Genomic architecture of human neuroanatomical diversity
Roberto Toro, Jean-Baptiste Poline, Guillaume Huguet, Eva Loth, Vincent Frouin, Tobias Banaschewski, Gareth J Barker, Arun Bokde, Christian Büchel, Fabiana Carvalho, Patricia Conrod, Mira Fauth-Bühler, Herta Flor, Jürgen Gallinat, Hugh Garavan, Penny Gowloan, Andreas Heinz, Bernd Ittermann, Claire Lawrence, Hervé Lemaître, Karl Mann, Frauke Nees, Tomá Paus, Zdenka Pausova, Marcella Rietschel, Trevor Robbins, Michael Smolka, Andreas Ströhle, Gunter Schumann, Thomas Bourgeron
Human brain anatomy is strikingly diverse and highly inheritable: genetic factors may explain up to 80% of its variability. Prior studies have tried to detect genetic variants with a large effect on neuroanatomical diversity, but those currently identified account for <5% of the variance. Here we show, based on our analyses of neuroimaging and whole-genome genotyping data from 1,765 subjects, that up to 54% of this heritability is captured by large numbers of single nucleotide polymorphisms of small effect spread throughout the genome, especially within genes and close regulatory regions. The genetic bases of neuroanatomical diversity appear to be relatively independent of those of body size (height), but shared with those of verbal intelligence scores. The study of this genomic architecture should help us better understand brain evolution and disease.
Haldane's Sieve 
PIQ and VIQ are pretty strongly correlated at the phenotypic level, and their genetic correlation is probably at least as high (these are not reported in the paper). The almost perfect genetic correlations of VIQ with ICV and BV and the almost zero genetic correlations of PIQ with ICV and BV are unexpected in this light. I would have liked to see confidence intervals for the estimates presented in the paper.
Hi Pete,
I’m the other of the paper. I have a supplementary table with all those values (confidence intervals, likelihood ratio test and p values), that I’ll try to upload to bioRXiv as well. From that table (Table S2 in the manuscript):
rG(VIQ,IPQ)=0.69±0.25, significantly larger than 0, with a LRT = 3.58, and P-value=0.03 (uncorrected).
In patients VIQ is often more affected than PIQ, and it seems to be determined to a larger extent by culture. Maybe even if their variability is regulated by similar genetic mechanisms, one is more affected by the environment than the other…
In that Table S2 I computed a matrix of all pairwise genetic correlations, and I had a figure showing a graph of correlations (using a PCA of the similarity matrix). Maybe I should add it to the paper…
hahaha, I mean ‘author’ (it’s very early here :D)