A 29-gene stretch of chromosome 16 known as 16p11.2, or 16p, is deleted or duplicated in roughly one percent of individuals with autism and duplicated in some individuals with schizophrenia. Researchers have struggled to sort out which genes in the region contribute to features of these disorders.

Using zebrafish allows for an unbiased screen of individual genes, says Nicholas Katsanis, professor of cell biology at Duke University in Durham, North Carolina, and lead investigator of the Nature study. “We tested all of them with exactly same protocol, with no prior expectation of what we were going to find,” he says.

His study shows that suppressing a little-known gene called KCTD13 in zebrafish leads to a 20 percent increase in head size. Conversely, expressing too much of the gene leads to a 20 percent decrease in head size.

This seems to mirror what happens in people. Individuals lacking one copy of 16p often have abnormally large heads, dubbed macrocephaly, whereas those with an extra copy tend to have abnormally small heads, or microcephaly.

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SFARI, May 2012.

The study was published earlier this month in Nature Methods.

Many thanks to Andrea Facheris of Soundtrack4u for granting permission to use the music in the video. The song is called “Symphony 5″ (a reworking of Beethoven’s), by the Robot Symphony Orchestra.

The Last Word on Nothing, May 2012.

The trouble is, researchers rarely publish accounts of a drug failing. And according to a study published last week in Pediatrics, this publication bias is making antidepressants look like a better option for treating autism than they really are.

Although antidepressants have not been specifically approved by the U.S. Food and Drug Administration to treat autism spectrum disorders, many physicians prescribe them ‘off-label’ to alleviate the repetitive behaviors that are one of the disorder’s core features. An estimated 15 to 25 percent of children with autism take a popular type known as selective serotonin reuptake inhibitors, or SSRIs, such as Prozac or Celexa.

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SFARI, May 2012.

Michael Wigler, professor at Cold Spring Harbor Laboratory in New York, and his collaborators sequenced the exome, or protein-coding parts of the genome, using DNA isolated from blood cells from 343 children with autism and their family members. The findings lend statistical heft to three other exome-sequencing studies published inNature earlier this month.

“This fourth Musketeer is the largest of all four, and really puts the nail in the coffin” regarding the abundance of damaging mutations in autism, says Jonathan Sebat, associate professor of psychiatry and cellular and molecular medicine at the University of California, San Diego, who was a postdoctoral fellow in Wigler’s laboratory but was not involved in the new work.

The new study, as well as two of the older papers, tapped into the Simons Simplex Collection (SSC), a genetic and medical repository of some 2,700 families with only one child with autism and unaffected siblings and parents.

Unlike the other three papers, the new one also identified intriguing genetic links between autism and fragile X syndrome, the most common inherited form of intellectual disability. An estimated one-third of children with fragile X are also diagnosed with autism.

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SFARI, April 2012.

So why don’t we hear more about that Y?

The male chromosome only carries about 60 genes, of which 2 have been linked to autism. Nevertheless, some new research on children born with extra sex chromosomes suggests that there may be more than meets the Y.

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SFARI, April 2012.

I grew up in the wake of the feminist movement, and boy am I glad about that. Gender inequalities still exist, of course (ahem). But since grade school, my parents, teachers and favorite after-school-TV-show characters have encouraged me to invest in my education and career, just like any ambitious man. And I have.

Alas, biology still holds a trump card: my closing fertility window. By the time I’m 38, my bank account may be pregnant, but my eggs will be fossils. In last week’s issue of New Scientist, I wrote about a far-out experimental solution: freezing pieces of my ovary. The premise of the story was that if this technology ever gets off the ground, it could fulfill the original promise of the birth control pill, allowing women to make career decisions without the pressure of a ticking clock.

And it’s such a satisfying premise, isn’t it, especially for science-loving feminists like me. But after five months of airing it, triumphantly, to everyone I know, and thinking about their responses, my enthusiasm has waned. The cultural limits on the age of motherhood, I’m afraid, are far stronger than the biological ones.

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The Last Word on Nothing, April 2012.

Aspergillus niger, a type of black mold, “could probably be found on every table-top in the world,” says Richard Summerbell, research director of biotech Sporometrics in Toronto. It can cause everything from black fuzz on onion bulbs, to toenail infections, to painful and itchy swelling and discharge from the ears of children who stick dirty toys inside.

But A. niger, Summerbell points out, is also a workhorse of industry. For example, it can turn sugars into citric acid, the white powder that’s ubiquitous in foods, beverages, detergents, cosmetics, and pharmaceuticals. The fungus can also produce useful enzymes, such as alpha-galactosidase, the main ingredient in the anti-flatulence pill Beano.

See the other five creepies at…

Discover, April 2012.

The clock started ticking for T. Wilson in 2008, when she turned 36. She had been divorced for seven years, and as a trainee surgeon she barely had time to sleep, let alone date. But her waning fertility was not interested in reasons for putting off a pregnancy. Faced with the possibility that she might never be a mother, Wilson was afraid.

She wanted to preserve her fertility but didn’t like what technology had to offer. At that point, the preferred option for thousands of women all over the world was to freeze their eggs, but Wilson was daunted by the prospect of hormone injections, high cost and the time off work. Then she consulted Sherman Silber, a surgeon in St Louis, Missouri, who suggested she might like to bank one of her ovaries.

It is a highly experimental option.

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New Scientist, April 2012.

Autism’s bafflingly diverse array of language deficits — from word repetition to unusual syllable stresses to speaking in a monotone or sing-songy voice or not at all — has always been a hot topic of research. But the vast majority of studies in the past 30 years have focused on semantics, or the meaning of words, and pragmatics, the way that intentions, implications, history and other subtle social contexts affect meaning.

In contrast, the new study, published online 21 March in Applied Psycholinguistics, is one of a handful to look at autism and syntax, or the rules that govern how sentences are structured. The researchers found that children with autism don’t understand reflexive pronouns such as ‘himself’ and ‘herself.’

“What we’re arguing here is that autistic kids have some real grammatical deficits, not just communication deficits,” says lead investigator Ken Wexler, professor of brain and cognitive science at the Massachusetts Institute of Technology.

This distinction is important, he adds, because many computational linguists, including Wexler himself, believe that grammatical abilities are controlled by specific, innate structures in the brain, whereas semantic and pragmatic skills are more complicated and learned over time. Sorting out which deficits are common in autism could shed light on the brain systems derailed in the disorder.

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SFARI, April 2012.

Using the pub’s wireless Internet connection, one of the researchers eagerly downloaded the first batch of data. It was disappointing: the analysis found no gene variants outside the MHC that were associated with MS. “We thought, all this work and once again MS eludes us,” recalls David Hafler, one of the leaders of the International Multiple Sclerosis Genetics Consortium (IMSGC).

The next morning, when the researchers convened again at the University of Cambridge, they were in for a pleasant surprise. “The guy who had downloaded the data said: ‘Oh, I made a mistake’,” recalls Hafler, who is now head of neurology at Yale University. When the analysis was done again, the program identified variants near two genes that play an important role in the workings of immune cells.

The hope, Compston says, is that studying these variants will point researchers towards shared biological pathways that would make good targets for drugs.

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Nature, April 2012.