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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Agencies
July 2,2020

London, Jul 2: The World Health Organisation says smoking is linked to a higher risk of severe illness and death from the coronavirus in hospitalised patients, although it was unable to specify exactly how much greater those risks might be.

In a scientific brief published this week, the U.N. health agency reviewed 34 published studies on the association between smoking and Covid-19, including the probability of infection, hospitalisation, severity of disease and death.

WHO noted that smokers represent up to 18% of hospitalised coronavirus patients and that there appeared to be a significant link between whether or not patients smoked and the severity of disease they suffered, the type of hospital interventions required and patients' risk of dying.

In April, French researchers released a small study suggesting smokers were at less risk of catching Covid-19 and planned to test nicotine patches on patients and health workers — but their findings were questioned by many scientists at the time who cited the lack of definitive data.

WHO says "the available evidence suggests that smoking is associated with increased severity of disease and death in hospitalized Covid-19 patients. It recommends that smokers quit.

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Agencies
February 23,2020

Los Angeles, Feb 23: According to researchers, if administered quickly, a common medication that reduces bleeding could be a treatment for bleeding stroke.

The Spot Sign and Tranexamic Acid on Preventing ICH Growth - Australasia Trial (STOP-AUST) was a multicenter, prospective, randomized, double-blind, placebo-controlled, phase 2 clinical trial using the antifibrinolytic agent tranexamic acid in people with intracerebral hemorrhage (ICH).

ICH is a severe form of acute stroke with few treatment options.

Tranexamic acid is currently used to treat or prevent excessive blood loss from trauma, surgery, tooth removal, nosebleeds and heavy menstruation. For this study, one hundred patients with active brain bleeding were given either intravenous tranexamic acid or placebo within 4.5 hours of symptom onset.

Researchers analyzed brain CT scans taken during the 24-hour period after treatment with tranexamic acid or placebo.

Researchers found a trend towards reduced hemorrhage expansion in the group treated with tranexamic acid, especially in those treated within 3 hours of the brain bleed. However, this trend was not statistically significant. The finding was consistent with previous research using the medication.

"Further trials using tranexamic acid are ongoing and focusing on ultra-early treatment - within 2 hours. 

This is where the greatest opportunity for intervention appears to be. Tranexamic acid is inexpensive, safe and widely available. Our results and others provide great impetus for further, focused research using this treatment," Nawaf Yassi said.

Larger trials focused on patient outcomes are required for this therapy to enter routine clinical practice.

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Agencies
June 4,2020

The World Health Organisation on Wednesday said that anti-malarial drug hydroxychloroquine (HCQ) will return to the solidarity trial for the potential treatment of coronavirus disease.

At a press conference in the WHO headquarters in Geneva, Director General Tedros Adhanom Ghebreyesus said: "On the basis of the available mortality data, the members of the committee recommended that there are no reasons to modify the trial protocol. The Executive Group received this recommendation and endorsed continuation of all arms of the solidarity trial, including hydroxychloroquine."

The world health body had temporarily suspended the usage of HCQ from the solidarity trial for coronavirus treatment on May 25 soon after a study published in one of the most reliable medical journals, which had suggested that the drug could cause more fatalities among COVID-19 patients.

However, the WHO chief said that the decision was taken as a precaution while the safety data was reviewed.

Ghebreyesus also said that the Data Safety and Monitoring Committee will continue to closely monitor the safety of all therapeutics being tested in the solidarity trial.

"So far, more than 3,500 patients have been recruited in 35 countries. WHO is committed to accelerating the development of effective therapeutics, vaccines and diagnostics as part of our commitment to serving the world with science, solutions and solidarity," he said.

Soon after HCQ was suspended from the trial, the Indian government had said that the antimalarial drug has been known for its benefits for a long time and its usage will be continued on the frontline workers, including police and healthcare professionals, as prophylaxis. The government had also said that studies were being conducted and the drug would be included in the clinical trial also for the treatment of coronavirus disease.

US President Donald Trump also had strongly advocated the use of HCQ and called it a "game-changer". He went to the extent of saying that he had taken the medicine.

Launched by WHO and partners, solidarity trial is an international clinical trial to find an effective treatment for COVID-19, including drugs to slow the progression of the disease or improve survival. The trial, which enrols patients from different countries, "will compare four treatment options against standard of care to assess their relative effectiveness against COVID-19", said WHO. 

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