Gene SNP Associated with Intelligence Found

The Radical Environmentalist crowd insists that no genes related to human intelligence have yet been found. But this is not so. This article, published eight months ago in the journal Molecular Psychiatry on April 14, 2015 shows a rigorous finding of an association of an SNP in the CADM2 gene is associated with brain processing speed on the the Letter Digit Substitution Test (LDST) and the Digit Symbol Substitution Task (DSST).

Those two tests are generally considered to be tests of raw processing speed. The finding was robust and was found across 20 different cohorts of adults involving tens of thousands of subjects all over the world in the US, the UK, Ireland, Iceland, France, the Netherlands, Germany, Switzerland, Austria, Croatia, Italy, Finland, Australia, and Taiwan.

The following tests were used in the study: the Letter Digit Substitution Test (LDST), the Digit Symbol Substitution Task (DSST),Trail Making Test Parts A and B, the Letter Digit Substitution Test (LDST), the Digit Symbol Substitution Task (DSST), semantic and phonemic fluency tests, and the Stroop Color and Word Test.

GWAS for executive function and processing speed suggests involvement of the CADM2 gene

To identify common variants contributing to normal variation in two specific domains of cognitive functioning, we conducted a genome-wide association study (GWAS) of executive functioning and information processing speed in non-demented older adults from the CHARGE (Cohorts for Heart and Aging Research in Genomic Epidemiology) consortium.

Neuropsychological testing was available for 5,429–32,070 subjects of European ancestry aged 45 years or older, free of dementia and clinical stroke at the time of cognitive testing from 20 cohorts in the discovery phase. We analyzed performance on the Trail Making Test parts A and B, the Letter Digit Substitution Test (LDST), the Digit Symbol Substitution Task (DSST), semantic and phonemic fluency tests, and the Stroop Color and Word Test. Replication was sought in 1,311-21,860 subjects from 20 independent cohorts.

A significant association was observed in the discovery cohorts for the single-nucleotide polymorphism (SNP) rs17518584 (discovery P-value=3.12 × 10− and in the joint discovery and replication meta-analysis (P-value=3.28 × 10−9 after adjustment for age, gender and education) in an intron of the gene cell adhesion molecule 2 (CADM2) for performance on the LDST/DSST. Rs17518584 is located about 170 kb upstream of the transcription start site of the major transcript for the CADM2 gene, but is within an intron of a variant transcript that includes an alternative first exon.

The variant is associated with expression of CADM2 in the cingulate cortex (P-value=4 × 10−4). The protein encoded by CADM2 is involved in glutamate signaling (P-value=7.22 × 10−15), gamma-aminobutyric acid (GABA) transport (P-value=1.36 × 10−11) and neuron cell-cell adhesion (P-value=1.48 × 10−13). Our findings suggest that genetic variation in the CADM2 gene is associated with individual differences in information processing speed.

5 Comments

Filed under Genetics, Intelligence, Neuroscience, Psychology, Science

5 responses to “Gene SNP Associated with Intelligence Found

  1. Jason Y

    Again IQ isn’t a block to making money, the primary goal in life. Far from it. In fact, 85 are so IQ people can make 100,000 USD or more a year easily.

    Anyhow, even lower IQ people can learn things. They just can’t learn it fast. It’s like a slow computer download vs a fast one. Yes, there might be genes connectted to IQ which make knowledge absorbtion slower for some than others. But Big deal.

    • Jason Y

      Take Calculus. People are horrible at it. People drop out of the class, whatever level it is, like flies. It’s cause they can’t process the informaton (formulas, strategies) fast enough, not fast enough to cover one semester. I suppose it means they have a low math IQ, even though, due to pride, a lot of university students won’t want to admit it.

      Yeah, that’s another thing. People have different IQs for different subjects. One person bad at math is good at English etc..

      • Jason Y

        Actually even someone who is super slow at math, but does eventually learn it well, IS good at math, even though you might say thier math IQ is low.

      • Lin

        I wonder what percentage of ‘smarter’ calculus-capable students can do the following problems:
        1)Prove(Yes,I mean proper PROOF): (-1)(-1) = 1
        2)If f(x)–> A as x –>a AND g(x) –> B as x –> A
        Does g[f(x)] –> B as x –>a ?
        If the answer is YES, give a proof. Give a counter-example if the answer is NO
        3)Give an example of a function which is undifferentiable everywhere except at one point..
        4)Try an elementary approach to disprove the conspiracy theory the moon is hollow(or an alien spaceship)
        5)A ship is sailing towards a certain geometric point A on the ocean surface. A huge meteorite impacts the ocean and finally sank and rest on the ocean floor 1 km below A. Assume the ship survives the tidal waves and still keeps on course, what will happen as it approaches A ?

        • Jason Y

          Sorry if I make too many comments, but I will say something. I doubt if most Calculus students can do those things. At the very least, they can only do the small amount of Calculus the professor shows them, and many students can’t even do that.

          At my school, and it’s no wimpy school either, the professor had to make at least one test “take home”, and two of the tests he allowed “do overs” for partial credit. Also, the final had a take home portion for extra credit. (Note: even with all the mercy shown, some people still makes C and D grades and some fail.)

          Of course, there are schools tougher than mine where no mercy is shown. For instance, Tennessee Tech is considered a major engineering school and it’s lower level courses “weed out” all sorts of people, and were not talking about pot unfortunately.

          Now people who do well at the community college I go to, often head to Tennessee Tech as the next stop. However, since they got some mercy at community colleges, they don’t have to worry about the “weeding out” process.

          I don’t know why Calculus is so hard. Some people on a math help forum commented that in order to do Calculus you have to master stuff coming before it. However, that’s debateable. Anyhow, it is true people don’t master the prerequisites, and sometimes they are never taught the prerequisites.

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