020

Washington D.C., Jan 3: A new study has found out that diet significantly affects the mental health and well being of an individual.

The study was published in the journal European Neuropsychopharmacology.

"We have found that there is increasing evidence of a link between a poor diet and the worsening of mood disorders, including anxiety and depression. However, many common beliefs about the health effects of certain foods are not supported by solid evidence," said the lead researcher, Professor Suzanne Dickson.

According to the researchers, the link between diet and mental health can be firmly established in certain cases like that of the ability of a ketogenic diet being helpful for children with epilepsy and the impact of vitamin B12 deficiency on poor memory, depression and fatigue.

"With individual conditions, we often found very mixed evidence. With ADHD for example, we can see an increase in the quantity of refined sugar in the diet seems to increase ADHD and hyperactivity, whereas eating more fresh fruit and vegetables seems to protect against these conditions," said Dickson

But there are comparatively few studies, and many of them don't last long enough to show long-term effects," added Dickson.

The study further concludes that some food items can be associated with treatment and the betterment of certain mental health conditions.

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Agencies
June 20,2020

The World Health Organisation has warned that the COVID-19 pandemic is entering a "new and dangerous" phase. Thursday saw the most cases in a single day reported to the WHO.

Tedros Adhanom Ghebreyesus said the day had seen 150,000 new cases with half of those coming from the Americas and large numbers also from the Middle East and South Asia, the BBC reported.

He said the virus was still spreading fast and the pandemic accelerating.

He acknowledged people might be fed up with self-isolating and countries were eager to open their economies but he said that now was a time for extreme vigilance.

Maria van Kerkhove, technical lead of the WHO's COVID-19 response, told a press conference the pandemic is "accelerating in many parts of the world".

"While we have seen countries have some success in suppressing transmission and bringing transition down to a low level, every country must remain ready," she said.

Mike Ryan, the head of the WHO's Health Emergencies Programme, said that some countries had managed to flatten the peak of infections without bringing them down to a very low level.

"You can see a situation in some countries where they could get a second peak now, because the disease has not been brought under control," he said.

"The disease will then go away and reduce to a low level, and they could then get a second wave again in the autumn or later in the year."

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