"In addition, the C allele of rs10784502 is associated, on average, with 9,006.7 mm3 larger intracranial volume, or 0.58% of intracranial volume per risk allele and is weakly associated with increased general intelligence by approximately 1.29 IQ points per allele."
Just tried and at 23andme it is possible to check this gene, at least with the latest version of their chip (v3).
Just got to "Browse raw data" and put "rs10784502" on the right of "a SNP:" and press "Go".
p.s. CT here, the most diffuse variant (the "best" one according to the article is CC).
