GWAS for Executive Function and Processing Speed Suggests Involvement of the CADM2 Gene

C. A. Ibrahim-Verbaas et al., Nature, April 14, 2015

Abstract

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 5429–32070 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 1311-21860 subjects from 20 independent cohorts. A significant association was observed in the discovery cohorts for the single-nucleotide polymorphism (SNP) rs17518584 (discovery Pvalue=3.12 × 10−8) and in the joint discovery and replication meta-analysis (Pvalue=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 170kb 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.

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  • David Ashton

    Fascist filth, Nazi nonsense, Racist rubbish, Elitist evil – should these discoveries be allowed a “platform”?

  • Tim_in_Indiana

    Don’t worry…as soon as genetic testing for IQ is proven to be 100% effective, the argument will then switch to, if we wait just a few more years, we will then have the tools of genetic engineering to actually increase everyone’s IQ, not just test it. So all we have to do is wait a few more years and the problem of unequal IQ will be solved.

    Just wait and see–that will be the new argument.

    • Guest

      >>>Anna>>
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      >>>>>>>>>>>>>>>>>>>>>>>>>>>>>

  • JohnEngelman

    Is it me, or did C. A. Ibrahim-Verbaas get a failing grade in Freshman English? I think he is trying to say that a gene for IQ has been found. I am glad that when I took the SAT I did not have to answer five questions on the basis of this essay.

    • De Doc

      An extremely technically laden abstract. But, when discussing IQ and genes, perhaps one needs to hide the implications of this study’s results in scientific jargon.

  • propagandaoftruth

    Wha????

    First (according to last article)…thought is assumed to originate in a physical organ known as the brain. Now they’re telling me brains are genetically inherited like any other organ in the body?

    This is outrageous! What would Franz Boas say?

  • Hilis Hatki

    CADM2 gene is it part of the intelligence gene complex known as “memorization – regurgitation”.

  • Terry

    I’ll take their word for it.They are talking about computers,right?

  • Light from the East

    The article also suggests that a small pair of genes can determine a main characteristic of a human, especially complex functionality. A good example is that chimps and humans share 96% of gene but does that mean chimps demonstrate about 96% the same behaviors of humans? I think everybody knows the answer. The more complicated a kind of creature, the more important the characteristics from the small percentage of genes.

    • evilsandmich

      A good example is that chimps and humans share 96% of gene but does that mean chimps demonstrate about 96% the same behaviors of humans?

      Some more than others my friend, some more than others…

  • Hilis Hatki

    DNA is so over hyped, RNA does all the work and gets none of the glory. Seriously introns and exons are amazing, that certain sequences of DNA are “unread” after translation and before translation. Is the watch maker blind?

  • Tarczan

    ” Our findings suggest that genetic variation in the CADM2 gene is associated with individual differences in information processing speed.”

    No, it’s just that they didn’t have preschool.