What the scientists are saying…
The Amish’s genetic advantage Members of an Amish community in rural Indiana carry a rare genetic mutation that protects them against type 2 diabetes – and may extend their lives. This discovery, reported in the journal Science Advances, could shed light on the ageing process and may even lead to new treatments for chronic diseases. The mutation affects a protein, PAI-1, that was first discovered in the Amish community in Berne, Adams County. It affects blood clotting, but has long been suspected of having an impact on ageing too. Mice genetically engineered to produce high levels of PAI-1 have been observed to lose their hair early and die young. Now, an extensive study of the Amish and their forebears has revealed that those carrying the mutation, which causes them to produce less PAI-1, have a zero rate of diabetes; among noncarriers, the rate is 7%. They also have lower insulin levels. Their telomeres (protective caps on chromosomes that have been linked to longevity) are 10% longer, and they live to 85, on average – ten years longer than their peers without the mutation. The researchers are now applying for permission to test a drug that mimics the effect of the gene by inhibiting the production of PAI-1 on patients known to be at risk of diabetes.
Improved test for Down’s Doctors have developed a new way of screening for Down’s syndrome that has had impressive first results. The method, called reflex DNA screening, starts like the conventional test: at ten to 14 weeks, the mother has a blood sample taken and an ultrasound scan, the results of which are then combined with her age to work out her risk of carrying a baby with Down’s, and two more serious conditions caused by chromosomal abnormalities, Edwards and Patau syndromes. Normally, at-risk mothers are then offered a further test, an amniocentesis, which involves using a needle to draw fluid surrounding the foetus or tissue from the placenta. With the new test, doctors send some of the blood already collected for another test, which looks at fragments of the foetus’s DNA that leak from the placenta to determine whether it has a chromosomal abnormality. The two-part procedure would spare many women needless worry, because they are only alerted to a problem if the second blood test comes back positive. Moreover, the method appears to produce more accurate results. When adopted for a little over a year by five NHS maternity units in the UK, it detected 95% of pregnancies affected by the disorders, compared with 81% for the conventional test, and resulted in far fewer false positives. Deep-sea animals contain plastic Crustaceans living nearly seven miles below the ocean’s surface have ingested fragments of plastic, scientists have discovered. Researchers from Newcastle University lowered a baited-trap tripod into the world’s six deepest ocean trenches and used this to collect animals from the seabed. In all of the locations, at least half of the creatures studied were found to have consumed microfibres – tiny particles of fabric used in synthetic clothing, polyethylene and PVC; in the case of the world’s deepest ocean chasm, the western Pacific’s Mariana Trench, every sample was contaminated. According to Dr Alan Jamieson, who led the study, the finding makes it “highly likely” that “there are no marine ecosystems left that are not impacted by [man-made] debris”.
The world’s oldest wine Humans were making wine 8,000 years ago – far earlier than previously thought. Archaeologists excavating a Neolithic settlement in Georgia found fragments of large clay vessels embedded in the floors of the ancient houses. When analysed, these were found to contain traces of tartaric acid, the fingerprint compound for grapes and wine. Previously, the oldest chemical evidence of winemaking came from the Zagros Mountains of Iran; there, the practice was dated to 5,400-5,000BC. The discovery adds to a growing body of evidence that within a short time of first domesticating crops and animals 12,000 years ago, humans developed relatively sophisticated habits. “Wine fermentation isn’t a survival necessity. It shows that human beings back then were about more than utilitarian activity,” said Dr Patrick Hunt, an archaeologist at Stanford University.