Sunday, October 21, 2018

Geneticists have assembled the largest sets of African genomic data available to date, creating a resource that will help researchers understand the genetic structure of Africa as well as the effects of genetic variation on protein function and disease

The findings underscore the importance of including globally diverse participant cohorts in genetics research. The researchers collected and analyzed genome-wide data from 6,400 individuals from rural Uganda, including the whole genome sequences of 1,978 people within that group. They combined this with data from an additional 7,784 individuals from other African countries, in the first genome-wide association study (GWAS) to analyze multiple traits across Africa. "This study represents one of the largest and most comprehensive efforts to identify genetic associations with disease within African populations, and will provide a roadmap for large-scale GWAS across the region," said Ayesha Motala, MD, FRCP, a leader of the study and professor at the University of KwaZulu-Natal. "Prior to our work, there were only a few hundred whole genome sequences available from Africa," said Deepti Gurdasani, MD, PhD, from the Wellcome Sanger Institute. "Most of the information we had was from African-American populations, which didn't capture the full diversity of the continent." After compiling the data, Dr. Gurdasani and her colleagues assessed genetic similarities and differences within the cohort, identifying commonalities among those who migrated to Uganda from the same regions. They also found a complex mixture of similarities between the Ugandan genomes, ancient East African populations, and Eurasian genomes. These findings suggest that modern Ugandan genomes represent the complex history of migration in the region, and that they have been shaped by multiple mixture events over thousands of years, including mixture with genomes resembling those in modern Europe. In addition, the researchers examined genetic influences on a variety of traits and diseases in the larger GWAS cohort, identifying 10 new associations specific to African populations. For example, they discovered an association between a deletion in the HBA1/HBA2 gene, known to cause the blood disorder alpha thalassemia, and blood bilirubin levels. This deletion is common among Africans, found in approximately 22% of individuals, but rare among previously studied Europeans. "Although it correlates with disease, this variant has been shown to protect people from severe malaria, which presents a stronger advantage in Africa than in Europe and has enabled the variant to rise in frequency within Africa," Dr. Gurdasani explained. The study also found an association between HBA1/HBA2 deletion and the blood's level of the protein HbA1c, high levels of which are often used to diagnose diabetes. "The high frequency of thalassemia in some African populations may affect the accuracy of this test, as it can modify HbA1c independently of glucose levels," Dr. Gurdasani said. Beyond their own analysis, the researchers hope their data will help other scientists better understand the genetic diversity of African populations and develop cost-effective tools to capture genome variation for future studies. Future work will also include detailed mapping of the cause-and-effect relationships between genetic variants through examining functional impact of variants on gene expression. As next steps, the researchers plan to expand their genomic data set to populations across Africa, by sampling diverse indigenous populations, and expanding the GWAS to about 75,000 individuals.

Saturday, October 20, 2018

Geneticist says that there is no gay gene

In a large study of more than 490,000 men and women in the United States, Britain and Sweden, researchers discovered four genetic variants that occur more often in people who indicated on questionnaires that they had had same-sex sexual partners. Andrea Ganna, a geneticist at the Broad Institute of MIT and Harvard reported the results. Two of the variants were specific to men’s sexual partner choice. The other two influence sex partner choice for both men and women. Collectively, the DNA differences explained only 8% to 12% of the heritability of having same-sex partners. “There is no gay gene,” Ganna said, “but rather non-heterosexuality is influenced by many tiny-effect genetic factors.”

Tuesday, October 16, 2018

Democratic Senator Elizabeth Warren is facing a backlash after revealing a DNA test, which she says validates her claims of Native American heritage

The Cherokee Nation slammed the results for showing trace amounts of native DNA. President Donald Trump later took to Twitter to taunt Warren. Many analysts speculate that Warren, whose heritage Trump has often mocked, is running for president. "Even they don't want her," Trump said in response to the statement by the Cherokee Nation, the largest tribal nation in the United States. "Thank you to the Cherokee Nation for revealing that Elizabeth Warren, sometimes referred to as Pocahontas, is a complete and total Fraud!" he wrote on Twitter, referencing the daughter of the 17th-Century indigenous chief. Cherokee Nation Secretary of State Chuck Hoskin Jr said in a statement that "a DNA test is useless to determine tribal citizenship". "Using a DNA test to lay claim to any connection to the Cherokee Nation or any tribal nation, even vaguely, is inappropriate and wrong," Hoskin said, adding that current tests do not differentiate between peoples from the North and South American continents. Warren later tweeted: "DNA & family history has nothing to do with tribal affiliation or citizenship, which is determined only - only - by Tribal Nations". "I respect the distinction, & don't list myself as Native in the Senate."

