Sunday, October 27, 2013

New Test For Autism Probably Not Test For Anything

This just in from the Science Takes Time Department: A study that came out a year ago touting a “genetic test for autism” has now been roundly refuted by a follow-up from another group. That
follow-up work indicates that the authors of the first study made several errors in their analysis. What they were identifying with their genetic screen was, at most, possible subtle differences in ancestry between two populations, but it likely was not autism or autism risk.

For the initial study, from an Australian-based group led by researcher Stan Skafidas, the authors claimed that the markers they’d used could predict autism risk in babies and young children. They reported a predictive accuracy of almost 72% using their panel of markers, and news stories about their work reflected this claim, although some autism experts questioned the results and their relevance at the time [Note: that linked post by Jon Brock also contains a timeline of related publications and comments from Skafidas, so of interest for those into the minutiae of these things].

Now it seems that such excitement may have been a fevered symptom of single study syndrome, which particularly seems to afflict autism news coverage.

Ed Yong, writing at The Scientist, does crisp work deconstructing the follow-up paper whose authors not only failed to replicate the results of the Skafidas study but also cleanly demonstrate where Skafidas and colleagues went wrong. This second paper, from a group led by senior author Benjamin Neale, could serve as a master class in what to do and not to do in these complex genetics analyses. For folks not interested in such an education, the bottom line is that the claims of the original work were so unusual that many geneticists saw them as red flags. This effort at replication showed no association between any of the genetic markers and autism risk when comparing a control group and a group of autistic people, each consisting of more than 5000 people. They also found no link when they combined the markers and compared a subset of the two groups.

Read the whole story at

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