[Paleopsych] Dallas Morning News: Gene variant may depress IQ of males

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Gene variant may depress IQ of males
http://www.azstarnet.com/sn/printDS/105238
[This article appeared in many places. I don't know its original provenance, 
but different sources of the same text have been posted on several groups I 
subscribe to.

[This is just one more finding coming down the pike, and I would not attach 
too much significance to it, yet.]

    Published: 12.03.2005

    THE DALLAS MORNING NEWS

    DALLAS -- Scientists in North Carolina say they have identified a
    gene that affects IQ, a finding that, if confirmed, would be a
    significant step toward understanding the genetic basis for
    intelligence.
    The new research could also have ethical implications because the
    effect of the gene appears to be quite dramatic: The scientists say
    that males who inherit a particular version of the gene have, on
    average, an IQ that is 20 points lower than males who don't.
    "I have to admit, the ramifications of it are great," said Randy
    Jirtle, the Duke University biologist who led the new research,
    noting that current genetic-testing techniques can easily determine
    which males have that version.
    However, he stressed that the IQ results in his research were based
    on a group average; individual males carrying the gene version had a
    wide range of IQ scores. While females also can carry the variation,
    it does not appear to affect their IQ, he said.
    Jirtle reported the new findings last month at a scientific
    conference in Durham, N.C.
    As early as the 1920s, research suggested that genetics play a key
    role in determining a person's mental capabilities.
    But so far, connections between IQ and specific genes have been just
    correlations, with little supporting evidence. The new research,
    Jirtle and other experts said, will need to be replicated before it
    is considered definitive.
    Jirtle's research centers on a gene identified as IGF2R, for type 2
    insulinlike growth factor receptor. The gene governs the production
    of a protein that, among other jobs, affects cell growth. All people
    carry the gene, but some have a version with a slightly different
    code, Jirtle said. This variation, he and his colleagues found,
    correlates with a lower IQ.
    The researchers studied about 300 children with an average age of
    10. The children, all Caucasian, came from six counties in the
    Cleveland area. As a group, males -- but not females -- who had the
    variant gene had IQ scores about 20 points lower than males who
    didn't.