Sunday, October 14, 2018

A Somalian whose deportation from Britain was dramatically halted after airline passengers staged a mutiny demanding his release was a convicted gang rapist who was being kicked out of the country because of his sickening crime

Officials escorting Yaqub Ahmed on a flight from Heathrow to Turkey were forced to abandon his deportation when around a dozen holidaymakers who felt sorry for him angrily intervened shortly before take-off. At one stage during the astonishing episode, filmed on mobile phones, one traveler complained: "They’re separating him from his family’", while others chanted "take him off the plane". When harassed security guards caved in and walked 29-year-old Ahmed off the Turkish Airlines flight, he was seen thanking those on board for their support as they cheered and applauded. One person was heard declaring: "You’re free, man!" But the passengers who thought they were doing a good deed were unaware that the man they were defending had been sentenced to nine years in jail for his part in a vicious gang rape of a teenage girl – and that another member of his gang later fought for Islamic State in Syria. Ahmed, 18 at the time of the rape and living in Clerkenwell, North London, is thought to have been granted refugee status after arriving in Britain from war-torn Somalia as a boy.

Saturday, October 13, 2018

Researchers at Mayo Clinic have identified three specific gene types that account for a known two-to-three-fold increase in myeloma diagnoses among African-Americans

Researchers also demonstrated the ability to study race and racial admixture more accurately using DNA analysis. "Myeloma is a serious blood cancer that occurs two to three times more often in African-Americans than Caucasians," says Vincent Rajkumar, M.D., a hematologist at Mayo Clinic and senior author of the study. "We sought to identifying the mechanisms of this health disparity to help us better understand why myeloma occurs in the first place and provide insight into the best forms of therapy." Dr. Rajkumar and his colleagues studied 881 patients of various racial groups. Researchers found that the higher risk of myeloma known to occur in African-Americans was driven by three specific subtypes of the cancer characterized by the presence of genetic translocations in cancer cells. Translocations are genetic abnormalities in cancer cells caused by the rearrangement of parts between nonhomologous chromosomes. The translocation researchers identified were t(11;14), t(14;16), and (t14;20). "Previous efforts to understand this disparity have relied on self-reported race rather than on genetic ancestry, which may have resulted in bias," explains Dr. Rajkumar. "A major new aspect of this study is that we identified the ancestry of each patient through DNA sequencing, which allowed us to determine ancestry more accurately." Dr. Rajkumar says that the probability of an individual having one of the three specific translocations responsible for myeloma was significantly higher in the 120 patients who researchers identified with the highest level of African ancestry compared to the 235 individuals identified with lowest level of African ancestry. "There are efforts to enroll more minorities in clinical studies, and this is important.," says Dr. Rajkumar. "However, it is equally, if not more important, to determine the mechanisms of racial disparities in terms of why cancers occur more often in certain racial groups. Our findings provide important information that will help us determine the mechanism by which myeloma is more common in African-Americans, as well as help us in our quest to find out what causes myeloma in the first place." Dr. Rajkumar says study results also are important because response to cancer treatments vary based on the genetic subtype of cancer, and these findings will help researchers develop more effective treatment strategies for African-Americans with myeloma.

Pediatric researchers have discovered common gene variants associated with migraines in African-American children

The research adds to knowledge of genetic influences on childhood migraine and may lead to future precision medicine treatments for African-American children with these intense headaches. "Scientists already know that migraines may run in families, and other researchers have discovered multiple genetic links to migraine in European adults," said study leader Hakon Hakonarson, MD, PhD, director of the Center for Applied Genomics at Children's Hospital of Philadelphia (CHOP). "However, this is the first large-scale genetic study of migraine in children and in African-Americans." The researchers performed genome-wide association studies (GWAS) in separate groups of African-American (AA) and European-American (EA) children from CHOP's pediatric network. One study compared 380 AA children with migraine to 2,129 ancestry-matched control subjects. Another study compared 599 EA children with migraine to 7327 EA controls. The scientists found a novel genetic susceptibility locus on chromosome 5, specifically 5q.33.1, that predisposed AA children to migraine, but was not significant for the EA children. The team then performed a replication study that confirmed this finding in an independent pediatric cohort of 233 AA migraine patients compared to 4038 AA control subjects without migraine. Further analysis of the risk locus on chromosome 5 implicated two genes, NMUR2 and GLRA1, both involved in signaling pathways in the central nervous system. The researchers said this finding was consistent with previous GWAS research in adults that pointed to genes involved in neurotransmitter release.