Scientists find genes linked to diabetes

A diabetic gives herself an insulin injection in the arm. Photograph: Lester V. Bergman/Corbis

Scientists have found six new genes linked to type 2 diabetes, a discovery that will improve understanding of how the disease develops.

Each of the disease variants of the genes raises the risk of developing diabetes by only a small amount, but scientists say the combined impact of the collection of genes could be powerful, and the discovery could help develop new forms of prevention and treatment. One of the genes has also been linked to prostate cancer.

Diabetes occurs when the body cannot regulate its blood sugar levels. It is thought to affect more than 2 million people in the UK and another 750,000 are unaware of their condition. In type 2 diabetes, which is associated with obesity and is the more common form of the disease, the body does not respond properly to insulin produced by beta cells in the pancreas, which also may be making less of the hormone.

In the study, published yesterday in Nature Genetics, 90 researchers from more than 40 European and US centres pooled genetic data gathered from more than 90,000 people. "The sort of studies we're doing are designed to pick up common variants," said Mark McCarthy of the University of Oxford, who led the research. "Across these six, some of the variants are in 10% [of the population], in other cases the one that's increasing the risk is the majority version that is in 90%."

McCarthy said inheriting a disease variant of any of the genes from either parent could increase a person's risk of developing type 2 diabetes by 10%-15%. "There'll be a few individuals who will have many of these risk variants and they'll have higher risk of diabetes than individuals who have been lucky enough to end up with very few."

Since none of the new genes were previously suspected of having a role in diabetes, there is still much work to do in working out what the genes are responsible for, though there are clues. "Virtually all of the genes [found so far] seem to be impacting on the ability of the beta cells to compensate for insulin resistance," he said.

He added that a particular surprise was that one of the genes found linked to type 2 diabetes was recently shown to play a role in prostate cancer. "One of the most exciting bits of this field is that we're finding lots of unexpected connections that sometimes genes seem to influence diseases that we hadn't previously thought of as connected."

Simon Howell, chairman of Diabetes UK, said: "It's remarkable that we still know so little about such a major condition as type 2 diabetes. By revealing new pathways by which the body normally keeps blood glucose levels under control, this research offers new opportunities for more effective ways of treating and preventing this condition."

The findings are the latest success in a relatively recent technique called the genome-wide association study.

A decade ago, genetics research usually involved looking in families with rare conditions, such as cystic fibrosis, to find rare single gene mutations that had big effects. But after the human genome project in 2000, which mapped every gene in the body, and subsequent improvements in screening technology, scientists are now able to carry out large-scale comparisons of huge numbers of people.

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Excavation starts at Stonehenge

Timewatch animation revealing the history of Stonehenge The first excavation inside the ring at Stonehenge in more than four decades gets under way on Monday. The two-week dig will try to establish, once and for all, some precise dating for the creation of the monument. It is also targeting the significance of the smaller bluestones that stand inside the giant sarsen pillars. Researchers believe these rocks, brought all the way from Wales, hold the secret to the real purpose of Stonehenge as a place of healing. The excavation at the 4,500-year-old UK landmark is being funded by the BBC. The work will be filmed for a special Timewatch programme to be broadcast in the autumn. 'Magical stones' The researchers leading the project are two of the UK's leading Stonehenge experts - Professor Tim Darvill, of the University of Bournemouth, and Professor Geoff Wainwright, of the Society of Antiquaries. We believe that this dig has a chance of genuinely unlocking part of the mystery of Stonehenge John Farren, BBC Timewatch editor Follow the dig with Timewatch They are convinced that the dominating feature on Salisbury Plain in Wiltshire was akin to a "Neolithic Lourdes" - a place where people went on a pilgrimage to get cured. Some of the evidence supporting this theory comes from the dead, they say. A significant proportion of the newly discovered Neolithic remains show clear signs of skeletal trauma. Some had undergone operations to the skull, or had walked with a limp, or had broken bones. Modern techniques have established that many of these people had clearly travelled huge distances to get to south-west England, suggesting they were seeking supernatural help for their ills. But Darvill and Wainwright have also traced the bluestones - the stones in the centre of Stonehenge - to the exact spot they came from in the Preseli hills, 250km away in the far west of Wales. Neolithic inscriptions found at this location indicate the ancient people there believed the stones to be magical and for the local waters to have healing properties. 'Scientific proof' Darvill and Wainwright hope the dig will demonstrate such beliefs also lay behind the creation of Stonehenge, by showing that the make-up of the original floor of the sacred circle at the monument is dominated by bluestone chippings that were purposely placed there. The last dig inside the Unesco World Heritage monument was in 1964 The dig will also provide a more precise dating of the Double Bluestone Circle, the first stone circle that was erected at Stonehenge. The original setting for this circle is no longer visible. The bluestones seen by visitors today are later re-erections. Archaeologists tried to date the first circle in the 1990s and estimated that it was put up at around 2,550BC; but a more precise dating has not been possible. Principally, this is because materials removed in earlier excavations were poorly recorded and cannot be attributed with any certainty to specific features and deposits. The 3.5m by 2.5m trench that will be excavated in the new effort will aim to retrieve fragments of the original bluestone pillars that can be properly dated. The BBC's Jon Kay talks to Geoff Wainwright about the dig The BBC-funded excavation goes ahead with the full support of English Heritage, which manages the site for the nation. "Theories about Stonehenge are cheap; proof is precious," commented BBC Timewatch editor, John Farren. "I'm delighted that Timewatch, the BBC's flagship history programme, is able to offer the possibility for some hard scientific proof to further our knowledge of the dating of Stonehenge and to bolster this remarkable new theory. "It's taken us 18 months' hard work to get all the elements for the dig in place." Professor Wainwright added: "This small excavation of a bluestone is the culmination of six years of research which Tim and I have conducted in the Preseli Hills of North Pembrokeshire and which has shed new light on the eternal question as to why Stonehenge was built. "The excavation will date the arrival of the bluestones following their 250km journey from Preseli to Salisbury Plain and contribute to our definition of the society which undertook such an ambitious project. We will be able to say not only why but when the first stone monument was built." Dr Simon Thurley, chief executive of English Heritage, commented: "Very occasionally, we have the opportunity to find out something new archeologically - we are at that moment now. "We believe that this dig has a chance of genuinely unlocking part of the mystery of Stonehenge." BBC Timewatch will follow the progress of the Stonehenge dig over the course of the next two weeks. Catch daily text and video reports on the programme's website. A BBC Two documentary will be broadcast in the autumn and will detail the findings of the investigation

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Greatest Environmental Threats of the Future -NanoMaterials, Manmade Viruses & Biomimetic Robots

Forget about rising global water levels: Researchers, policymakers and environmental campaigners have identified 25 potential future threats to the environment including nanomaterials, manmade viruses and biomimetic robots. In addition to well-publicized risks such as toxic nanomaterials, the acidification of the ocean and increasingly frequent extreme weather events, the list includes some spooky scifi sounding possibilities:

• Biomimetic robots that could become new invasive species.

• Experiments involving climate engineering, for instance ocean 'fertilisation' and deploying solar shields

• Increased demand for the biomass needed to make biofuel.

• Disruption to marine ecosystems caused by offshore power generation.

• Experiments to control invasive species using genetically engineered viruses.

William Sutherland, a zoologist at the University of Cambridge, led a series of horizon-scanning workshops where the threats where highlighted.

Some of the threats identified are more speculative, such as robots that imitate animal behaviour and microbes made from synthetic molecules and might eventually behave like invasive species.

Posted by Jason McManus.

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