New Genetic Roots For Intelligence Discovered

Summary: A new study reveals 52 genes implicated in intelligence, 40 of which are new discoveries.

Source: VRIJE University Amsterdam.

Intelligence is one of the most investigated traits in humans and higher intelligence is associated with important economic and health-related life outcomes. Despite high heritability estimates of 45% in childhood and 80% in adulthood, only a handful of genes had previously been associated with intelligence and for most of these genes the findings were not reliable. The study, published in the journal Nature Genetics, uncovered 52 genes for intelligence, of which 40 were completely new discoveries. Most of these genes are predominantly expressed in brain tissue.

“These results are very exciting as they provide very robust associations with intelligence. The genes we detect are involved in the regulation of cell development, and are specifically important in synapse formation, axon guidance and neuronal differentiation. These findings for the first time provide clear clues towards the underlying biological mechanisms of intelligence”, says Danielle Posthuma, Principal Investigator of the study.

The study also showed that the genetic influences on intelligence are highly correlated with genetic influences on educational attainment, and also, albeit less strongly, with smoking cessation, intracranial volume, head circumference in infancy, autism spectrum disorder and height. Inverse genetic correlations were reported with Alzheimer’s disease, depressive symptoms, smoking history, schizophrenia, waist-to-hip ratio, body mass index, and waist circumference.

Image shows DNA strands.

Future studies will need to clarify the exact role of these genes in intelligence in order to obtain a more complete picture of how genetic differences lead to differences in intelligence. NeuroscienceNews.com image is for illustrative purposes only.

“These genetic correlations shed light on common biological pathways for intelligence and other traits. Seven genes for intelligence are also associated with schizophrenia; nine genes also with body mass index, and four genes were also associated with obesity. These three traits show a negative correlation with intelligence”, says Suzanne Sniekers, first author of the study and postdoc in the lab of Posthuma. “So, a variant of gene with a positive effect on intelligence, has a negative effect on schizophrenia, body mass index or obesity.”

Future studies will need to clarify the exact role of these genes in intelligence in order to obtain a more complete picture of how genetic differences lead to differences in intelligence. “The current genetic results explain up to 5% of the total variance in intelligence. Although this is quite a large amount of variance for a trait as intelligence, there is still a long road to go: given the high heritability of intelligence, many more genetic effects are expected to be important, and these can only be detected in even larger samples”, says Danielle Posthuma.

About this neuroscience research article

Funding: Netherlands Organisation for Scientific Research funded this study.

Source: Danielle Posthuma – VRIJE University Amsterdam
Image Source: NeuroscienceNews.com image is in the public domain.
Original Research: Abstract for “Genome-wide association meta-analysis of 78,308 individuals identifies new loci and genes influencing human intelligence” by Suzanne Sniekers, Sven Stringer, Kyoko Watanabe, Philip R Jansen, Jonathan R I Coleman, Eva Krapohl, Erdogan Taskesen, Anke R Hammerschlag, Aysu Okbay, Delilah Zabaneh, Najaf Amin, Gerome Breen, David Cesarini, Christopher F Chabris, William G Iacono, M Arfan Ikram, Magnus Johannesson, Philipp Koellinger, James J Lee, Patrik K E Magnusson, Matt McGue, Mike B Miller, William E R Ollier, Antony Payton, Neil Pendleton, Robert Plomin, Cornelius A Rietveld, Henning Tiemeier, Cornelia M van Duijn & Danielle Posthuma in Nature Genetics. Published online May 22 2017 doi:10.1038/ng.3869

Cite This NeuroscienceNews.com Article
VRIJE University Amsterdam “New Genetic Roots For Intelligence Discovered.” NeuroscienceNews. NeuroscienceNews, 22 May 2017.
<http://neurosciencenews.com/genetics-intelligence-6742/>.
VRIJE University Amsterdam (2017, May 22). New Genetic Roots For Intelligence Discovered. NeuroscienceNew. Retrieved May 22, 2017 from http://neurosciencenews.com/genetics-intelligence-6742/
VRIJE University Amsterdam “New Genetic Roots For Intelligence Discovered.” http://neurosciencenews.com/genetics-intelligence-6742/ (accessed May 22, 2017).

Abstract

Genome-wide association meta-analysis of 78,308 individuals identifies new loci and genes influencing human intelligence

Intelligence is associated with important economic and health-related life outcomes. Despite intelligence having substantial heritability (0.54) and a confirmed polygenic nature, initial genetic studies were mostly underpowered. Here we report a meta-analysis for intelligence of 78,308 individuals. We identify 336 associated SNPs (METAL P < 5 × 10−8) in 18 genomic loci, of which 15 are new. Around half of the SNPs are located inside a gene, implicating 22 genes, of which 11 are new findings. Gene-based analyses identified an additional 30 genes (MAGMA P < 2.73 × 10−6), of which all but one had not been implicated previously. We show that the identified genes are predominantly expressed in brain tissue, and pathway analysis indicates the involvement of genes regulating cell development (MAGMA competitive P = 3.5 × 10−6). Despite the well-known difference in twin-based heratiblity2 for intelligence in childhood (0.45) and adulthood (0.80), we show substantial genetic correlation (rg = 0.89, LD score regression P = 5.4 × 10−29). These findings provide new insight into the genetic architecture of intelligence.

“Genome-wide association meta-analysis of 78,308 individuals identifies new loci and genes influencing human intelligence” by Suzanne Sniekers, Sven Stringer, Kyoko Watanabe, Philip R Jansen, Jonathan R I Coleman, Eva Krapohl, Erdogan Taskesen, Anke R Hammerschlag, Aysu Okbay, Delilah Zabaneh, Najaf Amin, Gerome Breen, David Cesarini, Christopher F Chabris, William G Iacono, M Arfan Ikram, Magnus Johannesson, Philipp Koellinger, James J Lee, Patrik K E Magnusson, Matt McGue, Mike B Miller, William E R Ollier, Antony Payton, Neil Pendleton, Robert Plomin, Cornelius A Rietveld, Henning Tiemeier, Cornelia M van Duijn & Danielle Posthuma in Nature Genetics. Published online May 22 2017 doi:10.1038/ng.3869

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