Genome-wide DNA methylation and gene expression analyses of monozygotic twins discordant for intelligence levels

Human intelligence, as measured by intelligence quotient (IQ) tests, demonstrates one of the highest heritabilities among human quantitative traits. Nevertheless, studies to identify quantitative trait loci responsible for intelligence face challenges because of the small effect sizes of individual...

Full description

Saved in:
Bibliographic Details
Published in:PloS one 2012-10, Vol.7 (10), p.e47081-e47081
Main Authors: Yu, Chih-Chieh, Furukawa, Mari, Kobayashi, Kazuhiro, Shikishima, Chizuru, Cha, Pei-Chieng, Sese, Jun, Sugawara, Hiroko, Iwamoto, Kazuya, Kato, Tadafumi, Ando, Juko, Toda, Tatsushi
Format: Article
Language:English
Subjects:
Adult
Analysis
Biology
Bipolar disorder
Bisulfite
Deoxyribonucleic acid
DNA
DNA biosynthesis
DNA methylation
DNA Methylation - genetics
Environmental factors
Epigenesis, Genetic
Epigenetics
Female
Gene expression
Gene Expression Profiling
Gene Expression Regulation
Gene sequencing
Gene set enrichment analysis
Genes
Genetic aspects
Genetic Association Studies
Genetic Loci - genetics
Genetic Testing
Genome, Human - genetics
Genome-wide association studies
Genomes
Genomics
GTPase-Activating Proteins - genetics
Guanosine triphosphatases
Humans
Individual differences (Psychology)
Intelligence
Intelligence - genetics
Ion channels
Male
Medicine
Methylation
Polymerase chain reaction
Psychological aspects
Quantitative trait loci
Reproducibility of Results
Reverse Transcriptase Polymerase Chain Reaction
Sequence Analysis, DNA
Social and Behavioral Sciences
Studies
Twins
Twins, Monozygotic - genetics
Up-Regulation - genetics
Young Adult
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Human intelligence, as measured by intelligence quotient (IQ) tests, demonstrates one of the highest heritabilities among human quantitative traits. Nevertheless, studies to identify quantitative trait loci responsible for intelligence face challenges because of the small effect sizes of individual genes. Phenotypically discordant monozygotic (MZ) twins provide a feasible way to minimize the effects of irrelevant genetic and environmental factors, and should yield more interpretable results by finding epigenetic or gene expression differences between twins. Here we conducted array-based genome-wide DNA methylation and gene expression analyses using 17 pairs of healthy MZ twins discordant intelligently. ARHGAP18, related to Rho GTPase, was identified in pair-wise methylation status analysis and validated via direct bisulfite sequencing and quantitative RT-PCR. To perform expression profile analysis, gene set enrichment analysis (GSEA) between the groups of twins with higher IQ and their co-twins revealed up-regulated expression of several ribosome-related genes and DNA replication-related genes in the group with higher IQ. To focus more on individual pairs, we conducted pair-wise GSEA and leading edge analysis, which indicated up-regulated expression of several ion channel-related genes in twins with lower IQ. Our findings implied that these groups of genes may be related to IQ and should shed light on the mechanism underlying human intelligence.
ISSN:1932-6203
1932-6203
DOI:10.1371/journal.pone.0047081